The former passersby prepare themselves for a possible encounter with a police officer, in which case they could lie and claim that their mask unnoticeably slipped down from its proper position

Dishonesty and mandatory mask wearing in the COVID-19 pandemic. Yossef Tobol, Erez Siniver, Gideon Yaniv. Economics Letters, October 8 2020, 109617. https://doi.org/10.1016/j.econlet.2020.109617

Rolf Degen's take: https://twitter.com/DegenRolf/status/1314231853839192067

Abstract: In an attempt to slow down the spread of the coronavirus, an increasing number of countries, including Israel, have made wearing masks mandatory for their citizens not just in close public places but also while waking in the streets. Failing to comply with this regulation entails a fine enforced by the police. Still, while many passengers do wear a mask that covers both their mouth and nose, others wear a mask improperly around their chin or neck or walk the streets wearing no mask at all. We speculate that the former passersby prepare themselves for a possible encounter with a police officer, in which case they could lie and claim that their mask unnoticeably slipped down from its proper position. The present paper reports the results of a field experiment designed to examine the hypothesis that, given the opportunity, passersby who wear their mask around their chin or neck are more likely to lie than those who wear no mask at all, although intuition may suggest otherwise Incentivizing passersby’s dishonesty with the Die-Under-the-Cup (DUCT) task, the experiment results support our hypothesis.

Keywords: COVID-19 pandemicDishonestyLyingDie-Under-the-Cup task

People were relatively modest and self-critical about their funniness; extraversion & openness to experience predicted rating one’s responses as funnier; women rated their responses as less funny

Silvia, Paul, Gil Greengross, Katherine N. Cotter, Alexander P. Christensen, and Jeffrey M. Gredlein. 2020. “If You’re Funny and You Know It: Personality, Gender, and People’s Ratings of Their Attempts at Humor.” PsyArXiv. October 8. doi:10.31234/osf.io/3fgrj

Rolf Degen's take: https://twitter.com/DegenRolf/status/1314221698871439362

Abstract: In seven studies (n = 1,133), adults tried to create funny ideas and then rated the funniness of their responses, which were also independently rated by judges. People were relatively modest and self-critical about their ideas. Extraversion (r = .12 [.07, .18], k =7) and openness to experience (r = .09 [.03, .15], k = 7) predicted rating one’s responses as funnier; women rated their responses as less funny (d = -.28 [-.37, -.19], k = 7). The within-person correlation between self and judge ratings was small but significant (r = .13 [.07, .19], k = 7), so people had some insight into their ideas’ funniness.

Labor markets characterized by anonymity, relatively homogeneous work, and flexibility: Gender pay gaps can arise despite the absence of overt discrimination, labor segregation, and inflexible work arrangements

Litman L, Robinson J, Rosen Z, Rosenzweig C, Waxman J, Bates LM (2020) The persistence of pay inequality: The gender pay gap in an anonymous online labor market. PLoS ONE 15(2): e0229383. https://doi.org/10.1371/journal.pone.0229383

Abstract: Studies of the gender pay gap are seldom able to simultaneously account for the range of alternative putative mechanisms underlying it. Using CloudResearch, an online microtask platform connecting employers to workers who perform research-related tasks, we examine whether gender pay discrepancies are still evident in a labor market characterized by anonymity, relatively homogeneous work, and flexibility. For 22,271 Mechanical Turk workers who participated in nearly 5 million tasks, we analyze hourly earnings by gender, controlling for key covariates which have been shown previously to lead to differential pay for men and women. On average, women’s hourly earnings were 10.5% lower than men’s. Several factors contributed to the gender pay gap, including the tendency for women to select tasks that have a lower advertised hourly pay. This study provides evidence that gender pay gaps can arise despite the absence of overt discrimination, labor segregation, and inflexible work arrangements, even after experience, education, and other human capital factors are controlled for. Findings highlight the need to examine other possible causes of the gender pay gap. Potential strategies for reducing the pay gap on online labor markets are also discussed.

