Embodied self-other overlap in romantic love: a review and integrative perspective. Virginie Quintard, Stéphane Jouffe, Bernhard Hommel, Cédric A. Bouquet. Psychological Research, February 15 2020. https://link.springer.com/article/10.1007/s00426-020-01301-8
Abstract: Romantic love has long intrigued scientists in various disciplines. Social-cognitive research has provided ample evidence for overlapping mental representations of self and romantic partner. This overlap between self and romantic partner would contribute to the experience of love and has been found to be a predictor of relationship quality. Self-partner overlap has been mainly documented at the level of conceptual or narrative self, with studies showing confusion between one’s own and partner’s identity aspects, perspectives, and outcomes. But the self is not restricted to abstract, conceptual representations but also involves body-related representations, which, research has revealed, are linked to social-cognitive processes. In this article, we review the emerging evidence that romantic love involves not only a blurring of conceptual selves but also a reduction of the distinction between self and romantic partner at a bodily level. We discuss the potential function(s) of self-other overlap in romantic relationship at the level of body-related representations and consider possible mechanisms. We conclude with possible future directions to further investigate how romantic love engages embodied self-other representations involved in social interactions.
TEC: the Theory of Event Coding
ASL: the Associative Sequence Learning
Imitation
According to TEC and the ASL model, sensorimotor learning plays an important role in the development of shared bodily representations. Importantly, while both theoretical views suggest that the main source of learning is through execution and perception of one’s own movement, the perception of others’ movements may also contribute to the development of perception–action links (Heyes & Ray 2000; Hommel, 2018). These links can be created through the establishment of associations between self-produced and others’ perceived actions, during the experience of synchronous action or when being imitated (accounting for example for mirroring of opaque actions such as facial expression—self-produced actions that one cannot see, except in a mirror). Therefore, these models predict that perception of others’ actions that often co-occur with self-performed action is more likely to trigger a perception-compatible action than other possible actions. Accordingly, people spending more time together and sharing activities, like romantic partners, should show more imitation of each other’s actions. Consistent with this proposal, in a now famous study, it was revealed that romantic partners tend to become physically similar after twenty years of marriage (Zajonc, Adelmann, Murphy, & Niedenthal, 1987). Such similarities may be explained by reciprocal imitation of the partner’s facial and other bodily expressions over time, leading partnered individuals to incorporate the bodily expressions of the other in their own body representation. A recent study by Maister and Tsakiris (2016) has more directly investigated automatic imitation (as a behavioral index of embodied self-other overlap) in romantic relationships. In their study, romantically involved participants were instructed to open or close their mouth depending on the color of a target dot while viewing pictures of their partner vs. a friend who produced either the same or a diferent action. The interference between observed and executed action (automatic imitation) was found to be larger when participants were exposed to pictures of their romantic partner’s actions compared to pictures of their friend’s actions. This may indicate greater overlap in embodied representations between romantic partners as compared to friends, even though attentional efects (more attention being drawn to pictures of the romantic partner) cannot be excluded. Increased automatic imitation of the beloved may have important consequences, as it potentially implies greater reciprocal imitation between romantic partners. Indeed, given the well documented positive outcomes of behavioral mimicry (such as liking, trust, and closeness; Chartrand & Lakin, 2013), increased imitation of the beloved may play a signifcant role in romantic relationships by fostering liking and connection between lovers. In line with this, studies based on naturalistic observation of interacting individuals have demonstrated that the amount of rapport individuals feel with each other is correlated with the assessment of the amount of posture sharing during their interactions (Lafrance, 1979; Lafrance & Broadbent, 1976). It is interesting to note that people involved in a romantic relationship are less prompt to imitate an attractive alternative, especially when passionately in love (Karremans & Verwijmeren, 2008). From this reduced mimicry of attractive alternatives, which might contribute to relationship maintenance, it is tempting to conclude that imitation has a special status within the romantic relationship.
Overlapping (conceptual) selves in romantic love
Social-psychological research has provided various conceptualizations and models of romantic love (e.g., Berscheid & Walster, 1978; Sternberg, 1986). Among these, the selfexpansion model of love is a process-oriented model conceiving romantic love as the cognitive inclusion of the (cognitive representation of) romantic partner in the self (Aron & Aron, 1996; Aron, Aron, & Norman, 2004). This model frst posits a central human motivation to extend the self, in the sense that people seek to enhance their perspectives, resources, and identities, to improve their potential efcacy (i.e. their ability to accomplish goals) (Aron & Aron, 1986; Maslow, 1967). Second, close relationships, especially romantic relationships, are assumed to provide self-expansion through the inclusion of other in the self, a process by which partners become closer and develop overlapping self representations (Aron & Aron, 1996; Aron, Mashek, & Aron, 2004). Accordingly, the self is expanded in romantic relationships by including aspects of the other in the self: the partner’s resources, perspectives, and characteristics are to some extent treated as one’s own (Aron & Aron, 1996). The experience of self-expansion is rewarding and positive, in that it broadens one’s own potentialities. It is assumed that the exhilaration associated with romantic love would be related to the experience of such self-expansion through the inclusion of partner’s characteristics into one’s self content (Aron, Norman, Aron, McKenna, & Heyman, 2000). Consistent with this view, self-expansion has been linked to positive outcomes in romantic relationships, such as admiration for the romantic partner, greater levels of satisfaction, commitment, and passion (Aron et al., 2000; Fivecoat, Tomlinson, Aron, & Caprariello, 2015; Mattingly, Lewandowski, & McIntyre, 2014; Reissman, Aron, & Bergen, 1993; Schindler, Paech, & Löwenbrück, 2015). Moreover, to the extent romantic partner’s perspectives and identities are experienced as one’s own, these partner’s characteristics thus turn out to be cognitively linked to one’s sense of self, leading to an overlap of representations of self and other (Aron & Aron, 1986). Being in love thus entails a reduced distinction, or a greater confusion, between the self and the romantic partner (Aron et al., 1991; Mashek et al., 2003; Rusbult, Martz, & Agnew, 1998). In line with the idea of self-expansion through the inclusion of the romantic partner in the self, people involved in a romantic relationship report more and wider domains (i.e. an increased diversity in self-descriptive terms) in the contents of the self-concept than singles (Aron, Paris, & Aron, 1995). This result attests to an expansion of the self-concept which is thought to arise from the inclusion of romantic partner’s characteristics into one’s own self-representation. Furthermore, consistent with the view that love involves overlapping representations of self and partner, research based on the Inclusion of the Other in the Self (IOS) scale, a pictorial measure supposed to capture self-other overlap (Aron, Aron, & Smollan, 1992), showed that participants report more overlap with their romantic partner compared to with a close friend or a family member (Acevedo, Aron, Fisher, & Brown, 2012; Quintard, Joufre, Croizet, & Bouquet, 2018). Importantly, comforting the idea that self-other overlap plays a significant role in romantic relationships, IOS scores are predictors of relationship stability over 3 months, the degree of overlap being negatively related to the likelihood of relationship dissolution (Le, Dove, Agnew, Korn, & Mutso, 2010). A key prediction of the self-expansion model is that overlapping representations of self and romantic partner elicit selfother confusion. Consistent with this prediction, studies have shown confusion between partner’s and one’s own traits (Aron et al., 1991; Mashek et al., 2003), interests, or attitudes (Aron, Steele, Kashdan, & Perez, 2006). For example, Aron et al. (1991) found slowed response times in a “me/not me” decision task (i.e., does the trait describe me?) when romantically involved participants had to evaluate traits that were relevant only for self or partner, compared to shared traits, suggesting blurred self-other boundaries in romantic love (see also Smith, Coats, & Walling, 1999). Also, the typical drop of self-esteem observed when one experiences upward social comparison is no longer present when people are outperformed by their romantic partner, especially for those reporting a high level of closeness (Lockwood, Dolderman, Sadler, & Gerchak, 2004). Thus, people do seem to experience their partner’s outcomes as their own. Results from neuroimaging studies also suggest overlapping representations of self and romantic partner. Cerebral regions known to be involved in the processing of self-related information, such as anterior cingulate cortex, fusiform and angular gyri, are activated by the presentation of the beloved’s name or face (Aron et al., 2005; Ortigue, Bianchi-Demicheli, Hamilton, & Grafton, 2007). Moreover, these cerebral activations triggered by the evocation of the beloved are positively correlated with the IOS-scores reported by participants with respect to their partner (Acevedo et al., 2012). To sum up, several lines of evidence show a blurring of the distinction between self and romantic partner, in line with the model of romantic love as an inclusion of the partner in the self. A large part of this work dealt with individuals’ traits, interests or attitudes (Aron et al., 1991, 2006; Mashek et al., 2003), that is, abstract, conceptual forms of self-representation (Gallagher, 2000; Smith, 2008). However, romantic, intimate relationships involve embodied cues such as touch, physical proximity, and shared bodily experiences (Fiske, 2004). Moreover, as speculated in early formulations of the self-expansion model of love, “in close relationships one’s body also behaves as if it is the other’s body” (Aron & Aron, 1996, p. 50), implying that the inclusion of the romantic partner in the self encompasses the body. Self-partner processing at a bodily level may be an important aspect to consider in romantic relationships in the light of empirical and theoretical research suggesting that self-other representations and social relationships are grounded in sensorimotor processing and body-related representations (e.g. Barsalou, 2010; Smith, 2008). In the next section, we provide an overview of this line of work, focusing on self-other overlap at a bodily level and its potential role in social cognition. Then, we explain why it is relevant to approach romantic love from this perspective, addressing why romantic love would affect the overlap between self and romantic partner at the bodily level.
Functional mechanisms underlying self‑other confusion
Theoretical frameworks have successfully predicted that romantic love increases self-other overlap and the sense that representations of oneself and representations of the beloved one becomes less discriminable. While the social effects and implications of this increase in representational overlap are varied and substantial, it is not yet well understood how it actually works. On the basis of ASL and TEC frameworks, we argued above that shared bodily experiences with the romantic partner may partly explain stronger bodily self-other overlap, in that it would promote the development of sensorimotor links between, or integration of, self and partner actions. But romantic love does not only, or necessarily, involve shared bodily experiences, it also entails a strong affective component and social evaluation and attitudes, which are further potentially important modulatory sources of self-other overlap. Although models acknowledge that action–perception links can be modulated by factors such as social distance or attitudes, through top-down modulation (e.g. Heyes, 2011; Chartrand & Lakin, 2013; Wang & Hamilton, 2012), they remain relatively silent regarding the cognitive mechanisms involved. However, there are frst indications that romantic love might be systematically related to, and perhaps trigger a particular cognitive-control style that favors the integration of representations, be they social or not, over discrimination. The general idea that interpersonal relations might be systematically associated with particular styles of information processing has received quite some support in recent years. For instance, high (vs. low) social power has been suggested to lead to more abstract information processing (Smith & Trope, 2006) and, conversely, abstract thinking has been shown to raise one’s subjective sense of power (Smith, Wigboldus, & Dijksterhuis, 2008). More specifcally, it has been reported that love priming (via imagination instructions), as compared to sexual priming, promotes a global, integrative processing of information in a classical local/ global processing task (Förster, Özelsel, & Epstude, 2010; see also Förster, 2009). The idea that romantic love is associated with a global processing bias, accompanied by reduced attentional selectivity (de Fockert, Caparos, Linnell, & Davidof, 2011), is consistent with the outcomes of a recent study investigating the link between romantic love and sensitivity to irrelevant information (van Steenbergen, Langeslag, Band, & Hommel, 2014). Romantically involved participants were frst required to imagine or write about a romantic event and listen to their favorite love-related music. Then they completed two conflict tasks (a Stroop and a flanker task) indexing the ability to regulate interference from irrelevant information according to situational demands. The results showed a positive association between the intensity of passionate love (as reported on the Passionate Love Scale) and the degree of interference control: more intense loving was associated with reduced selectivity, leading to a stronger impact of irrelevant information. In other words, romantic love is accompanied by a global/integrative mode of cognitive processing, which would indeed be expected to reduce self-other discrimination. This observation raises the questions (1) how the hypothetical global/integrative mode reduces discrimination between self- and other-representations, (2) why this reduction covaries with the kinds of efects and behaviors that were found to accompany romantic love, and (3) why this mode is sensitive to romantic love. Even though none of these questions has been investigated in the context of romantic love already, available fndings suggest a preliminary scenario. With respect to the frst question, general models of cognitive control have suggested that adaptive behavior requires a dynamic balance between two conficting cognitive control states, persistence/selectivity and flexibility/integration (Cools & D’Esposito, 2011; Goschke, 2003; Hommel & Wiers, 2017)—a process that has been called metacontrol (Hommel, 2015). According to a recent formulation of this view (Hommel & Wiers, 2017), a metacontrol bias toward persistence/selectivity strengthens the top-down infuence of the current goal, which focuses the system on relevant information and creates a strongly selective processing state reinforcing mutual competition between alternative representations. Conversely, a metacontrol bias toward fexibility/ integration is characterized by the weak top-down influence of the current goal and weak mutual competition between alternative representations, which widens the focus and creates a more integrative processing mode. Furthermore, the individual pattern of persistence/flexibility tradeof would emerge from an interaction between various factors known to bias cognitive control, such as genetic predisposition (Colzato, Waszak, Nieuwenhuis, Posthuma, & Hommel, 2010), cultural learning (Hommel & Colzato, 2017), task constraints (Bonnin, Gaonac’h, & Bouquet, 2011; Mekern, Sjoerds & Hommel, 2019), and afect (Dreisbach & Goschke, 2004). Various fndings have provided evidence that participants biased towards persistence/selectivity outperform others in tasks that require the exclusion of irrelevant information but perform more poorly than others in tasks that require the conjoint processing of different kinds of information, while participants biased towards fexibility/ integration show the exact opposite pattern (for reviews, see Hommel, 2015; Hommel & Colzato, 2017). From this theoretical perspective, it would make sense to assume that romantic love induces a bias towards flexibility/integration.