Skew in reproductive success (RS) is common across many animal species; study compares Afrocolombians (serially monogamous ) and Emberá (monogamous Amerindians in Colombia)

The multinomial index: a robust measure of reproductive skew. Cody T. Ross, Adrian V. Jaeggi, Monique Borgerhoff Mulder, Jennifer E. Smith, Eric Alden Smith, Sergey Gavrilets and Paul L. Hooper. Proceedings of the Royal Society B: Biological Sciences, October 7 2020. https://doi.org/10.1098/rspb.2020.2025

Abstract: Inequality or skew in reproductive success (RS) is common across many animal species and is of long-standing interest to the study of social evolution. However, the measurement of inequality in RS in natural populations has been challenging because existing quantitative measures are highly sensitive to variation in group/sample size, mean RS, and age-structure. This makes comparisons across multiple groups and/or species vulnerable to statistical artefacts and hinders empirical and theoretical progress. Here, we present a new measure of reproductive skew, the multinomial index, M, that is unaffected by many of the structural biases affecting existing indices. M is analytically related to Nonacs’ binomial index, B, and comparably accounts for heterogeneity in age across individuals; in addition, M allows for the possibility of diminishing or even highly nonlinear RS returns to age. Unlike B, however, M is not biased by differences in sample/group size. To demonstrate the value of our index for cross-population comparisons, we conduct a reanalysis of male reproductive skew in 31 primate species. We show that a previously reported negative effect of group size on mating skew was an artefact of structural biases in existing skew measures, which inevitably decline with group size; this bias disappears when using M. Applying phylogenetically controlled, mixed-effects models to the same dataset, we identify key similarities and differences in the inferred within- and between-species predictors of reproductive skew across metrics. Finally, we provide an R package, SkewCalc, to estimate M from empirical data.

2. Skew in a comparative context

Biological populations can differ greatly in the level of inequality characterizing the distribution of reproduction across same-sexed individuals [8]. In humans, reproductive inequality often varies substantially among cultural groups [9], especially as a function of marriage system and material wealth inequality. This topic has been of keen interest to evolutionary minded economists and anthropologists [28,29,49,50], who argue that the coevolutionary rise of monogamy, reproductive levelling, and highly unequal agrarian-state social structures constitutes one of the most striking counter-examples to otherwise well-accepted fitness/utility-based models of reproductive decision-making, like the polygyny threshold model [51]. Resolution of this paradoxical empirical pattern may be explained by norms for reproductive levelling [52–55] that enhance food security, group functionality, and/or success in intergroup competition [56–58], norms for monogamous partnering [29,50,59–61], or the level of complementarity in returns to biparental investment in humans [61,62]. Tests of such predictions, however, require comparative datasets and unbiased skew measures.

Beyond humans, Johnstone [2] and Kutsukake & Nunn [8] argue that a large body of theory on reproductive skew predicts clear relationships between inequality in reproduction and various social, ecological, and genetic factors—including relatedness, ecological constraints on reproduction, and opportunities to suppress or control the reproductive activities of other individuals. Differences in reproductive skew are thus predicted to have wide-reaching consequences for the evolution of biological characteristics (e.g. ornamentation [63], and testes size [64]), as well as social and behavioural ones (e.g. stable group size [65], effective population size [48], male tenure length [1], sociality [66], and the patterning of violence [67] and aggression [68]). To effectively test such theory, however, cross-species or cross-genera comparisons are often needed, but they have also been relatively sparse (but see [1,8]).

In one of the widest-scale comparative studies of reproductive skew to date, Kutsukake & Nunn [8] investigate the cross-species patterning of reproductive skew in male primates as a function of a suite of covariates. The data here are strong: sex-specific reproductive behaviour has been well-studied across primate species, and primates possess the requisite variation in social systems, mating systems, and ecological setting needed to compare competing predictions [69]. However, even within a small clade like primates, estimating differences in reproductive skew across species introduces some unique challenges: differences in age-structure, group size, and mean reproductive rate can preclude statistical comparisons based on existing skew metrics. In §6, we show how biased skew metrics can confound inference in this comparative study and others like it. To remedy these issues, we introduce a new metric of reproductive skew—the multinomial index, M—that will facilitate wider-scale comparative research.

Participants showed greater concern for pain in close others than for their own pain, though this hyperaltruism was steeply discounted with increasing social distance

Social discounting of pain. Giles W. Story  Zeb Kurth‐Nelson  Molly Crockett  Ivo Vlaev  Ara Darzi  Raymond J. Dolan. Journal of the Experimental Analysis of Behavior, October 7 2020. https://doi.org/10.1002/jeab.631

Abstract: Impatience can be formalized as a delay discount rate, describing how the subjective value of reward decreases as it is delayed. By analogy, selfishness can be formalized as a social discount rate, representing how the subjective value of rewarding another person decreases with increasing social distance. Delay and social discount rates for reward are correlated across individuals. However no previous work has examined whether this relationship also holds for aversive outcomes. Neither has previous work described a functional form for social discounting of pain in humans. This is a pertinent question, since preferences over aversive outcomes formally diverge from those for reward. We addressed this issue in an experiment in which healthy adult participants (N = 67) chose the timing and intensity of hypothetical pain for themselves and others. In keeping with previous studies, participants showed a strong preference for immediate over delayed pain. Participants showed greater concern for pain in close others than for their own pain, though this hyperaltruism was steeply discounted with increasing social distance. Impatience for pain and social discounting of pain were weakly correlated across individuals. Our results extend a link between impatience and selfishness to the aversive domain.

Discussion

Here we examined for the first time the relationship between the evaluation of one's own future pain and a sensitivity to pain in others, and whether altruistic responses to another's pain depend on the social distance of the other person. We find support for two novel findings. Firstly, people show greater concern for pain in close others than for their own pain, though this hyperaltruism is steeply discounted (diminishes) with increasing social distance. Secondly, we find a correlation between dread and social discounting, such that people who more strongly prefer immediate pain show steeper social discounting of pain, and thereby tend to be less altruistic overall. In keeping with previous findings, participants chose to speed up the delivery of pain both for themselves or others, even if this entailed an increased intensity of the pain, consistent with an effect of dread (Badia et al., 1966; Berns et al., 2006; Cook & Barnes, 1964; Hare, 1966a; Loewenstein, 1987; Story et al., 2013).

Social Discounting of Pain versus Money

Social discounting is consistent with evolutionary notions of kin altruism, which proposes that altruism towards related others carries an evolutionary advantage (Curry et al., 2013; Madsen et al., 2007; Schaub, 1996). Our finding of social discounting for pain extends previous findings of hyperaltruism towards close others for money (Rachlin & Jones, 2008), whereby some people prefer to assign a hypothetical monetary reward ($75) to their closest friend or relative (Person #1) than to receive a larger sum themselves (e.g. $80). Rachlin and Jones (2008) note that hyperaltruistic behavior is irrational in the monetary context, since participants could take the $80 for themselves and give it to Person #1. The same authors speculated that, in addition to wishing to signal their closeness to Person #1, people may have chosen the hyper‐generous option due to an implicit cost of having to transfer money, or as a self‐control device to prevent them from keeping the money for themselves. That we find hyperaltruism for close others for painful outcomes, which are nontransferrable, supports a more intrinsic charitable motive, in keeping with kin altruism.

We show support for a model of social discounting in which the net degree of altruistic behavior depends on both the degree of discounting over social distance (Ksoc) and an additional ‘altruism factor’ (θ) that is independent of social distance. Those with a high altruism factor and low social discounting (high θ, low Ksoc) would be expected to show charitable or caring behavior even towards distant others, for instance victims of war or famine in other countries. By contrast, those with a high altruism factor but steep social discounting (high θ, high Ksoc) would be expected to be protective of close kin, but to engage in little altruistic behavior directed outside of their social circle. These categories appear to have high face validity. A future line of investigation might be to compare these parameters for pain with those for money. Existing studies directly comparing generosity for pain and money demonstrate more charitable behavior with painful outcomes (Davis et al., 2011; Story et al., 2015), however to our knowledge no studies have examined this across social distance to test whether the effects are attributable to higher θ or lower Ksoc.

Applied Social Discounting of Pain

Further research is also required to establish how social discounting of pain relates to real‐world behavior, either charitable or antisocial. Existing work has linked social discounting of money to a range of real‐world behavior. A recent study has demonstrated lower social discounting of reward in extraordinarily altruistic people who have donated a kidney to a stranger (Vekaria et al., 2017), while steeper social discounting has been demonstrated among boys with externalizing (antisocial) behavioral problems (Sharp et al., 2011). Further applied work in this vein might also examine aversive, as well as monetary, outcomes. The current study illustrates that such preferences can be readily elicited using hypothetical painful scenarios.