According to this metacontrol approach, and now we turn to the second question, romantic love should reduce the impact of the current goal on information processing, which is consistent with the observation that viewing a picture of the romantic partner is associated with a deactivation of brain areas involved in the representation of task intentions (Bartels & Zeki, 2000, 2004; Zeki & Romaya, 2010). The approach would also predict more confict between alternative representations, given that mutual inhibition is reduced, which accounts for van Steenbergen et al.’s (2014) observation that the intensity of romantic love is accompanied by a loss of conflict control. Converging evidence comes from studies in which metacontrol biases towards flexibility/integration were experimentally induced by having participants engage in a divergent thinking task, which is taxing people’s flexibility (Guilford, 1967). This manipulation has been found to evoke behavior that is very similar to that evoked by romantic love: it promotes interpersonal trust (Sellaro, Hommel, de Kwaadsteniet, van de Groep, & Colzato, 2014) and the integration of the others’ actions into one’s own task representation (Colzato, van den Wildenberg, & Hommel, 2013). Hence, romantic love may generate a similar bias towards flexibility/integration, which would account for the blurring of boundaries between the self and the romantic partner, at both conceptual and bodily levels. But why would romantic love do this? This brings us to our third question. Metacontrol biases have been shown to depend on genetic predisposition and cultural molding—two factors that are rather permanent and stable—but also on situational factors (Hommel & Colzato, 2017). The best-investigated situational factor is mood, which in the case of positive mood has been demonstrated to promote metacontrol fexibility at the cost of persistence (Dreisbach, 2006; Dreisbach & Goschke, 2004). This is interesting for our purposes for no less than four interconnected reasons. First, positive mood has also been consistently found to improve divergent thinking (Baas, de Dreu & Nijstad, 2008), the task that apparently induces similar kinds of behavior than romantic love does. Second, inducing positive mood was found to reduce interference control in confict tasks in similar ways than romantic love does (van Steenbergen, Band, & Hommel, 2010). Third, both positive mood (Akbari Chermahini & Hommel, 2012; Dreisbach et al., 2005) and divergent thinking (Akbari Chermahini & Hommel, 2010, 2012) have been shown to rely on (presumably striatal) dopamine, the neurotransmitter that is assumed to underlie metacontrol (Cools & D’Esposito, 2011; Hommel & Colzato, 2017). And, fourth, romantic love has been linked to dopaminergic transmission (Fisher et al., 2006). Taken altogether, this picture implies that engaging in romantic love and similar positive emotions are neurally represented as and/or accompanied by tonic increases of (presumably striatal) dopamine. Given that metacontrol biases are assumed to emerge from the interaction of frontal and striatal dopaminergic activity, and that increases of striatal dopamine are related to a stronger bias towards flexibility (Hommel & Colzato, 2017), this means that romantic love and flexibility biases are sharing a neuromodular mechanism that is known to generate behavior that has been observed in romantic lovers
Conclusion and future directions
In this paper, we combined theories and empirical work from contemporary social cognition, experimental psychology and neurosciences, to address the outstanding question of self-other processing in the bodily domain within romantic relationships. Extending previous research on conceptual self-other representations, the reviewed empirical findings suggest a prominent overlap between self and partner at a bodily level in romantic love. Moreover, this bodily overlap has been repeatedly found to be related to the intensity of romantic feelings. Thus, the two forms of selfhood—bodily self and conceptual self—seem to be engaged in the creation of the unique, intimate link between lovers. Building on models of perception–action links [the Theory of Event Coding (TEC) and the Associative Sequence Learning (ASL)], we propose an integrative view of causes and consequences of embodied self-other overlap in romantic relationships. We suggest that the ability to share partner’s bodily states facilitates interactions and promotes behaviors strengthening the afective bond between self and partner. Hence, this view highlights the key role of shared bodily states in social functioning as embodied cues of connectedness (Smith, 2008). Furthermore, an important and original aspect of our proposal is that it articulates the role sensorimotor and afective experiences in self-other processing. We argue that bodily experiences shared with the romantic partner and afective states may play a role in promoting the integration of self and partner bodily representations. Our proposal, which is rooted in TEC, is partly consistent with other models suggesting that action–perception links acquired through sensorimotor experience may be suficient to explain the development of social cognitive abilities such as imitation and/or empathy (e.g. Brass & Heyes, 2005; Heyes, 2018; Keysers & Gazzola, 2009). Here we suggest that to fully account for the impact of these links on social cognition, it is necessary to assume regulatory processes (metacontrol states) biasing the discrimination between self- and other-representations. By the same token, these regulatory processes allowed us to explain how afective states associated with romantic love may contribute to the reduction of bodily boundaries between self and romantic partner.
Yet, the potential role of self-partner bodily merging and the underlying mechanisms are far from being understood. Future directions can be identified to further investigate how romantic love engages embodied self-other representations involved in social interactions. Conceptual self-other overlap (as indexed for instance by IOS-scores) in the romantic context has been found to correlate with intimacy, relationship commitment and satisfaction, and to be a predictor of long term relationship stability and quality (Agnew et al., 1998; Aron et al., 1991; Le et al., 2010). Much less is known however regarding selfother overlap in the bodily domain. Future research should explore the links between embodied self-other overlap and diferent aspects of the relationship (satisfaction, self-disclosure, emotional expression, level of intimacy…). Another valuable direction would be to test how bodily self-other overlap with the romantic partner, as indexed for instance by behavioral mimicry, in the early stage of the relationship is a predictor of future relationship outcomes. More broadly, further work should examine the association between embodied self-other overlap and social cognition processes associated with the beloved. Studies already found a positive association between the intensity of romantic feelings and self-partner overlap at a bodily level (Ortigue et al., 2010; Quintard et al., 2018). This brings about the exciting question of the causal role of blurred self-other bodily boundaries to romantic feelings or attraction. A promising direction would be to test whether imitation of the beloved or procedures creating confusion between one’s own and other’s body (such as interpersonal multisensory stimulation; Tajadura-Jiménez & Tsakiris, 2014) can afect self-partner relationship. Another interesting future direction is to explore the impact of reduced bodily boundaries between self and romantic partner on the representation of peripersonal space (i.e., the space within reach). This space, which is crucial for our interaction with objects and others, has been proven to be very plastic. It is expanded in presence of another person—especially if the person is cooperative (Teneggi, Canzoneri, di Pellegrino, & Serino, 2013) and it is updated following physical changes in one’s own body (Cardini, Fatemi-Ghomi, Gajewska-Knapik, Gooch, & Aspell, 2019). Interestingly, recent work using interpersonal multisensory stimulation has demonstrated that experimentally induced reduction of self-other bodily boundaries modifes the representation of the other’s peripersonal space—in the sense of a remapping onto one’s own space (Maister, Cardini, Zamariola, Serino, & Tsakiris, 2015). Such a modification of the representation of the other’s peripersonal space may afect the way one processes events related to the other and his/her behaviors. This calls for future investigations of whether peripersonal space boundaries between romantically involved individuals may be modified and how this may relate to reduced bodily boundaries between self and romantic partner. A frst step to address this fascinating question may be to test whether the presence of the romantic partner modifies our representations of peripersonal spaces differently from other individuals. An important, yet relatively unexplored, possible efect of self-other overlap is a transfer of (usually) positive self-evaluations to the other. This kind of transfer would explain why physically touching objects triggers ownership efects (i.e. the fact that we value more objects that we own; Beggan, 1992): owned/touched objects would be valued because of their association with the (positive) self. An outstanding question is to what extent this transfer applies to one’s romantic partner, and whether self-other bodily merging may sustain such an effect. Finally, as stressed earlier, only a few studies have been devoted to the examination of basic, domain-general cognitive processes in the context of romantic love. Cognitive skills such as self-regulation and self-control (i.e. cognitive skills related to cognitive control) have been connected with relationship maintenance (Finkel & Campbell, 2001; Ritter, Karremans, & van Schie, 2010). Recent work also suggests that romantic love involves particular cognitive control states (van Steenbergen et al., 2014). Identifying potential modes of cognitive processing associated with romantic love and specifying their links with both conceptual and embodied self-other overlap is thus another crucial direction for research on romantic cognition. We hope considering these future directions will shed some new light on cognition and behaviors associated with romantic love.
Sunday, February 16, 2020
Counterfactual thinking involves the mental simulation of alternatives to the past; it is associated to high neuroticism & low agreeableness
Looking Behind and Looking Ahead: Personality Differences in Counterfactual and Prefactual Thinking. Alison M. Bacon, Clare R. Walsh, Raluca A. Briazu. Imagination, Cognition and Personality, February 14, 2020. https://doi.org/10.1177/0276236620905810
Abstract: Counterfactual thinking (CFT) involves the mental simulation of alternatives to the past. In contrast, prefactual thinking (PFT) simulates potential outcomes that have yet to happen. Individuals differ in the extent to which they think in these ways, but we know little about how personality is implicated in these differences. This study investigated the relationship between Big Five personality traits and levels of spontaneous CFT and PFT embedded within a fictional diary entry. Results indicated that CFT was related to high neuroticism and low agreeableness, while PFT was related to low neuroticism and high agreeableness, as well as high extraversion. This suggests that CFT and PFT are, in part, dispositionally based and may be predicted by Big Five measures. This has implications for our understanding of individual differences in terms of the functionality of CFT and PFT and their potential influence on life outcomes.
Keywords: counterfactual thinking, prefactual thinking, Big Five, neuroticism, agreeableness, extraversion
Abstract: Counterfactual thinking (CFT) involves the mental simulation of alternatives to the past. In contrast, prefactual thinking (PFT) simulates potential outcomes that have yet to happen. Individuals differ in the extent to which they think in these ways, but we know little about how personality is implicated in these differences. This study investigated the relationship between Big Five personality traits and levels of spontaneous CFT and PFT embedded within a fictional diary entry. Results indicated that CFT was related to high neuroticism and low agreeableness, while PFT was related to low neuroticism and high agreeableness, as well as high extraversion. This suggests that CFT and PFT are, in part, dispositionally based and may be predicted by Big Five measures. This has implications for our understanding of individual differences in terms of the functionality of CFT and PFT and their potential influence on life outcomes.
Keywords: counterfactual thinking, prefactual thinking, Big Five, neuroticism, agreeableness, extraversion
This study did not detect any effect of daily caffeine intake on sleep duration, implying that habitual use of caffeine in real life may not coincide with laboratory findings
The dynamic relationship between daily caffeine intake and sleep duration in middle‐aged and older adults. Yueqin Hu Katelyn Stephenson Dalton Klare. Journal of Sleep Research, February 14 2020. https://doi.org/10.1111/jsr.12996
Abstract: The effect of caffeine on sleep has been well documented. However, most studies examined this relationship in laboratories or used a cross‐sectional design analysing between‐person differences. This study investigated the within‐person relationship between caffeine intake and sleep duration at home. In a national database, 377 participants (aged 35–85 years) completed a 7‐day diary study. Sleep duration was measured by Actigraphy and caffeine intake was self‐reported in sleep logs. Three analytic strategies were used. The average sleep duration and the average caffeine intake were not significantly correlated. Multilevel regressions using daytime caffeine intake to predict night‐time sleep, and using night‐time sleep to predict next day caffeine intake, also did not detect any significant effect. Then dynamical systems analysis was performed, where the daily change rate and change tendency of caffeine and sleep were estimated, and the relationship among these momentums was examined. Results revealed a significant effect of sleep duration on the change tendency of caffeine use: a shorter sleep duration predicted a stronger tendency to consume caffeine, and this phenomenon was only found in middle‐aged adults (aged 35–55 years) not in older adults (aged 55+). This study did not detect any effect of daily caffeine intake on sleep duration, implying that habitual use of caffeine in real life may not coincide with laboratory findings, and that using caffeine to compensate for sleep loss is the habit of middle‐aged adults, not the elderly. The advantage of using a dynamic approach to analyse interrelated processes with uncertain time lags is also highlighted.
Abstract: The effect of caffeine on sleep has been well documented. However, most studies examined this relationship in laboratories or used a cross‐sectional design analysing between‐person differences. This study investigated the within‐person relationship between caffeine intake and sleep duration at home. In a national database, 377 participants (aged 35–85 years) completed a 7‐day diary study. Sleep duration was measured by Actigraphy and caffeine intake was self‐reported in sleep logs. Three analytic strategies were used. The average sleep duration and the average caffeine intake were not significantly correlated. Multilevel regressions using daytime caffeine intake to predict night‐time sleep, and using night‐time sleep to predict next day caffeine intake, also did not detect any significant effect. Then dynamical systems analysis was performed, where the daily change rate and change tendency of caffeine and sleep were estimated, and the relationship among these momentums was examined. Results revealed a significant effect of sleep duration on the change tendency of caffeine use: a shorter sleep duration predicted a stronger tendency to consume caffeine, and this phenomenon was only found in middle‐aged adults (aged 35–55 years) not in older adults (aged 55+). This study did not detect any effect of daily caffeine intake on sleep duration, implying that habitual use of caffeine in real life may not coincide with laboratory findings, and that using caffeine to compensate for sleep loss is the habit of middle‐aged adults, not the elderly. The advantage of using a dynamic approach to analyse interrelated processes with uncertain time lags is also highlighted.
Saturday, February 15, 2020
My English sounds better than yours: Second-language learners perceive their own accent as better than that of their peers
My English sounds better than yours: Second-language learners perceive their own accent as better than that of their peers. Holger Mitterer, Nikola Anna Eger, Eva Reinisch. PLOS February 7, 2020. https://doi.org/10.1371/journal.pone.0227643
Abstract: Second language (L2) learners are often aware of the typical pronunciation errors that speakers of their native language make, yet often persist in making these errors themselves. We hypothesised that L2 learners may perceive their own accent as closer to the target language than the accent of other learners, due to frequent exposure to their own productions. This was tested by recording 24 female native speakers of German producing 60 sentences. The same participants later rated these recordings for accentedness. Importantly, the recordings had been altered to sound male so that participants were unaware of their own productions in the to-be-rated samples. We found evidence supporting our hypothesis: participants rated their own altered voice, which they did not recognize as their own, as being closer to a native speaker than that of other learners. This finding suggests that objective feedback may be crucial in fostering L2 acquisition and reduce fossilization of erroneous patterns.