Other authors have examined the effect of state‐based changes on the social discount curve for reward. Some such models have also examined the effects on the numerator term in the social discount model, namely, θ. For example, Wu et al. (2019) showed that testosterone administration in males increased social discounting for distant others, but had no effect on generosity towards close others. Strikingly, Margittai et al. (2015) showed that experimentally induced psychosocial stress appeared to have the reverse effect. Stress increased the numerator term, but had no effect on the social discount factor, manifest as greater generosity towards close, but not distant, others; a follow on study (Margittai et al., 2018) demonstrated that oral administration of hydrocortisone had the same effect. Further work is needed to investigate influences on the numerator term, in particular to disentangle effects of the instantaneous utility term from the effect of θ, since these enter multiplicatively into the numerator. Painful stimuli, which allow the form of instantaneous utility to be elicited directly using willingness to pay, offer a route to achieving this.

Positive Correlation between Dread and Social Discounting of Pain

Previous work suggests that the ability to wait for future rewards and the ability to understand the mental states of others are linked. For instance, temporal discounting for reward and altruistic behavior have been shown to be correlated across individuals (Curry et al., 2008; Rachlin & Jones, 2008), and both are impaired in Borderline Personality Disorder (Bateman & Fonagy, 2004). Along these lines a tendency to expedite pain so as to mitigate dread might be conceptualized as a future‐oriented behavior, akin to showing altruism towards one's future self. Indeed, both dread and altruism for pain have been shown to relate to the strength of physiological response to imagined pain: People who show greater anticipatory brain responses to pain are more likely to expedite pain rather than delay it (Berns et al., 2006), and people who show greater skin conductance responses to pain in others are more likely to choose to relieve another's pain (Hein et al., 2011). In keeping with this idea, people with higher trait psychopathy have been shown to be less likely to choose to expedite their own impending pain (Hare, 1966b) and show diminished physiological responses to the anticipation of pain in others (Caes et al., 2012). By this reasoning dread might be associated with lower social discounting of pain. Strikingly however, and contrary to our prediction, we found evidence that ‘higher dreaders’ showed steeper social discounting for pain.

Our data do not permit firm conclusions regarding the reasons for this correlation. However, a possible interpretation is that choice of sooner pain represents more a generic form of impatience than previously thought. We found that preference for sooner pain was best accounted for in terms of waiting cost that scaled with delay, but not with pain intensity. This finding is difficult to reconcile with previous models of dread, which focus on the aversive anticipation of pain, a quantity that would be expected to scale with pain intensity. Imagine for instance that you are contemplating either a trivially painful routine dental check‐up or a considerably more painful dental procedure. Our results suggest that the overall disvalue of the very painful procedure would still be greater than the routine check‐up but that the effect of delay on the disvalue of each would be identical.

The superior fit of a nonscaled model suggests that choices to expedite pain might not solely result from a desire to minimize the anticipation of pain, so much as a desire to reduce a generic cost associated with waiting. Notably reframing dread as impatience does not require any change to the form of our model, since the model does not specify the processes underlying a tendency to expedite pain. It is possible that a similar impatience term also contributes to discounting of reward (see for example Gonçalves & Silva, 2015). Such a reframing would make the observed correlation between impatience for pain and social discounting congruent with the correlation between delay discounting and social discounting seen for reward. There follows a strong prediction that impatience for pain and for reward ought to be correlated, indicating an important direction for further research.

Interactions between Dread and Social Discounting of Pain

A further interesting direction for future work concerns how delay and social discounting of pain interact. A pertinent question, for example, is whether effects of dread and social discounting are multiplicative or whether dread is revealed differently when choosing for others. Here we found that a preference for sooner pain was equivalent whether participants chose regarding their own pain, or that of another person at social distance #50. Notably however, in social discounting choices the mean participant showed neither marked social discounting nor hyperaltruism for a person at social distance #50, therefore further exploration is required to establish whether dread interacts with social discounting effects across a range of social distances. We have examined this in an additional study, submitted to this journal, in which we also elicit choices across both domains, for example pain for oneself now, versus for another person in the future, and vice versa (Story et al., 2020).

Factors in the Valuation of Future Pain

The model described here is challenged to disentangle the effects of discounting and dread within a given individual. We are grateful to a reviewer for the suggestion that measuring temporal preferences for past as well as future pain might offer a means to parse the two effects. Prior research has shown temporal discounting of past events to be lawful and also hyperbolic in form (e.g., Yi et al., 2006). Since dread presumably is not contained within events in the past, measuring discounting of past painful events could help to isolate the contribution of dread.

Finally, there are plausible reasons why choices to expedite pain might depend on factors other than dread of pain. Firstly, in many real‐world situations people choose to endure pain or discomfort so as to obtain an associated reward, for example having an immunization to prevent the possibility of illness, doing exercise to improve overall wellbeing, or working to earn a wage. If the rewards accrue at approximately the same time as the pain and outweigh its disvalue, then discounting of the net benefit could motivate speeding‐up the pain–reward combination. Secondly, it is often the case that painful experiences tend to get worse over time, making it rational to face them sooner: For instance in the real world the timing of a dental appointment might be brought forward to relieve worsening dental pain. Although our scenarios attempt to control for these factors, these prior assumptions may nevertheless influence people's experimental choices. Further experimental work is required to disentangle these possibilites. 

We argue that neural representations of memories are best thought of as spatially transformed versions of perceptual representations

Transforming the Concept of Memory Reactivation. Serra E. Favila, Hongmi Lee, Brice A. Kuhl. Trends in Neurosciences, October 8 2020. https://doi.org/10.1016/j.tins.2020.09.006

Highlights

.  A foundational finding in the field of memory is that content-sensitive patterns of neural activity expressed during perceptual experiences are re-expressed when experiences are remembered, a phenomenon termed reactivation. However, reactivation obscures key differences in how perceptual events and memories are represented in the brain.

.  Recent findings suggest systematic, spatial transformations of content-sensitive neural activity patterns from perception to memory retrieval. These transformations occur within sensory cortex and from sensory cortex to frontoparietal cortex.

.  We consider why spatial transformations occur and identify critical questions to be addressed in future research. Understanding the ways in which memory representations differ from perceptual representations will critically inform theoretical accounts of memory and will help clarify how the brain recreates the past.

Abstract: Reactivation refers to the phenomenon wherein patterns of neural activity expressed during perceptual experience are re-expressed at a later time, a putative neural marker of memory. Reactivation of perceptual content has been observed across many cortical areas and correlates with objective and subjective expressions of memory in humans. However, because reactivation emphasizes similarities between perceptual and memory-based representations, it obscures differences in how perceptual events and memories are represented. Here, we highlight recent evidence of systematic differences in how (and where) perceptual events and memories are represented in the brain. We argue that neural representations of memories are best thought of as spatially transformed versions of perceptual representations. We consider why spatial transformations occur and identify critical questions for future research.

Keywords: episodic memoryreactivationreinstatementmemory transformationsensory cortexfrontoparietal cortex

Outstanding Questions

To what extent do changes in information content account for spatial transformation from perception to retrieval? Are certain stimulus features that are present during perception systematically lost or distorted in memory? Do memory representations gain information that is absent or weakly present during perception through integration with other memories or existing knowledge structures (schemas)?

What determines the relative degree of neural reactivation versus transformation across brain regions observed during memory retrieval? For example, is greater transformation observed when memory tasks promote conceptual processing at retrieval? Conversely, is relatively greater reactivation in sensory areas observed when memory tasks promote perceptual processing? Does the relative degree of reactivation versus transformation depend on whether memory tasks involve recall versus recognition judgments? Do reactivation and transformation trade-off or are they independent?

Does the degree of transformation across brain regions depend on the temporal lag between perception and memory retrieval? Transformation potentially occurs in working memory paradigms with delays on the order of seconds, yet there is also considerable work documenting consolidation-related transformations at timescales of hours to years. What are the similarities and differences between transformations that occur across these vastly different timescales?