Abstract: Second language (L2) learners are often aware of the typical pronunciation errors that speakers of their native language make, yet often persist in making these errors themselves. We hypothesised that L2 learners may perceive their own accent as closer to the target language than the accent of other learners, due to frequent exposure to their own productions. This was tested by recording 24 female native speakers of German producing 60 sentences. The same participants later rated these recordings for accentedness. Importantly, the recordings had been altered to sound male so that participants were unaware of their own productions in the to-be-rated samples. We found evidence supporting our hypothesis: participants rated their own altered voice, which they did not recognize as their own, as being closer to a native speaker than that of other learners. This finding suggests that objective feedback may be crucial in fostering L2 acquisition and reduce fossilization of erroneous patterns.
Environmental influence due to idiosyncratic experiences is dominant in the variation of intensity of aesthetic appraisal; genetic factors played a moderate role (heritability 26-41%)
Bignardi, Giacomo, Luca F. Ticini, Dirk Smit, and Tinca J. Polderman. 2020. “Domain-specific and Domain-general Genetic and Environmental Effects on the Intensity of Visual Aesthetic Appraisal.” PsyArXiv. February 7. doi:10.31234/osf.io/79nbq
Abstract: Visual aesthetic experiences are universally shared and uniquely diversified components of every human culture. The contribution of genetic and environmental factors to variation in aesthetic appraisal has rarely been examined. Here, we analysed variation in the intensity of aesthetic appraisal in 558 monozygotic and 216 dizygotic same sex adult twin pairs when they were presented with three kinds of visual stimuli: abstract objects, sceneries, and faces. We estimated twin resemblance and heritability for the three stimuli types, as well as a shared genetic factor between the three stimuli types. Genetic factors played a moderate role in the variation of intensity of aesthetic appraisal (heritability 26 to 41%). Both shared and unique underlying genetic factors significantly accounted for domain-general and domain-specific differences. Our findings are the first to show the extent to which variation in the intensity of aesthetic experiences result from the contribution of genetic and environmental factors.
Abstract: Visual aesthetic experiences are universally shared and uniquely diversified components of every human culture. The contribution of genetic and environmental factors to variation in aesthetic appraisal has rarely been examined. Here, we analysed variation in the intensity of aesthetic appraisal in 558 monozygotic and 216 dizygotic same sex adult twin pairs when they were presented with three kinds of visual stimuli: abstract objects, sceneries, and faces. We estimated twin resemblance and heritability for the three stimuli types, as well as a shared genetic factor between the three stimuli types. Genetic factors played a moderate role in the variation of intensity of aesthetic appraisal (heritability 26 to 41%). Both shared and unique underlying genetic factors significantly accounted for domain-general and domain-specific differences. Our findings are the first to show the extent to which variation in the intensity of aesthetic experiences result from the contribution of genetic and environmental factors.
Neuroticism robustly increases general dissatisfaction with welfare state programmes, yet they also appear to need these programmes more
Taking social policy personally: How does neuroticism affect welfare state attitudes? Markus Tepe Pieter Vanhuysse. Social Policy & Administration, February 5 2020 https://doi.org/10.1111/spol.12568
Abstract: The role of the “Big Five” personality traits in driving welfare state attitudes has received scant attention in social policy research. Yet neuroticism in particular—a disposition to stress, worry, and get nervous easily—is theoretically likely to be an important driver of welfare attitudes precisely because welfare states deliver social “security” and “safety” nets. Using cross‐sectional data from the German Socio‐Economic Panel, we study three distinct attitude types (dissatisfaction with the social security system, feelings of personal financial insecurity, and preferences for state provision) and multiple social need contexts (including unemployment, ill health, old age, and nursing care). Controlling for established explanations such as self‐interest, partisanship, and socialization, neuroticism does not systematically affect support for state provision. But it robustly increases general dissatisfaction with social security, as well as financial insecurity across various need contexts. Neurotic people are thus less happy with welfare state programmes across the board, yet they also appear to need these programmes more. This trait may be an important deeper layer driving other social attitudes.
Abstract: The role of the “Big Five” personality traits in driving welfare state attitudes has received scant attention in social policy research. Yet neuroticism in particular—a disposition to stress, worry, and get nervous easily—is theoretically likely to be an important driver of welfare attitudes precisely because welfare states deliver social “security” and “safety” nets. Using cross‐sectional data from the German Socio‐Economic Panel, we study three distinct attitude types (dissatisfaction with the social security system, feelings of personal financial insecurity, and preferences for state provision) and multiple social need contexts (including unemployment, ill health, old age, and nursing care). Controlling for established explanations such as self‐interest, partisanship, and socialization, neuroticism does not systematically affect support for state provision. But it robustly increases general dissatisfaction with social security, as well as financial insecurity across various need contexts. Neurotic people are thus less happy with welfare state programmes across the board, yet they also appear to need these programmes more. This trait may be an important deeper layer driving other social attitudes.
Attenuation of Deviant Sexual Fantasy across the Lifespan in U.S. Adult Nonoffending Males
Attenuation of Deviant Sexual Fantasy across the Lifespan in U.S. Adult Males. Tiffany A. Harvey, Elizabeth L. Jeglic. Psychiatry, Psychology and Law, Feb 13 2020, https://doi.org/10.1080/13218719.2020.1719376
Abstract: Deviant sexual fantasy is identified as a risk factor for sexual offending, yet no study has examined deviant sexual fantasy across the lifespan in nonoffending adult males. To bridge this gap, this study examined the frequencies of normative and deviant sexual fantasies among 318 nonoffending adult males in the United States. Participants were recruited via Amazon Mechanical Turk™. Participants took two inventories that assessed demographics and types of sexual fantasies. Normality tests, means tests, Kruskal–Wallis 1-way analyses of variance (ANOVAs), binary logistic regressions, and odds ratio post hoc analyses were conducted. Deviant sexual fantasies progressively declined across all three age groups, while normative sexual fantasy did not. Results suggest that deviant sexual fantasy changes across the lifespan. Applicability of the findings to applied settings, such as sexually violent predator evaluations, is discussed. Limitations and future considerations are addressed.
Key words: Deviant, fantasy, interest, lifespan, males, nonoffending, normative, sexual, sexual offending, United States
Abstract: Deviant sexual fantasy is identified as a risk factor for sexual offending, yet no study has examined deviant sexual fantasy across the lifespan in nonoffending adult males. To bridge this gap, this study examined the frequencies of normative and deviant sexual fantasies among 318 nonoffending adult males in the United States. Participants were recruited via Amazon Mechanical Turk™. Participants took two inventories that assessed demographics and types of sexual fantasies. Normality tests, means tests, Kruskal–Wallis 1-way analyses of variance (ANOVAs), binary logistic regressions, and odds ratio post hoc analyses were conducted. Deviant sexual fantasies progressively declined across all three age groups, while normative sexual fantasy did not. Results suggest that deviant sexual fantasy changes across the lifespan. Applicability of the findings to applied settings, such as sexually violent predator evaluations, is discussed. Limitations and future considerations are addressed.
Key words: Deviant, fantasy, interest, lifespan, males, nonoffending, normative, sexual, sexual offending, United States
The Economic Consequences of Increasing Sleep Among the Urban Poor: Offering high-quality naps at the workplace increased productivity, cognition, psychological well-being, and patience
The Economic Consequences of Increasing Sleep Among the Urban Poor. Pedro Bessone, Gautam Rao, Frank Schilbach, Heather Schofield, Mattie Toma. NBER Working Paper No. 26746, February 2020. https://www.nber.org/papers/w26746
Abstract: This paper measures sleep among the urban poor in India and estimates the economic returns to increased sleep. Adults in Chennai have strikingly low quantity and quality of sleep relative to typical guidelines: despite spending 8 hours in bed, they achieve only 5.6 hours per night of sleep, with 32 awakenings per night. A three-week treatment providing information, encouragement, and sleep-related items increased sleep quantity by 27 minutes per night without improving sleep quality. Increased night sleep had no detectable effects on cognition, productivity, decision-making, or psychological and physical well-being, and led to small decreases in labor supply and thus earnings. In contrast, offering high-quality naps at the workplace increased productivity, cognition, psychological well-being, and patience. Taken together, the returns to increased night sleep are low, at least at the low-quality levels typically available in home environments in Chennai. We find suggestive evidence that higher-quality sleep improves important economic and psychological outcomes.
Supplementary materials for this paper: randomized controlled trials registry entry https://www.socialscienceregistry.org/trials/2494
Abstract: This paper measures sleep among the urban poor in India and estimates the economic returns to increased sleep. Adults in Chennai have strikingly low quantity and quality of sleep relative to typical guidelines: despite spending 8 hours in bed, they achieve only 5.6 hours per night of sleep, with 32 awakenings per night. A three-week treatment providing information, encouragement, and sleep-related items increased sleep quantity by 27 minutes per night without improving sleep quality. Increased night sleep had no detectable effects on cognition, productivity, decision-making, or psychological and physical well-being, and led to small decreases in labor supply and thus earnings. In contrast, offering high-quality naps at the workplace increased productivity, cognition, psychological well-being, and patience. Taken together, the returns to increased night sleep are low, at least at the low-quality levels typically available in home environments in Chennai. We find suggestive evidence that higher-quality sleep improves important economic and psychological outcomes.
Supplementary materials for this paper: randomized controlled trials registry entry https://www.socialscienceregistry.org/trials/2494
Friday, February 14, 2020
Financial Robo-Analysts collectively produce a more balanced distribution of buy, hold, & sell recommendations than do human analysts, they seem less subject to behavioral biases & conflicts of interest
Coleman, Braiden and Merkley, Kenneth J. and Pacelli, Joseph, Man versus Machine: A Comparison of Robo-Analyst and Traditional Research Analyst Investment Recommendations (January 6, 2020). Available at SSRN: http://dx.doi.org/10.2139/ssrn.3514879
Abstract: Advances in financial technology (FinTech) have revolutionized various product offerings in the financial services industry. One area of particular interest for this technology is the production of investment recommendations. Our study provides the first comprehensive analysis of the properties of investment recommendations generated by “Robo-Analysts,” which are human-analyst-assisted computer programs conducting automated research analysis. Our results indicate that Robo-Analysts differ from traditional “human” research analysts across several dimensions. First, Robo-Analysts collectively produce a more balanced distribution of buy, hold, and sell recommendations than do human analysts, which suggests that they are less subject to behavioral biases and conflicts of interest. Second, consistent with automation facilitating a greater scale of research production, Robo-Analysts revise their reports more frequently than human analysts and also adopt different production processes. Their revisions rely less on earnings announcements, and more on the large, volumes of data released in firms’ annual reports. Third, Robo-Analysts’ reports exhibit weaker short-window return reactions, suggesting that investors do not trade on their signals. Importantly, portfolios formed based on the buy recommendations of Robo-Analysts appear to outperform those of human analysts, suggesting that their buy calls are more profitable. Overall, our results suggest that Robo-Analysts are a valuable, alternative information intermediary to traditional sell-side analysts.
Keywords: FinTech, Analysts, Robo-Analyst, Investment Recommendations
JEL Classification: G14, G24
Abstract: Advances in financial technology (FinTech) have revolutionized various product offerings in the financial services industry. One area of particular interest for this technology is the production of investment recommendations. Our study provides the first comprehensive analysis of the properties of investment recommendations generated by “Robo-Analysts,” which are human-analyst-assisted computer programs conducting automated research analysis. Our results indicate that Robo-Analysts differ from traditional “human” research analysts across several dimensions. First, Robo-Analysts collectively produce a more balanced distribution of buy, hold, and sell recommendations than do human analysts, which suggests that they are less subject to behavioral biases and conflicts of interest. Second, consistent with automation facilitating a greater scale of research production, Robo-Analysts revise their reports more frequently than human analysts and also adopt different production processes. Their revisions rely less on earnings announcements, and more on the large, volumes of data released in firms’ annual reports. Third, Robo-Analysts’ reports exhibit weaker short-window return reactions, suggesting that investors do not trade on their signals. Importantly, portfolios formed based on the buy recommendations of Robo-Analysts appear to outperform those of human analysts, suggesting that their buy calls are more profitable. Overall, our results suggest that Robo-Analysts are a valuable, alternative information intermediary to traditional sell-side analysts.
Keywords: FinTech, Analysts, Robo-Analyst, Investment Recommendations
JEL Classification: G14, G24
Household Electrification & Economic Development--Impacts can vary even across individuals in neighboring villages: Households that were willing to pay more for a grid electrification may gain more from electrification compared to households that would only connect for free
Does Household Electrification Supercharge Economic Development? Kenneth Lee, Edward Miguel, and Catherine Wolfram. Journal of Economic Perspectives—Volume 34, Number 1—Winter 2020—Pages 122–144. https://pubs.aeaweb.org/doi/pdfplus/10.1257/jep.34.1.122
Abstract: In recent years, electrification has re-emerged as a key priority in low-income countries, with a particular focus on electrifying households. Yet the microeconomic literature examining the impacts of electrifying households on economic development has produced a set of conflicting results. Does household electrification lead to measurable gains in living standards or not? Focusing on grid electrification, we discuss how the divergent conclusions across the literature can be explained by differences in methods, interventions, potential for spillovers, and populations. We then use experimental data from Lee, Miguel, and Wolfram (2019) — a field experiment that connected randomly-selected households to the grid in rural Kenya — to show that impacts can vary even across individuals in neighboring villages. Specifically, we show that households that were willing to pay more for a grid electrification may gain more from electrification compared to households that would only connect for free. We conclude that access to household electrification alone is not enough to drive meaningful gains in development outcomes. Instead, future initiatives may work better if paired with complementary inputs that allow people to do more with power.
For supplementary materials such as appendices, datasets, and author disclosure statements, see the article page at https://doi.org/10.1257/jep.34.1.122
Abstract: In recent years, electrification has re-emerged as a key priority in low-income countries, with a particular focus on electrifying households. Yet the microeconomic literature examining the impacts of electrifying households on economic development has produced a set of conflicting results. Does household electrification lead to measurable gains in living standards or not? Focusing on grid electrification, we discuss how the divergent conclusions across the literature can be explained by differences in methods, interventions, potential for spillovers, and populations. We then use experimental data from Lee, Miguel, and Wolfram (2019) — a field experiment that connected randomly-selected households to the grid in rural Kenya — to show that impacts can vary even across individuals in neighboring villages. Specifically, we show that households that were willing to pay more for a grid electrification may gain more from electrification compared to households that would only connect for free. We conclude that access to household electrification alone is not enough to drive meaningful gains in development outcomes. Instead, future initiatives may work better if paired with complementary inputs that allow people to do more with power.
For supplementary materials such as appendices, datasets, and author disclosure statements, see the article page at https://doi.org/10.1257/jep.34.1.122
From 1992... Paul Romer's "Two Strategies for Economic Development: Using Ideas and Producing Ideas"
From 1992... Two Strategies for Economic Development: Using Ideas and Producing Ideas. Paul M. Romer. The World Bank Economic Review, Volume 6, Issue suppl_1, 1 December 1992, Pages 63–91, https://doi.org/10.1093/wber/6.suppl_1.63
Abstract: The key step in understanding economic growth is to think carefully about ideas. This requires careful attention to the meaning of the words that we use and to the metaphors that we invoke when we construct mathematical models of growth. After addressing these issues, this paper describes two different ways in which ideas can contribute to economic development. The history of Mauritius shows how a poor economy can benefit by using ideas from industrial countries within its borders. The history of Taiwan (China) shows how a developing economy can be pushed forward into the ranks of those that produce ideas for sale on world markets.
Abstract: The key step in understanding economic growth is to think carefully about ideas. This requires careful attention to the meaning of the words that we use and to the metaphors that we invoke when we construct mathematical models of growth. After addressing these issues, this paper describes two different ways in which ideas can contribute to economic development. The history of Mauritius shows how a poor economy can benefit by using ideas from industrial countries within its borders. The history of Taiwan (China) shows how a developing economy can be pushed forward into the ranks of those that produce ideas for sale on world markets.
New neurocognitive-psychometrics account of mental speed that decomposes the relationship between mental speed and intelligence: They found that the speed of higher-order processing is greater in smarter individuals
Neurocognitive Psychometrics of Intelligence: How Measurement Advancements Unveiled the Role of Mental Speed in Intelligence Differences. Anna-Lena Schubert, Gidon T. Frischkorn. Current Directions in Psychological Science, February 13, 2020. https://doi.org/10.1177/0963721419896365
Abstract: More intelligent individuals typically show faster reaction times. However, individual differences in reaction times do not represent individual differences in a single cognitive process but in multiple cognitive processes. Thus, it is unclear whether the association between mental speed and intelligence reflects advantages in a specific cognitive process or in general processing speed. In this article, we present a neurocognitive-psychometrics account of mental speed that decomposes the relationship between mental speed and intelligence. We summarize research employing mathematical models of cognition and chronometric analyses of neural processing to identify distinct stages of information processing strongly related to intelligence differences. Evidence from both approaches suggests that the speed of higher-order processing is greater in smarter individuals, which may reflect advantages in the structural and functional organization of brain networks. Adopting a similar neurocognitive-psychometrics approach for other cognitive processes associated with intelligence (e.g., working memory or executive control) may refine our understanding of the basic cognitive processes of intelligence.
Keywords: intelligence, mental speed, psychometrics, cognitive modeling
Abstract: More intelligent individuals typically show faster reaction times. However, individual differences in reaction times do not represent individual differences in a single cognitive process but in multiple cognitive processes. Thus, it is unclear whether the association between mental speed and intelligence reflects advantages in a specific cognitive process or in general processing speed. In this article, we present a neurocognitive-psychometrics account of mental speed that decomposes the relationship between mental speed and intelligence. We summarize research employing mathematical models of cognition and chronometric analyses of neural processing to identify distinct stages of information processing strongly related to intelligence differences. Evidence from both approaches suggests that the speed of higher-order processing is greater in smarter individuals, which may reflect advantages in the structural and functional organization of brain networks. Adopting a similar neurocognitive-psychometrics approach for other cognitive processes associated with intelligence (e.g., working memory or executive control) may refine our understanding of the basic cognitive processes of intelligence.
Keywords: intelligence, mental speed, psychometrics, cognitive modeling
Crimes, deterrence, & paying for more security guards: Restricting guards in sparse, rural markets and requiring guards in dense, urban markets could be socially beneficial
The Race Between Deterrence and Displacement: Theory and Evidence from Bank Robberies. Vikram Maheshri and Giovanni Mastrobuoni. The Review of Economics and Statistics, January 23, 2020. https://doi.org/10.1162/rest_a_00900
Abstract: Security measures that deter crime may unwittingly displace it to neighboring areas, but evidence of displacement is scarce. We exploit precise information on the timing and locations of all Italian bank robberies and security guard hirings/firings over a decade to estimate deterrence and displacement effects of guards. A guard lowers the likelihood a bank is robbed by 35-40%. Over half of this reduction is displaced to nearby unguarded banks. Theory suggests optimal policy to mitigate this spillover is ambiguous. Our findings indicate restricting guards in sparse, rural markets and requiring guards in dense, urban markets could be socially beneficial.
JEL classification: K42
Keywords: deterrence, displacement, spillover, policing, bank security guards
Abstract: Security measures that deter crime may unwittingly displace it to neighboring areas, but evidence of displacement is scarce. We exploit precise information on the timing and locations of all Italian bank robberies and security guard hirings/firings over a decade to estimate deterrence and displacement effects of guards. A guard lowers the likelihood a bank is robbed by 35-40%. Over half of this reduction is displaced to nearby unguarded banks. Theory suggests optimal policy to mitigate this spillover is ambiguous. Our findings indicate restricting guards in sparse, rural markets and requiring guards in dense, urban markets could be socially beneficial.
JEL classification: K42
Keywords: deterrence, displacement, spillover, policing, bank security guards
Thursday, February 13, 2020
Mental experiment in which a person was split into two continuers: Most took decisions based on the continuity of memory, personality, and psychology, with some consideration given to the body and social relations
Putting your money where your self is: Connecting dimensions of closeness and theories of personal identity. Jan K. Woike, Philip Collard, Bruce Hood. PLOS, February 12, 2020. https://doi.org/10.1371/journal.pone.0228271
Abstract: Studying personal identity, the continuity and sameness of persons across lifetimes, is notoriously difficult and competing conceptualizations exist within philosophy and psychology. Personal reidentification, linking persons between points in time is a fundamental step in allocating merit and blame and assigning rights and privileges. Based on Nozick’s (1981) closest continuer theory we develop a theoretical framework that explicitly invites a meaningful empirical approach and offers a constructive, integrative solution to current disputes about appropriate experiments. Following Nozick, reidentification involves judging continuers on a metric of continuity and choosing the continuer with the highest acceptable value on this metric. We explore both the metric and its implications for personal identity. Since James (1890), academic theories have variously attributed personal identity to the continuity of memories, psychology, bodies, social networks, and possessions. In our experiments, we measure how participants (N = 1, 525) weighted the relative contributions of these five dimensions in hypothetical fission accidents, in which a person was split into two continuers. Participants allocated compensation money (Study 1) or adjudicated inheritance claims (Study 2) and reidentified the original person. Most decided based on the continuity of memory, personality, and psychology, with some consideration given to the body and social relations. Importantly, many participants identified the original with both continuers simultaneously, violating the transitivity of identity relations. We discuss the findings and their relevance for philosophy and psychology and place our approach within the current theoretical and empirical landscape.
Study materials, supporting analyses, and qualitative coding scheme: https://doi.org/10.1371/journal.pone.0228271.s001
Excerpts of discussion...
The fission scenario as scientific fiction: Benefits and validity concerns
Not all philosophers embrace the use of hypothetical scenarios in studying identity [129–131]. Some are critical of fission thought experiments, arguing that the intuitions derived from such fantasy accounts—in which anything goes—violate natural worlds and are therefore not valid measures of how people conceptualize identity in natural settings (e.g., [132]). Like contaminated test tubes in biochemical experiments, results obtained with faulty scenarios would have to be considered dubious [131]. Scholl [130] further argued that reactions to “bizarre scenarios” with forced responses might “tell us more about heuristic getting-through-the-experiment strategies than about actual metaphysical intuitions” (p. 580). One could compare these scenarios to visual illusions that generate experiences that are at odds with reality—but these experiences nevertheless often provide insight into the mechanisms that generate the illusion. For example, size and distance illusions reveal the computation the brain uses to calculate physical dimensions even in normal cases. Likewise, intuitions derived from cognitive processes during these unreal and outlandish examples may not be necessarily meaningful when measured against the constraints of reality [130] but rather cast light on how we use and reason with the concept of identity. While the participants’ open answers showed a degree of confusion in a minority of subjects, most answers reflected a well-considered and principled approach to the questions. Studies in experimental philosophy often feature unusual scenarios, and replicability in this sub-field compares favorably with replication rates in other domains of psychology [133].
Our science fiction scenario might be criticized for its lack of realism. It makes crucial assumptions that contradict the scientific understanding of how the components that we neatly separated in the story interact and co-depend on each other. According to Harle [68], a brain cannot be considered to be independent of the body; it would immediately adapt to a new body, rework the inner representation, and react to changes in social responses. Brain and body are interdependent in complex ways [39, 51, 63]. Motor learning [134] also involves two components, body and memory; muscles cannot work without neuronal input. The body and appearance component used in our studies could be understood to either include or not include brain matter. If included, all other components would depend on this component, as there can be no psychology without consciousness. If, alternatively, higher mental functions and consciousness are regarded as part of psychology or memory (which seems to be the approach taken by at least some participants), the brain, as a bodily organ that makes psychological functioning possible, can still be seen as source of tension in the scenario framework.
Participants responded to our scenario only from a first-person perspective. First-person evaluations of identity and survival might differ from third-person evaluations [128, 135]. For one thing, many legal, practical, and social concerns can be fulfilled by a person who is a spontaneous true copy of the original person. How much participants care about the disruption of continuity might therefore differ depending on whether the replaced person is them or a neutral other person [30]. Rorty [18] distinguished between an external observer’s perspective on individual identification and an individual’s internal perspective; features essential to an individual’s self-perspective might be irrelevant for an observer, and not all philosophers assume that first-person judgments have final authority [136, 137]. On the other hand, at least one study explicitly testing for the effect of perspective on intuitions about identity based on [28] found no substantial differences between a first-person and a third-person perspective [31]. At the same time, continuers were introduced from a third-person perspective. This shift was necessary to avoid a pre-judgment of the question how the original person relates to them, but might create a perceived distance. This could make it easier to give a negative answer to the survival question, but would have a symmetric influence on identity responses for both continuers.
It is less clear which perspective is better suited to evaluate claims about identity and survival. We assumed that involving the participant would be the best way to increase attention to the situation and diligence in responding. We induced a connection between our categories and their real-world instances, as perceived by the participants. A participant evaluating the importance of “body” in the money allocation problem will thus take the perception of her own body into consideration, which may lead to different results than when considering the importance of a body. This fact might play into our finding that a subgroup of participants placed a negative value on the continuity of the body.
On the other hand, our scenario avoids a complication common to many other fission scenarios: By splitting possessions and friends between survivors, it sidesteps the problem of nonsharable singular goods [34] with symmetric claims from two sides. These claims include access to special objects and, more significantly, the chance to engage in special relationships with others [51]. On the flipside, as Schechtman [138] argued, the scope and time frame of fission scenarios does not allow for societal reactions to the products of fission, which might include changes to the concept of persons and identity. Our approach avoids the confound of money being allocated for reasons of loss or pity, as both survivors emerge with their lives, bodies, and environments fully intact (if not unchanged). Williams [28] predicted a framing effect in the understanding of the scenario, a type of “leading the witness,” with a reversal of intuitions regarding identity depending on whether the story is told as involving body-swapping (transferring a person’s memory to a new body) or mind-manipulation (creating new memories in a person’s body). Empirical work has confirmed these predictions [31]. To counteract such potential framing effects, we used parallel language for all components varied in continuers; none of the components was privileged in the description of the scenario. Further, similar tensions involved in our scenario are discussed in section 1.3. in S1 Supporting Information.
Invoking hyperspace travel buys some degree of freedom, but at the cost of physical implausibility. However, factual impossibility does not prevent imaginability, and as Johnston [139] argued, “such per impossible thought experiments might nonetheless teach us about the relative importance of things that invariably go together” (p. 601). It is precisely because some aspects are not easily separated in realistic scenarios that we chose a fantasy scenario, allowing us to explore intuitions whose tests would otherwise be confounded.
Our scenario remains within the conventions of popular films (e.g., Total Recall or Blade Runner—both of which fittingly now exist in two versions) that deal with cases of copied or artificial memories and identities [140]. Body and mind transfer were considered intelligible by Locke [9], and the nature of personal identity is a recurrent theme in literature. Many readers have appreciated Franz Kafka’s tale of Gregor Samsa’s sudden metamorphosis into an insect [12] or Ovid’s metamorphosed subjects who survive the transformation [39]. Children become acquainted with bodily transfer in fairy tales like The Frog Prince [23, 120] or Hans Christian Andersen’s The Little Mermaid [39]. Johnson [141] takes this mere imaginability as an argument against declaring bodily continuity as a logical precondition for personal identity. Our scenario is no more fantastic than other thought experiments that have been employed to disentangle identity from its natural correlates—through neurosurgeons [6, 38, 51, 128, 142], amoeba-like duplication [127, 143], cloning [144], parallel universes [30], or even swamp-beings [66]. To come full circle, some of the philosophical conceptions and puzzle cases are reproduced in cultural creations and thereby further embedded into cultural consciousness [39]. It is possible that there is no theory of personal identity that would be able to “satisfy all intuitions about all devisable scenarios” (in [31], p. 297), but the advantage of imaginary scenarios lies in their power to isolate phenomena, which makes it possible to attend to specific aspects of our concepts [145]. In our scenarios we can separate changes from their ordinary causes and study decisions that may not occur in the world, but that probe concepts we apply to the world. In addition, our use of a novel paradigm limits the danger of previous exposure to similar questions and potential confusion, which is a concern with crowdsourced participants [146]. We therefore maintain that there is value in our approach of pitting dimensions that are generally accepted as dimensions of closeness against one another.
Dimensions of closeness
Our scenario bundles features into dimensions that might be further differentiated. For example, in contrast to [65], we did not differentiate between personality and psychology, on the one hand, and moral values, on the other. Evidence from several studies considering real-world personal transformations has indicated that identity judgments are most heavily influenced by changes or non-changes in moral values [65]. Changes in morality were judged to be more relevant than changes in (non-moral) personality attributes or memory. In a similar vein, Strohminger and Nichols [116] found that changes in morality in patients with neurodegenerative diseases strongly determined changes in perceived identity. Nunner-Winkler [21] reported on a study asking participants which changes would lead them to see themselves as a different person. Ideas about right and wrong and sex membership were considered to be quite important; appearance and money were considered less relevant (although some participants rated looks to be important, consistent with our distributional results).
The distinction between moral and nonmoral traits is somewhat ambiguous (e.g., conscientiousness was considered as a moral trait rather than a personality factor in [65]). One person’s morals do not and cannot exist in a social vacuum, moral consensus is central for co-ordination, affiliation and conflict resolution. Morality stands in complex relations to beliefs, values, behaviors and communities. It also depends on memory in nontrivial ways. Some of the induced changes in the scenarios even involved the loss of the moral faculty with a likely ripple effect reaching other dimensions of the self. If this perspective is true, the relevance of morality for personal identity might lie in these possibly disruptive consequences of changing one’s morals in relation to one’s environment and not because of its self-defining importance. Evidence for this interpretation is found in two studies demonstrating that changes in widely shared (and therefore less unique to the individual) moral values are considered to lead to more changes to the person than changes in controversial moral beliefs [106, 147]. For controversial moral beliefs, that might be considered most defining and informative for describing a person’s self, the effect was weaker than for memory. Also, the changes in memory induced by our scenarios would induce both errors of omission and errors of commission, which can have differential impacts on moral behavior [148]. In contrast, some studies focus mostly on omission errors due to memory changes (e.g., [118]), which are describes as having more limited effects on behavior towards others than changes in morality. In our scenarios, dimensions are replaced by random sampling from the participant’s reference population, which is a different operationalization of change. Heiphetz and colleagues [147] showed, for example, how the perceived change was mediated by perceived disruptions of friendships.
Some argue that morality is not even conceivable without personal identity [6, 10, 58]. Most people also seem to have inflated beliefs of their own morality [149]. In separate evaluations, our participants ranked memories and psychology to be more important for identity than moral values. Nonetheless, a further decomposition of the broad headings we used in our study would be feasible and interesting in future research. In particular, the role of moral traits and behavioral tendencies could be considered separately, even within a similar factorial setup as the one we employed.
The social dimension could be further differentiated, as well. Parents were considered to be more important than friends in Study 2, and Nunner-Winkler [21] reported similar findings. Of course, parents influence a person directly through the transmission of genes as well as indirectly through instruction and parenting behavior; changing one’s parents cannot be considered a merely social manipulation and could well have an impact on every other dimension.
In our scenario, changes in memory are considered universal and all-or-nothing. In real life, however, memories of self or self-knowledge seem to be better preserved than other knowledge, even in semantic dementia [20], and a subjective belief of self-persistence is demonstrated by patients with Alzheimer’s disease [150]. Alternatively, the sense of self may be impaired while episodic memories stay intact—as in the case of R.B. [67]. Further, separating specific psychological aspects or memory from a person’s social context and network of activities might prove impossible in practice [18]. There is also some overlap between criteria based on psychology and memory, but under the assumption that two organisms with the same memories might nonetheless differ in personality and psychology (e.g., based on differences in needs, intentions, values, or goals), it is not necessary that the criteria coincide. In fact, the psychological continuity criterion has been proposed as a critique of a narrow Lockean focus on memory [11].
Critics of our scenario might further object that our random collage of features in the two continuers destroys the causal connection between past and present states necessary for identity [6, 30]. Preschool children already individuate objects and persons spatio-temporally [23, 151] and, following Sagi and Rips [152], causal histories receive special attention in linguistic disambiguation in discourse. In all our scenarios (except the two extreme cases with exact duplicates), change in characteristics was induced by an accident, an unusual life event that disrupts spatio-temporal continuity. This fact might strengthen impressions that identity is not preserved. According to data reported in [21], for example, participants regarded changes in attitudes or beliefs that were due to normal life experiences as non-consequential for identity judgments—as opposed to changes induced by brainwashing, severe medical conditions, or accidents. Therefore, the nature of the transformation might play a role in our participants’ judgments. Note that both continuers underwent the same procedure, so this factor cannot explain differential assessments. Although the abruptness and symmetry of the original person’s transformation prevents the application of spatio-temporal continuation criteria, participants might still construct “fictive causal histories” [153] to assess which of the two continuers might have the better chance of being the result of changes within an ordinary life.
Finally, for a continuer to acquire a random set of possessions, these would have to materialize from somewhere. Our scenario also assumes that this change in possessions can leave memory, psychology, friends, and appearance untouched. This is incompatible with the reality that some of our memories are intertwined with objects in our possession and the difference between owning or not owning status symbols, for example, can impact self-value, build and burn bridges with others, and change perceptions of their owner.
Towards a process model of re-identification
Our studies allow to make some progress in the analysis of decisions involved in determining personal identity. Like Rips and colleagues [17], who develop the causal continuer model based on Nozick’s theory, we are interested in the decision process. Decision processes, as implemented by human beings, are often insufficiently described by functions merely predicting decision outcomes. A further analysis of the decision processes needs to address questions of information search: Which persons are considered as continuers? When and why is the search for possible continuers stopped? Which dimensions are considered in the subjective closeness metric, and how are these dimensions integrated? We showed some results compatible with decision-making following the closest continuer logic. Is there further evidence for the three steps being followed in a specific sequence—the fast-and-frugal tree in Fig 1 would not yield different outcomes if the first three levels changed their relative position—and how stable is this process across individuals? A structurally similar model of decision making has been proposed for explaining the phenomenon of choice deferral [154, 155]. When faced with a selection of possible alternatives, choice in the 2S2T-model [155] is deferred for one of two reasons. First, none of the options is good enough and surpasses a decision threshold or second, too many options are good enough, surpassing the threshold but it becomes difficult to choose the best option. Of course, personal re-identification is not simply preferential choice but the analysis of the decision process might still be informed by the analysis of related or parallel processes in other domains.
While the mathematical form of weighted-additive linear models implies weighting and adding, many other operations, such as lexicographic stepwise procedures that ignore (sometimes most of the) variables in the equation [35] would still be captured by this model [156]. Brook [12] argued for a model of personal re-identification that starts with psychological factors and only considered other dimensions if the information is missing (or inconclusive). Variance in choosing and applying criteria might again be related to other individual differences [41, 42]. Based on the variations in our chosen design for this study, it is not yet possible to build cognitive models of participants’ decisions. It is, for example, unclear whether an appropriate model should be stochastic, as in [17], or deterministic.
Our scenarios varied factors that should mostly influence the assessment of closeness and only indirectly the decision-making based on these assessments. Future research could shift this focus to the subsequent stages of the procedure. Thus, specific exit nodes of the decision tree in Fig 1 could be investigated. For example, is there a minimum level of closeness required for participants to determine that any of the continuers is identical to the original person? Do participants share the intuition that a fission resulting in multiple exact copies does not preserve identity, and would this depend on the level of closeness? What type of difference is considered to be sufficient to single out a closest continuer?
Both studies in this manuscript confronted participants with two continuers. Future studies could increase the number of continuers. A different approach could focus on one continuer by either keeping a second continuer constant, or moving from paired comparisons to binary reidentification. Previous studies have explored variants of thought experiments compatible with these ideas. White [157] implemented one such scenario, focusing on the likelihood that a living person might be the reincarnation of a deceased person (see also [65]). For reincarnation judgments, distinctiveness was found to guide decisions. Similar to our sci-fi scenario, this setting might introduce specific assumptions about the process of reincarnation that could guide responses. For example, the importance of body similarity might be evaluated to be a lot lower than when responding to a scenario, in which a ship wreck survivor is returned from an island and matched to missing persons, and the importance of moral attributes to be higher. In contrast to the second scenario, the reincarnation scenario prevents the use of causal histories that are useful for person tracking [1].
It might also be the case that different practical concerns demand different criteria of identity. We investigated the parameters of identity in the context of re-identification and compensation. Other practical concerns, such as attributing blame, responsibility, or guilt, or allocating punishments and rewards, might trigger different responses, as the criteria of identity might shift or current properties of persons might become more relevant than historical properties and re-identification questions [10, 158].
To sum up, while we made progress to shed light on the decision processes used by participants, we have not yet established a complete process model, which should be the goal for future research [159, 160].
Does it matter what matters for reidentification?
What are the implications of our studies for debates in cognitive sciences and other disciplines? Lay intuitions may be more prone to error than those of philosophers [100]—although experts’ authority may also be questionable, as their philosophical intuitions are partly a function of their personality [161]. Our participants’ endorsement of identity relations of an original with two non-identical persons violates the transitivity of identity. Yet this response pattern may simply show that our participants do not conceive of personal identity as strictly numerical, or that they have alternative conceptions of persons. Our results are in any case highly relevant for a descriptive analysis of people’s understanding of identity and their theories of survival. Further, Nozick [14] would not attribute the variance in people’s perspectives to errors or false everyday beliefs [162], but rather to the variance in closeness metrics legitimately deemed appropriate by different persons. Our findings are similarly relevant for cases in which scientists, philosophers, or marketers try to appeal directly to lay intuitions or common sense.
Philosophers and psychologists differ in their conceptualizations of intuitions [163], yet in our complex scenarios participants could not arrive at their answers without careful assessment. When appealing to the common sense of people both in theorizing and in legitimizing operationalizations, a researcher “should respect what ordinary people in fact say when asked—unless they are somehow led astray” (in [115], p. 216). Study 2 eliminated one way in which participants may have been led astray, by moving from a continuous to an all-or-nothing decision. Any appeal to general intuition should take into account both our main results and the interindividual variability demonstrated in both studies. Any attempt to measure the conceptualization of self or personal identity may be informed by both our positive and our negative findings.
Psychological research has analyzed psychopathological conditions that entail potential breaks in personal continuity and identity [164]. For example, patients with the Fregoli delusion are convinced that different people are in fact a single person appearing in a variety of disguises. Here, the recognition of the outward appearance is separated from the identification of the person. This disorder goes beyond prosopagnosia, or face blindness, where the perception of faces does not allow for identification of persons (see also [165]). Patients with Capgras delusion believe that a specific person, often a loved one, has been replaced by a duplicate who is indistinguishable from the original person. In cases of mirror misidentification, patients fail to recognize their own reflection and infer that the person in the mirror must be someone else [166]. These observations from clinical psychology indicate that the neural mechanisms of identification cannot be reduced to acts of perceptual recognition, and hint at the requisite capacities necessary for personal reidentification; furthermore, understanding ordinary reidentification processes might help to understand and locate their disruption.
As the introductory example shows, the importance and reach of identity questions are not limited to specialized academic discourse, even if not every instance is as dramatic as the hanging of Arnaud du Tilh. A survey of current debates outside philosophy referencing the personal identity literature creates the impression that many of Parfit’s [6] suggestions, examples and ideas are still in the process of being (re)discovered. Mott [167] explored Parfit’s suggestion that diminished personal connectedness might be a reason for statutes of limitations (p. 325), and provided evidence that desert of punishment and grounds for criticizing a person for past deeds are considered to diminish over time, which is partially explained by the reduction in closeness. A second debate is centered on the question of the validity of living wills after substantive changes to a person’s cognitive capabilities. For example, can a competent person impose values and interests on the future incompetent person or should the strength of advance directives grow weaker with the loss of closeness [21, 81, 168]? The incompetent person might, for example, derive unexpected pleasure and satisfaction under conditions the competent person did not foresee. Further, references to a future self might have a tremendous impact on ethical behavior [46], motivation, and goal-pursuit [169]; the sense of temporal persistence can motivate future-oriented self-regard and short-term sacrifices benefiting future outcomes [43, 44]. Without personal identity, it would be meaningless to make promises, grant ownership or the right to vote [79], or offer compensation [10, 12]; challenges to personal identity affect the institutions built upon it.
Disruptions of personal identity have been shown to severely impact people’s lives. Chandler and colleagues [61] presented impressive evidence of the connection between the inability to give an account of one’s identity and the risk of adolescent suicide, and how cultural continuity can moderate the elevation of suicide risk in vulnerable minority groups. This line of research raises the question or how one’s perspective on personal identity is shaped by the social environment and connects the concept to mental health. A diminished sense of self and the self’s stable existence is also deeply intertwined with borderline personality disorder [170]. Furthermore, challenges to personal identity can also emerge due to technological innovation. Notions of identity are fundamental in conceptualizing behavior in virtual environments [171] and have implications in law in connection with identity theft [172] or impersonation. Pascalev and colleagues [63] discussed how first suggestions for a medical head transplant procedure introduced questions of personal identity into neuroethics.
The gravity of these real-world examples goes well beyond that found in hypothetical thought experiments. The analysis of contrafactual scenarios has nevertheless paved the way for addressing real-world concerns and situations, whose connection to personal identity is discovered through analogy, created through technology, or bestowed by social institutions. Understanding how the concept is perceived and applied and how experimental puzzles of seemingly little direct relevance are tackled and solved can ultimately inform practitioners and theoreticians facing recurrent and novel situations with serious consequences.
The highest probability of reaching 90 years was found for those drinking 5– < 15 g alcohol/day; although not significant, the risk estimates also indicate to avoid binge drinking
Alcohol consumption in later life and reaching longevity: the Netherlands Cohort Study. Piet A van den Brandt, Lloyd Brandts. Age and Ageing, afaa003, February 9 2020. https://academic.oup.com/ageing/advance-article/doi/10.1093/ageing/afaa003/5730334
Abstract
Background: whether light-to-moderate alcohol intake is related to reduced mortality remains a subject of intense research and controversy. There are very few studies available on alcohol and reaching longevity.
Methods: we investigated the relationship of alcohol drinking characteristics with the probability to reach 90 years of age. Analyses were conducted using data from the Netherlands Cohort Study. Participants born in 1916–1917 (n = 7,807) completed a questionnaire in 1986 (age 68–70 years) and were followed up for vital status until the age of 90 years (2006–07). Multivariable Cox regression analyses with fixed follow-up time were based on 5,479 participants with complete data to calculate risk ratios (RRs) of reaching longevity (age 90 years).
Results: we found statistically significant positive associations between baseline alcohol intake and the probability of reaching 90 years in both men and women. Overall, the highest probability of reaching 90 was found in those consuming 5– < 15 g/d alcohol, with RR = 1.36 (95% CI, 1.20–1.55) when compared with abstainers. The exposure-response relationship was significantly non-linear in women, but not in men. Wine intake was positively associated with longevity (notably in women), whereas liquor was positively associated with longevity in men and inversely in women. Binge drinking pointed towards an inverse relationship with longevity. Alcohol intake was associated with longevity in those without and with a history of selected diseases.
Conclusions: the highest probability of reaching 90 years was found for those drinking 5– < 15 g alcohol/day. Although not significant, the risk estimates also indicate to avoid binge drinking.
Keywords: alcohol, longevity, aging, dose–response relationship, mortality, cohort studies, older people
Discussion
In this large prospective study, we found statistically significant positive associations between alcohol intake and the probability of reaching 90 years in both men and women. Overall, the highest probability was found in those consuming 5– < 15 g/d alcohol, which corresponds to 0.5–1.5 glass of alcoholic beverage per day. The exposure–response relationship was significantly non-linear in women, but not in men. Whereas the probability of longevity was decreasing in women with alcohol intakes above 15 g/d, it remained elevated at higher alcohol consumption levels in men. In beverage-specific analyses, wine intake was positively associated with longevity (notably in women), whereas liquor was positively associated with longevity in men and inversely in women. Binge drinking was not significantly associated with longevity, but the risk estimates indicate to avoid binge drinking. In subgroup analyses, alcohol intake was associated with longevity in those with or without a history of selected diseases.
Previous prospective studies on longevity from the US and France that reported on alcohol were rather limited (no alcohol focus) and found no significant associations using longevity cut-offs of 75 [12] and 90 years [13, 25]. However, higher alcohol intakes were seen in survivors compared to non-survivors [25], and in subsequent analyses (85+ years) of the Framingham Heart Study [26]. The Physicians Health Study amongst US male physicians (survival cut-off 90) reported small and non-significantly increased chances of longevity for various drinking categories compared to rarely/never alcohol drinkers, with no dose–response relationship [13]. The association between alcohol drinking and longevity was studied twice in the Honolulu Heart Program (HHP) amongst Japanese-American men using 85 years as longevity cut-off [10, 11]. Heavy alcohol intake, measured at baseline age 45–68 years, was significantly inversely related to longevity (OR = 0.63, for 3+ drinks/day versus drinking less) [10]. In the second analysis, moderate-heavy alcohol intake around 75 years was also significantly inversely related to longevity (OR = 0.66, for drinking >14.5 g/day versus less) [11]. The fact that the HHP study was conducted amongst men of Japanese ancestry may (partly) explain the more negative association of alcohol with longevity, and suggests a potential mechanism. It is known that East Asians are less efficient alcohol metabolizers due to a common loss-of-function variant of the ALDH2-gene, which decreases breakdown of acetaldehyde, the first, toxic alcohol metabolite [27]. It could be that those who nevertheless drink experience a higher mortality risk.
Overall, the results of previous longevity studies seem quite limited. Our detailed analyses show significantly positive associations between alcohol and longevity in both men and women, which is in agreement with the PHS [13]. Overall in men and women combined in the NLCS, the highest probability of reaching 90 was found in those consuming 5– < 15 g/d alcohol, with a HR of 1.36 compared to abstainers. Women experience higher blood alcohol concentrations than men of similar weight due to lower total body water [15]. Thus, adverse effects of higher alcohol intakes may appear earlier in women. This might explain the non-linear exposure–response relationship in women and not in men. We also found that wine intake was positively associated with longevity, whereas liquor was positively associated with longevity in men, and inversely in women. Before speculating on reasons for these beverage differences, future longevity studies are needed to replicate these sex-specific findings, with those on pattern and binge drinking. In mortality studies, there was no clear indication for sex differences [2, 5], and although beneficial associations with wine have been described for mortality, e.g. [2], this topic remains controversial.
As in observational studies on alcohol and mortality [1, 2, 8], studies on alcohol and longevity may be hampered by possible biases (selection and residual confounding biases). Here, selection bias can refer to abstainer bias (when the reference category of non-drinkers also includes sick quitters), the healthy drinker/survivor bias (when cohorts of older participants may be overrepresented by healthier drinkers who may have survived adverse effects of alcohol). Reverse causation may occur because health status may influence alcohol drinking [8], which could be addressed by restricting analyses to healthy people at baseline. Incomplete adjustment for confounding factors may lead to residual confounding. In our longevity analysis, we tried to address these possible biases by: (i) excluding ex-drinkers from the reference category; (ii) limiting analyses to stable drinkers and abstainers by taking alcohol consumption 5 years before baseline into account; (iii) restricting analyses to participants without prevalent diseases and (iv) adjusting for a large range of possible confounders with detailed information. These analysis strategies do not necessarily provide a full remedy against all possible biases [8], but these were the possibilities with the available data from our cohort. For example, we had no information on lifetime alcohol consumption or consumption on various ages during lifetime, so our analysis of past consumption was limited. After excluding ex-drinkers from the reference category, the analyses in the stable subgroup were essentially similar to what was seen overall. We also found that alcohol intake was associated with longevity in the subgroup without a history of selected diseases. Still, other diseases might have affected alcohol use or longevity. Residual confounding by socioeconomic status is also possible, because we only controlled for educational level.
It should be noted that the percentages of never drinkers were relatively high in the NLCS: 15% in men and 35% in women, making this common behaviour a logical reference category. These percentages were substantially higher than in other cohorts, e.g. 8% in male and 16% in female PLCO-participants [2], and 6% in male and 16% in female EPIC-participants [28]. Strengths of the NLCS are the prospective design and high completeness of follow-up, making information bias and selection bias due to differential follow-up unlikely. The validation study of the food frequency questionnaire has shown that it performs relatively well with respect to alcohol [19], but measurement error may still have attenuated associations. The lack of possibilities to update alcohol intake or other lifestyle data during follow-up may have resulted in some attenuated associations too. Our study was aimed at measuring alcohol intake at 68–70 years. Therefore, our study results are limited to alcohol drinking in later life; future longevity studies preferably include lifetime consumption. The alcohol measures in our study were not aimed to get an all-encompassing indication of risky drinking, like in the Alcohol Use Disorders Identification Test/AUDIT [29]. Our cut-off for binge drinking (>6 drinks per occasion) as used in the 1980s/1990s [29, 30] is somewhat higher than current cut-offs [29]. Because we were interested in the association of late life drinking with longevity, our study likely examined a resilient population that survived already until 68 years despite possible earlier risky drinking.
While older people perceive themselves as controlled responsible drinkers, according to a recent thematic synthesis of qualitative studies, they consider alcohol use often as important part of social occasions, and report that alcohol helps creating feelings of relaxation [31]. A possible beneficial effect of light-moderate alcohol intake on longevity (with inverted J-shaped dose-response on longevity) may also be related to hormesis [32, 33]. With higher consumption in older people, medication may be negatively affected by alcohol, and there is decreased physiological tolerance [34].
In conclusion, in this prospective study of men and women aged 68–70 years at baseline, we found the highest probability of reaching 90 years of age for those drinking 5– < 15 g alcohol/day. This does not necessarily mean that light-to-moderate drinking improves health. The estimated RR of 1.36 implies a modest absolute increase in this probability and should not be used as motivation to start drinking if one does not drink alcoholic beverages. Although no significant association was found, the risk estimates also indicate to avoid binge drinking.
Elected officials in eleven U.S. southern states: Framing the decision to remove Confederate symbols as good for business causes those officials to favor removing the Confederate flag from public spaces
Economic Interests Cause Elected Officials to Liberalize Their Racial Attitudes. Christian R. Grose, Jordan Carr Peterson. Political Research Quarterly, February 10, 2020. https://doi.org/10.1177/1065912919899725
Abstract: Do attitudes of elected officials toward racial issues change when the issues are portrayed as economic? Traditionally, scholars have presented Confederate symbols as primarily a racial issue: elites supporting their eradication from public life tend to emphasize the association of Confederate symbols with slavery and institutionalized racism, while those elected officials who oppose the removal of Confederate symbols often cite the heritage of white southerners. In addition to these racial explanations, we argue that there is an economic component underlying support for removal of Confederate symbols among political elites. Racial issues can also be economic issues, and framing a racial issue as an economic issue can change elite attitudes. In the case of removal of Confederate symbols, the presence of such imagery is considered harmful to business. Two survey experiments of elected officials in eleven U.S. southern states show that framing the decision to remove Confederate symbols as good for business causes those elected officials to favor removing the Confederate flag from public spaces. Elected officials can be susceptible to framing, just like regular citizens.
Keywords: American politics, race, ethnicity, and politics, experiments, political elites, framing, symbolic representation, policy
Abstract: Do attitudes of elected officials toward racial issues change when the issues are portrayed as economic? Traditionally, scholars have presented Confederate symbols as primarily a racial issue: elites supporting their eradication from public life tend to emphasize the association of Confederate symbols with slavery and institutionalized racism, while those elected officials who oppose the removal of Confederate symbols often cite the heritage of white southerners. In addition to these racial explanations, we argue that there is an economic component underlying support for removal of Confederate symbols among political elites. Racial issues can also be economic issues, and framing a racial issue as an economic issue can change elite attitudes. In the case of removal of Confederate symbols, the presence of such imagery is considered harmful to business. Two survey experiments of elected officials in eleven U.S. southern states show that framing the decision to remove Confederate symbols as good for business causes those elected officials to favor removing the Confederate flag from public spaces. Elected officials can be susceptible to framing, just like regular citizens.
Keywords: American politics, race, ethnicity, and politics, experiments, political elites, framing, symbolic representation, policy
Strong results! Overall relative risk of mortality of 1.0018! And data "cannot be made publicly available"... Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries
Strong results! Overall relative risk of mortality of 1.0018! And data "cannot be made publicly available"... "Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries." Ana M Vicedo-Cabrera et al. BMJ 2020; 368, February 10. https://doi.org/10.1136/bmj.m108
Data sharing: Data have been collected within the MCC (Multi-City Multi-Country) Collaborative Research Network (http://mccstudy.lshtm.ac.uk/) under a data sharing agreement and cannot be made publicly available. [...]
Abstract
Objective To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide.
Design Two stage time series analysis.
Setting 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network.
Population Deaths for all causes or for external causes only registered in each city within the study period.
Main outcome measures Daily total mortality (all or non-external causes only).
Results A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 µg/m3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 µg/m3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 µg/m3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively.
Conclusions Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies.
Data sharing: Data have been collected within the MCC (Multi-City Multi-Country) Collaborative Research Network (http://mccstudy.lshtm.ac.uk/) under a data sharing agreement and cannot be made publicly available. [...]
Abstract
Objective To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide.
Design Two stage time series analysis.
Setting 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network.
Population Deaths for all causes or for external causes only registered in each city within the study period.
Main outcome measures Daily total mortality (all or non-external causes only).
Results A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 µg/m3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 µg/m3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 µg/m3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively.
Conclusions Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies.
Online sexual activities: Men engage in solitary-arousal activities, women in partnered-arousal activities; teens are the highest users of mobile digital devices and potentially of on-line SAs
Exploring new measures of online sexual activities, device use, and gender differences. Véronique O. Bélanger Lejars, Charles H. Bélanger, Jamil Razmak. Computers in Human Behavior, February 13 2020, 106300. https://doi.org/10.1016/j.chb.2020.106300
Highlights
• Participants engage in OSA, particularly solitary-arousal-based-self-videos.
• Men engage in solitary-arousal activities, women in partnered-arousal activities.
• Computers are the preferred method for OSAs overall.
• Smartphone apps were overwhelmingly preferred in partnered-arousal activities.
• Teens are the highest users of mobile digital devices and potentially of OSA.
Abstract: Online sexual activities (OSA) are any sexual behaviours done using the Internet and are divided into non-arousal, partnered-arousal, and solitary-arousal activities. The means of accessing the Internet have extended past the traditional home computer and the rapid evolution of personal digital devices has led to a lag in the measurement of OSA. The current study’s aim is to explore a new measurement scale that considers the widespread use of personal digital devices and examines gender differences in OSA. Results show that the suggested scale is a reliable measurement of OSA. Women engaged in more partnered-arousal activities whereas men engaged in more solitary-arousal activities. Computer use was the preferred method for OSA overall but smartphone apps were the preferred method for partnered-arousal activities. Some implications for parents and educators, clinicians, and researchers as well as limitations inviting to further research are provided as OSA is an emerging but rapidly evolving field of investigation.
Highlights
• Participants engage in OSA, particularly solitary-arousal-based-self-videos.
• Men engage in solitary-arousal activities, women in partnered-arousal activities.
• Computers are the preferred method for OSAs overall.
• Smartphone apps were overwhelmingly preferred in partnered-arousal activities.
• Teens are the highest users of mobile digital devices and potentially of OSA.
Abstract: Online sexual activities (OSA) are any sexual behaviours done using the Internet and are divided into non-arousal, partnered-arousal, and solitary-arousal activities. The means of accessing the Internet have extended past the traditional home computer and the rapid evolution of personal digital devices has led to a lag in the measurement of OSA. The current study’s aim is to explore a new measurement scale that considers the widespread use of personal digital devices and examines gender differences in OSA. Results show that the suggested scale is a reliable measurement of OSA. Women engaged in more partnered-arousal activities whereas men engaged in more solitary-arousal activities. Computer use was the preferred method for OSA overall but smartphone apps were the preferred method for partnered-arousal activities. Some implications for parents and educators, clinicians, and researchers as well as limitations inviting to further research are provided as OSA is an emerging but rapidly evolving field of investigation.
Wednesday, February 12, 2020
Congenital amusia (tone deafness) is a lifelong musical disorder that affects 4% of the population (single estimate based on a single test from 1980); it is more 1.5pct of pop. and is highly heritable
Peretz, Isabelle, and Dominique T. Vuvan. 2020. “Prevalence of Congenital Amusia.” PsyArXiv. February 12. doi:10.1038/ejhg.2017.15
Abstract: Congenital amusia (commonly known as tone deafness) is a lifelong musical disorder that affects 4% of the population according to a single estimate based on a single test from 1980. Here we present the first large-based measure of prevalence with a sample of 20 000 participants, which does not rely on self-referral. On the basis of three objective tests and a questionnaire, we show that (a) the prevalence of congenital amusia is only 1.5%, with slightly more females than males, unlike other developmental disorders where males often predominate; (b) self-disclosure is a reliable index of congenital amusia, which suggests that congenital amusia is hereditary, with 46% first-degree relatives similarly affected; (c) the deficit is not attenuated by musical training and (d) it emerges in relative isolation from other cognitive disorder, except for spatial orientation problems. Hence, we suggest that congenital amusia is likely to result from genetic variations that affect musical abilities specifically.
Abstract: Congenital amusia (commonly known as tone deafness) is a lifelong musical disorder that affects 4% of the population according to a single estimate based on a single test from 1980. Here we present the first large-based measure of prevalence with a sample of 20 000 participants, which does not rely on self-referral. On the basis of three objective tests and a questionnaire, we show that (a) the prevalence of congenital amusia is only 1.5%, with slightly more females than males, unlike other developmental disorders where males often predominate; (b) self-disclosure is a reliable index of congenital amusia, which suggests that congenital amusia is hereditary, with 46% first-degree relatives similarly affected; (c) the deficit is not attenuated by musical training and (d) it emerges in relative isolation from other cognitive disorder, except for spatial orientation problems. Hence, we suggest that congenital amusia is likely to result from genetic variations that affect musical abilities specifically.
Domestic cats spontaneously discriminate between the number and size of potential prey in a way that can be interpreted as adaptive for a lone-hunting, obligate carnivore, and show complex levels of risk–reward analysis
Revisiting more or less: influence of numerosity and size on potential prey choice in the domestic cat. Jimena Chacha, Péter Szenczi, Daniel González, Sandra Martínez-Byer, Robyn Hudson & Oxána Bánszegi . Animal Cognition, Feb 12 2020. https://link.springer.com/article/10.1007/s10071-020-01351-w
Abstract: Quantity discrimination is of adaptive relevance in a wide range of contexts and across a wide range of species. Trained domestic cats can discriminate between different numbers of dots, and we have shown that they also spontaneously choose between different numbers and sizes of food balls. In the present study we performed two experiments with 24 adult cats to investigate spontaneous quantity discrimination in the more naturalistic context of potential predation. In Experiment 1 we presented each cat with the simultaneous choice between a different number of live prey (1 white mouse vs. 3 white mice), and in Experiment 2 with the simultaneous choice between live prey of different size (1 white mouse vs. 1 white rat). We repeated each experiment six times across 6 weeks, testing half the cats first in Experiment 1 and then in Experiment 2, and the other half in the reverse order. In Experiment 1 the cats more often chose the larger number of small prey (3 mice), and in Experiment 2, more often the small size prey (a mouse). They also showed repeatable individual differences in the choices which they made and in the performance of associated predation-like behaviours. We conclude that domestic cats spontaneously discriminate between the number and size of potential prey in a way that can be interpreted as adaptive for a lone-hunting, obligate carnivore, and show complex levels of risk–reward analysis.
Abstract: Quantity discrimination is of adaptive relevance in a wide range of contexts and across a wide range of species. Trained domestic cats can discriminate between different numbers of dots, and we have shown that they also spontaneously choose between different numbers and sizes of food balls. In the present study we performed two experiments with 24 adult cats to investigate spontaneous quantity discrimination in the more naturalistic context of potential predation. In Experiment 1 we presented each cat with the simultaneous choice between a different number of live prey (1 white mouse vs. 3 white mice), and in Experiment 2 with the simultaneous choice between live prey of different size (1 white mouse vs. 1 white rat). We repeated each experiment six times across 6 weeks, testing half the cats first in Experiment 1 and then in Experiment 2, and the other half in the reverse order. In Experiment 1 the cats more often chose the larger number of small prey (3 mice), and in Experiment 2, more often the small size prey (a mouse). They also showed repeatable individual differences in the choices which they made and in the performance of associated predation-like behaviours. We conclude that domestic cats spontaneously discriminate between the number and size of potential prey in a way that can be interpreted as adaptive for a lone-hunting, obligate carnivore, and show complex levels of risk–reward analysis.
Non-reproducible: Evidence that social network index is associated with gray matter volume from a data-driven investigation
No strong evidence that social network index is associated with gray matter volume from a data-driven investigation. Chujun Lin et al. Cortex, February 12 2020. https://doi.org/10.1016/j.cortex.2020.01.021
Abstract: Recent studies in adult humans have reported correlations between individual differences in people’s Social Network Index (SNI) and gray matter volume (GMV) across multiple regions of the brain. However, the cortical and subcortical loci identified are inconsistent across studies. These discrepancies might arise because different regions of interest were hypothesized and tested in different studies without controlling for multiple comparisons, and/or from insufficiently large sample sizes to fully protect against statistically unreliable findings. Here we took a data-driven approach in a pre-registered study to comprehensively investigate the relationship between SNI and GMV in every cortical and subcortical region, using three predictive modeling frameworks. We also included psychological predictors such as cognitive and emotional intelligence, personality, and mood. In a sample of healthy adults (n = 92), neither multivariate frameworks (e.g., ridge regression with cross-validation) nor univariate frameworks (e.g., univariate linear regression with cross-validation) showed a significant association between SNI and any GMV or psychological feature after multiple comparison corrections (all R-squared values ≤ 0.1). These results emphasize the importance of large sample sizes and hypothesis-driven studies to derive statistically reliable conclusions, and suggest that future meta-analyses will be needed to more accurately estimate the true effect sizes in this field.
Abstract: Recent studies in adult humans have reported correlations between individual differences in people’s Social Network Index (SNI) and gray matter volume (GMV) across multiple regions of the brain. However, the cortical and subcortical loci identified are inconsistent across studies. These discrepancies might arise because different regions of interest were hypothesized and tested in different studies without controlling for multiple comparisons, and/or from insufficiently large sample sizes to fully protect against statistically unreliable findings. Here we took a data-driven approach in a pre-registered study to comprehensively investigate the relationship between SNI and GMV in every cortical and subcortical region, using three predictive modeling frameworks. We also included psychological predictors such as cognitive and emotional intelligence, personality, and mood. In a sample of healthy adults (n = 92), neither multivariate frameworks (e.g., ridge regression with cross-validation) nor univariate frameworks (e.g., univariate linear regression with cross-validation) showed a significant association between SNI and any GMV or psychological feature after multiple comparison corrections (all R-squared values ≤ 0.1). These results emphasize the importance of large sample sizes and hypothesis-driven studies to derive statistically reliable conclusions, and suggest that future meta-analyses will be needed to more accurately estimate the true effect sizes in this field.
Racial slurs “reclaimed” by the targeted group convey affiliation rather than derogation; authors found that the intergroup use of reappropriated slurs was perceived quite positively by both White and Black individuals
Perceptions of Racial Slurs Used by Black Individuals Toward White Individuals: Derogation or Affiliation? Conor J. O’Dea, Donald A. Saucier. Journal of Language and Social Psychology, February 11, 2020. https://doi.org/10.1177/0261927X20904983
Abstract: Research suggests that racial slurs may be “reclaimed” by the targeted group to convey affiliation rather than derogation. Although it is most common in intragroup uses (e.g., “nigga” by a Black individual toward another Black individual), intergroup examples of slur reappropriation (e.g., “nigga” by a Black individual toward a White individual) are also common. However, majority and minority group members’ perceptions of intergroup slur reappropriation remain untested. We examined White (Study 1) and Black (Study 2) individuals’ perceptions of the reappropriated terms, “nigga” and “nigger” compared with a control term chosen to be a non-race-related, neutral term (“buddy”), a nonracial derogative term (“asshole”) and a White racial slur (“cracker”) used by a Black individual toward a White individual. We found that the intergroup use of reappropriated slurs was perceived quite positively by both White and Black individuals. Our findings have important implications for research on intergroup relations and the reappropriation of slurs.
Keywords: racial slurs, common in-group identity, social dominance theory, affiliation, derogation
Abstract: Research suggests that racial slurs may be “reclaimed” by the targeted group to convey affiliation rather than derogation. Although it is most common in intragroup uses (e.g., “nigga” by a Black individual toward another Black individual), intergroup examples of slur reappropriation (e.g., “nigga” by a Black individual toward a White individual) are also common. However, majority and minority group members’ perceptions of intergroup slur reappropriation remain untested. We examined White (Study 1) and Black (Study 2) individuals’ perceptions of the reappropriated terms, “nigga” and “nigger” compared with a control term chosen to be a non-race-related, neutral term (“buddy”), a nonracial derogative term (“asshole”) and a White racial slur (“cracker”) used by a Black individual toward a White individual. We found that the intergroup use of reappropriated slurs was perceived quite positively by both White and Black individuals. Our findings have important implications for research on intergroup relations and the reappropriation of slurs.
Keywords: racial slurs, common in-group identity, social dominance theory, affiliation, derogation
Calling into question that contagious yawning is a signal of empathy: No evidence of familiarity, gender or prosociality biases in dogs
Contagious yawning is not a signal of empathy: no evidence of
familiarity, gender or prosociality biases in dogs. Patrick Neilands et
al. Proceedings of the Royal Society B: Biological Sciences, Volume 287,
Issue 1920, February 5 2020. https://doi.org/10.1098/rspb.2019.2236
Abstract: Contagious yawning has been suggested to be a potential signal of empathy in non-human animals. However, few studies have been able to robustly test this claim. Here, we ran a Bayesian multilevel reanalysis of six studies of contagious yawning in dogs. This provided robust support for claims that contagious yawning is present in dogs, but found no evidence that dogs display either a familiarity or gender bias in contagious yawning, two predictions made by the contagious yawning–empathy hypothesis. Furthermore, in an experiment testing the prosociality bias, a novel prediction of the contagious yawning–empathy hypothesis, dogs did not yawn more in response to a prosocial demonstrator than to an antisocial demonstrator. As such, these strands of evidence suggest that contagious yawning, although present in dogs, is not mediated by empathetic mechanisms. This calls into question claims that contagious yawning is a signal of empathy in mammals.
It is important to acknowledge several caveats to our conclusions. Firstly, in both our reanalysis and experiment, the subjects were primarily responding to interspecific yawns from human demonstrators. While it is possible that dogs would respond differently to conspecific and interspecific yawning, there are several reasons to believe that this is not the case. Research in other species such as chimpanzees suggests that they respond similarly to conspecific and interspecific yawns [41], and, in our reanalysis, controlling for demonstrator type did not improve model fit. Nevertheless, more rigorous comparisons between how dogs respond to conspecific and interspecific yawning would be a useful future line of research. Secondly, it is important to note that the familiarity, gender, and prosociality biases are indirect measures of empathy [37]. As such, care needs to be taken in interpreting these biases and there remains substantial debate over how to do so. For example, it has been argued that both the tendency for children with ASD to be less prone to contagious yawning [83] and the familiarity bias [37,84,85] can be explained in terms of differences in attending to yawners rather than differences in empathetic response. Similarly, the gender bias reported in humans [29] is not straightforward to interpret and there is debate over whether it simply reflects a false positive in the literature [33,34]. By contrast, proponents of the contagious yawning–empathy hypothesis argue that the familiarity bias continues to be found even when controlling for differences in subjects' attention [40,41] and that the negative results for the gender bias in previous studies reflects methodological issues with prior experiments [34]. Furthermore, although alternative hypotheses such as the attentional hypothesis could explain the presence of a single bias such as the familiarity bias, only the contagious yawning–empathy hypothesis predicts the presence of all three biases. As such, testing for all three biases represents a powerful test of the contagious yawning–empathy hypothesis. Finally, searching for a novel signature, the prosociality bias, required a novel experimental methodology where dogs were exposed to a prosocial experimenter that interacted with them and an antisocial experimenter that ignored them. Previous work which used a similar methodology demonstrated that dogs do show a preference for the prosocial demonstrator [73], and so if the contagious yawning–empathy hypothesis is correct, dogs should have reacted with increased yawning to the prosocial demonstrator. However, further work would be useful in confirming the presence or absence of the prosociality bias in dogs and other species such as humans.
Research into contagious yawning has been dominated by the contagious yawning–empathy debate [37]. However, contagious yawning is an interesting phenomenon in its own right as its evolutionary roots and ultimate function remain a mystery [20]. Contagious yawning in animals may be the result of stress [54,57], an affiliation strategy [67], a means of communication [61], or a mechanism to improve collective vigilance within groups [37,68,69] rather than being related to empathy via a perception–action mechanism. Future research into contagious yawning should include a greater focus on testing between these and other hypotheses. For example, the affiliation hypothesis might predict that contagious yawning should be seen more frequently during reconciliation periods after conflict while the collective vigilance hypothesis posits that contagious yawning should increase in response to external disturbances [37,86]. However, it is important to note that these theories are not necessarily mutually exclusive [87] and that factors such as stress appear to influence yawning propensity in complex ways [88,89]. Additionally, an important next step is to consider evidence of contagious yawning outside of mammals. While there has been some work looking at contagious yawning in budgerigars [86,90] and tortoises [91], research has otherwise been sparse outside of the mammalian class.
Future research would benefit from systematically testing contagious yawning across multiple species. One barrier to such projects is that studying a range of different species often requires different experimental set-ups to make such testing feasible. There is a concern that such a range of methodological approaches may make cross-species and cross-study comparisons difficult, if not impossible [35,66]. However, our finding that the effect of treatment on yawning probabilities and rates remains stable when controlling for various aspects of study design suggests that the presence of contagious yawning is relatively robust to differences in experimental design. As such, while it is important to use broadly similar designs (for instance, comparing animals’ yawning rates when exposed to either a yawning demonstrator or control demonstrator), there could be considerable flexibility in other aspects of study design. For example, our results suggest that animals' yawning probabilities and rates to either live demonstrators or recorded demonstrators are comparable. Therefore, our findings suggest that more ambitious cross-species work can be carried out with confidence in the validity of the subsequent comparisons.
To conclude, our results provide robust support for the hypothesis that contagious yawning is found in dogs, the first non-human species of mammal where it has been clearly shown outside of chimpanzees. However, we found no evidence that dogs yawn more in response to either familiar human yawners compared to unfamiliar human yawners, or to prosocial human yawners compared to antisocial human yawners. Additionally, we found no evidence that female dogs were more likely to yawn in response to a yawning demonstrator than male dogs. As such, these findings cast doubt on the widespread assertion that contagious yawning is mediated by the same perception–action mechanism as empathy [1,6,35,41,58]. Instead, they support recent claims that there is no link between contagious yawning and empathetic processes [37,67] and underline the importance of developing more direct measures of empathy in non-human animals [37,92]. However, while our results suggest that researchers cannot rely on contagious yawning as a diagnostic signal of empathy, our additional findings that the effect of contagious yawning appears to be robust to variations in experimental methods suggest that cross-species comparisons may be a powerful way to disentangle the evolutionary roots of this behaviour.
Abstract: Contagious yawning has been suggested to be a potential signal of empathy in non-human animals. However, few studies have been able to robustly test this claim. Here, we ran a Bayesian multilevel reanalysis of six studies of contagious yawning in dogs. This provided robust support for claims that contagious yawning is present in dogs, but found no evidence that dogs display either a familiarity or gender bias in contagious yawning, two predictions made by the contagious yawning–empathy hypothesis. Furthermore, in an experiment testing the prosociality bias, a novel prediction of the contagious yawning–empathy hypothesis, dogs did not yawn more in response to a prosocial demonstrator than to an antisocial demonstrator. As such, these strands of evidence suggest that contagious yawning, although present in dogs, is not mediated by empathetic mechanisms. This calls into question claims that contagious yawning is a signal of empathy in mammals.
4. Discussion
By combining the data from six different studies, the resulting dataset is the largest used to date to examine the presence of contagious yawning in a non-human mammal. This allowed us to draw conclusions about the presence and absence of contagious yawning and the signatures predicted by the contagious yawning–empathy hypothesis with a greater level of certainty than by relying on individual studies alone. Our reanalysis shows that dogs do exhibit contagious yawning, showing higher probabilities and rates of yawning for yawning demonstrators compared to control demonstrators. This provides robust support for the claims that contagious yawning is present in dogs [35,49–51]. In order to test whether this contagious yawning is related to mechanisms underpinning empathy, we examined this dataset for evidence of the familiarity bias and gender bias. However, dogs in our reanalysis showed no evidence of either of these biases. Similarly, when we ran a novel experiment to look for a prosociality bias, we found that the dogs in our experiment were no more likely to yawn for prosocial demonstrators than antisocial demonstrators. Dogs, therefore, show no evidence for any of the familiarity, gender, or prosociality biases predicted by the contagious yawning–empathy hypothesis. This suggests that contagious yawning in dogs is not mediated by an empathy-related perception–action mechanism [52–54]. The presence of contagious yawning in non-human animals, therefore, cannot be assumed to be evidence for a perception–action mechanism shared between humans and other mammals, as has been previously proposed [1,35,41,58]. That is not to say that some non-human animals do not necessarily experience some form of empathy but that contagious yawning cannot be taken as a diagnostic signal for the presence of these empathetic processes. Furthermore, these results, alongside the arguments put forward by Massen & Gallup in their recent review [37], bring into question the validity of the contagious yawning–empathy hypothesis more broadly.It is important to acknowledge several caveats to our conclusions. Firstly, in both our reanalysis and experiment, the subjects were primarily responding to interspecific yawns from human demonstrators. While it is possible that dogs would respond differently to conspecific and interspecific yawning, there are several reasons to believe that this is not the case. Research in other species such as chimpanzees suggests that they respond similarly to conspecific and interspecific yawns [41], and, in our reanalysis, controlling for demonstrator type did not improve model fit. Nevertheless, more rigorous comparisons between how dogs respond to conspecific and interspecific yawning would be a useful future line of research. Secondly, it is important to note that the familiarity, gender, and prosociality biases are indirect measures of empathy [37]. As such, care needs to be taken in interpreting these biases and there remains substantial debate over how to do so. For example, it has been argued that both the tendency for children with ASD to be less prone to contagious yawning [83] and the familiarity bias [37,84,85] can be explained in terms of differences in attending to yawners rather than differences in empathetic response. Similarly, the gender bias reported in humans [29] is not straightforward to interpret and there is debate over whether it simply reflects a false positive in the literature [33,34]. By contrast, proponents of the contagious yawning–empathy hypothesis argue that the familiarity bias continues to be found even when controlling for differences in subjects' attention [40,41] and that the negative results for the gender bias in previous studies reflects methodological issues with prior experiments [34]. Furthermore, although alternative hypotheses such as the attentional hypothesis could explain the presence of a single bias such as the familiarity bias, only the contagious yawning–empathy hypothesis predicts the presence of all three biases. As such, testing for all three biases represents a powerful test of the contagious yawning–empathy hypothesis. Finally, searching for a novel signature, the prosociality bias, required a novel experimental methodology where dogs were exposed to a prosocial experimenter that interacted with them and an antisocial experimenter that ignored them. Previous work which used a similar methodology demonstrated that dogs do show a preference for the prosocial demonstrator [73], and so if the contagious yawning–empathy hypothesis is correct, dogs should have reacted with increased yawning to the prosocial demonstrator. However, further work would be useful in confirming the presence or absence of the prosociality bias in dogs and other species such as humans.
Research into contagious yawning has been dominated by the contagious yawning–empathy debate [37]. However, contagious yawning is an interesting phenomenon in its own right as its evolutionary roots and ultimate function remain a mystery [20]. Contagious yawning in animals may be the result of stress [54,57], an affiliation strategy [67], a means of communication [61], or a mechanism to improve collective vigilance within groups [37,68,69] rather than being related to empathy via a perception–action mechanism. Future research into contagious yawning should include a greater focus on testing between these and other hypotheses. For example, the affiliation hypothesis might predict that contagious yawning should be seen more frequently during reconciliation periods after conflict while the collective vigilance hypothesis posits that contagious yawning should increase in response to external disturbances [37,86]. However, it is important to note that these theories are not necessarily mutually exclusive [87] and that factors such as stress appear to influence yawning propensity in complex ways [88,89]. Additionally, an important next step is to consider evidence of contagious yawning outside of mammals. While there has been some work looking at contagious yawning in budgerigars [86,90] and tortoises [91], research has otherwise been sparse outside of the mammalian class.
Future research would benefit from systematically testing contagious yawning across multiple species. One barrier to such projects is that studying a range of different species often requires different experimental set-ups to make such testing feasible. There is a concern that such a range of methodological approaches may make cross-species and cross-study comparisons difficult, if not impossible [35,66]. However, our finding that the effect of treatment on yawning probabilities and rates remains stable when controlling for various aspects of study design suggests that the presence of contagious yawning is relatively robust to differences in experimental design. As such, while it is important to use broadly similar designs (for instance, comparing animals’ yawning rates when exposed to either a yawning demonstrator or control demonstrator), there could be considerable flexibility in other aspects of study design. For example, our results suggest that animals' yawning probabilities and rates to either live demonstrators or recorded demonstrators are comparable. Therefore, our findings suggest that more ambitious cross-species work can be carried out with confidence in the validity of the subsequent comparisons.
To conclude, our results provide robust support for the hypothesis that contagious yawning is found in dogs, the first non-human species of mammal where it has been clearly shown outside of chimpanzees. However, we found no evidence that dogs yawn more in response to either familiar human yawners compared to unfamiliar human yawners, or to prosocial human yawners compared to antisocial human yawners. Additionally, we found no evidence that female dogs were more likely to yawn in response to a yawning demonstrator than male dogs. As such, these findings cast doubt on the widespread assertion that contagious yawning is mediated by the same perception–action mechanism as empathy [1,6,35,41,58]. Instead, they support recent claims that there is no link between contagious yawning and empathetic processes [37,67] and underline the importance of developing more direct measures of empathy in non-human animals [37,92]. However, while our results suggest that researchers cannot rely on contagious yawning as a diagnostic signal of empathy, our additional findings that the effect of contagious yawning appears to be robust to variations in experimental methods suggest that cross-species comparisons may be a powerful way to disentangle the evolutionary roots of this behaviour.
Of what they thought were 4 important predictors of subjective well-being (marriage, employment, prosociality, & life meaning), marriage showed only very small effects, & employment had larger effects that peaked around age 50 years
Subjective
Well-Being Around the World: Trends and Predictors Across the Life
Span. Andrew T. Jebb. Psychological Science, February 11, 2020.
https://doi.org/10.1177/0956797619898826
Abstract: Using representative cross-sections from 166 nations (more than 1.7 million respondents), we examined differences in three measures of subjective well-being over the life span. Globally, and in the individual regions of the world, we found only very small differences in life satisfaction and negative affect. By contrast, decreases in positive affect were larger. We then examined four important predictors of subjective well-being and how their associations changed: marriage, employment, prosociality, and life meaning. These predictors were typically associated with higher subjective well-being over the life span in every world region. Marriage showed only very small associations for the three outcomes, whereas employment had larger effects that peaked around age 50 years. Prosociality had practically significant associations only with positive affect, and life meaning had strong, consistent associations with all subjective-well-being measures across regions and ages. These findings enhance our understanding of subjective-well-being patterns and what matters for subjective well-being across the life span.
Keywords: subjective well-being, cross-cultural, aging, life meaning, prosocial behavior
Abstract: Using representative cross-sections from 166 nations (more than 1.7 million respondents), we examined differences in three measures of subjective well-being over the life span. Globally, and in the individual regions of the world, we found only very small differences in life satisfaction and negative affect. By contrast, decreases in positive affect were larger. We then examined four important predictors of subjective well-being and how their associations changed: marriage, employment, prosociality, and life meaning. These predictors were typically associated with higher subjective well-being over the life span in every world region. Marriage showed only very small associations for the three outcomes, whereas employment had larger effects that peaked around age 50 years. Prosociality had practically significant associations only with positive affect, and life meaning had strong, consistent associations with all subjective-well-being measures across regions and ages. These findings enhance our understanding of subjective-well-being patterns and what matters for subjective well-being across the life span.
Keywords: subjective well-being, cross-cultural, aging, life meaning, prosocial behavior
You may be more original than you think: Predictable biases in self-assessment of originality
You may be more original than you think: Predictable biases in self-assessment of originality. Yael Sidi et al. Acta Psychologica, Volume 203, February 2020, 103002. https://doi.org/10.1016/j.actpsy.2019.103002
Highlights
• Self-judgments of originality are sensitive to the serial order effect.
• Originality judgments reveal under-estimation robustly and resiliently.
• People discriminate well between more and less original ideas.
• There is a double dissociation between actual originality and originality judgments.
Abstract: How accurate are individuals in judging the originality of their own ideas? Most metacognitive research has focused on well-defined tasks, such as learning, memory, and problem solving, providing limited insight into ill-defined tasks. The present study introduces a novel metacognitive self-judgment of originality, defined as assessments of the uniqueness of an idea in a given context. In three experiments, we examined the reliability, potential biases, and factors affecting originality judgments. Using an ideation task, designed to assess the ability to generate multiple divergent ideas, we show that people accurately acknowledge the serial order effect—judging later ideas as more original than earlier ideas. However, they systematically underestimate their ideas' originality. We employed a manipulation for affecting actual originality level, which did not affect originality judgments, and another one designed to affect originality judgments, which did not affect actual originality performance. This double dissociation between judgments and performance calls for future research to expose additional factors underlying originality judgments.
Highlights
• Self-judgments of originality are sensitive to the serial order effect.
• Originality judgments reveal under-estimation robustly and resiliently.
• People discriminate well between more and less original ideas.
• There is a double dissociation between actual originality and originality judgments.
Abstract: How accurate are individuals in judging the originality of their own ideas? Most metacognitive research has focused on well-defined tasks, such as learning, memory, and problem solving, providing limited insight into ill-defined tasks. The present study introduces a novel metacognitive self-judgment of originality, defined as assessments of the uniqueness of an idea in a given context. In three experiments, we examined the reliability, potential biases, and factors affecting originality judgments. Using an ideation task, designed to assess the ability to generate multiple divergent ideas, we show that people accurately acknowledge the serial order effect—judging later ideas as more original than earlier ideas. However, they systematically underestimate their ideas' originality. We employed a manipulation for affecting actual originality level, which did not affect originality judgments, and another one designed to affect originality judgments, which did not affect actual originality performance. This double dissociation between judgments and performance calls for future research to expose additional factors underlying originality judgments.
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