What is the relationship between transformation within sensory areas and transformation from sensory to frontoparietal regions? These two forms of transformation have been studied separately to date and it is thus unclear whether they are related and, if so, how. Notably, the frontoparietal and sensory regions that exhibit biases toward memory-based representations are functionally connected with the hippocampus. To what extent can connectivity with the hippocampus explain both sets of findings?

The association between the Big Five personality traits and smartphone use disorder: A meta-analysis

The association between the Big Five personality traits and smartphone use disorder: A meta-analysis. Davide Marengo et al. Journal of Behavioral Addictions, Oct 3 2020. https://doi.org/10.1556/2006.2020.00069

Abstract

Background and aims: Personality is one of the most frequently investigated variables to shed light on the putatively addictive use of the smartphone. By investigating associations between personality and individual differences in addictive smartphone use, researchers aim to understand if some personality traits predispose technology users to develop addictive behaviors. Here, based on existing empirical literature, we aimed at determining the strength of associations between Big Five personality traits and smartphone use disorder (SmUD) by a meta-analytic approach.

Method: For each Big Five personality trait, we performed a meta-analysis of correlations representing their association with SmUD. We also investigated possible publication bias and the moderating effects of age, gender, nationality, length of personality assessments, and time of publication.

Results: We found n = 26 eligible studies. In line with both the Interaction of Person-Affect-Cognition-Execution (I-PACE) model and the framework on problematic mobile-phone use by Billieux, we observed a positive association between Neuroticism and SmUD (r = 0.25), while the association between Extraversion and SmUD was not significant. Partially in line with the aforementioned theoretical frameworks, Conscientiousness was negatively associated with SmUD (r = −0.16). Remaining traits showed smaller associations. No significant publication bias emerged. Moderator analyses showed that time of publication moderated the link between Conscientiousness and SmUD. Moreover, Agreeableness and Conscientiousness showed a heightened inverse association with SmUD among older samples.

Conclusions: The present meta-analysis provides robust empirical evidence that Big Five personality traits can help to understand individual differences in SmUD, supporting the usefulness of their assessment when planning and targeting interventions aimed at at-risk individuals.

Discussion

The aim of the present work was to perform a meta-analysis of studies investigating the link between personality and SmUD. In light of available theories on SmUD it has been proposed that from the Big Five of personality, in particular Neuroticism should be positively related to SmUD severity. This association could indeed be observed (r = 0.25) giving support for Billieux's (2012) idea of an existing relationship assurance pathway. In this realm, individuals with higher scores on Neuroticism are more likely to develop higher tendencies towards SmUD due to seeking reaffirmation of being part of a social group via excessively checking social media apps, etc. (e.g., Marengo, Poletti, & Settanni, 2020). In fact, recent work has supported the relationship between greater levels of excessive reassurance seeking and SmUD severity (Elhai et al., 2020).

The second strongest associations among the Big Five personality traits was an inverse link between Conscientiousness and SmUD severity (r = −0.16). Such an association was not discussed in the work by Billieux (2012), but appears in the I-PACE model by Brand et al. (2016). In general, we believe such an inverse association to be a good fit with the large body of substance use disorder literature mentioning that individuals with low self-regulation abilities (see also links with low self-directedness out of Cloninger's biosocial theory of personality; Cloninger, 1994) are prone to develop higher addictive tendencies in many areas (Sariyska et al., 2014; Terracciano, Löckenhoff, Crum, Bienvenu, & Costa, 2008). Not surprisingly, low Conscientiousness has also been linked to lower health behavior (Bogg & Roberts, 2004). We believe that low Conscientiousness did not appear to be of relevance in Billieux's framework, because such an association has appeared only recently in the literature, due to smartphones probably having developed into more “addictive” devices over time, given the many social media and Freemium games available (Montag, Lachmann, et al., 2019). This idea is supported by our meta-analysis, showing that such Conscientiousness–SmUD associations have been stronger in recent years compared to what has been published in the early years of the smartphone era.

As expected from the model by Billieux (2012), Extraversion was not linked to SmUD in our meta-analysis. Therefore, fulfillment of the urge to communicate and socialize with other individuals via the smartphone (and the respective applications) may not result in addictive behavior related to the smartphone, hence, SmUD. Therefore, social use of the smartphone seems not to contribute to SmUD (Elhai, Hall, et al., 2017; Elhai, Levine, et al., 2017). As regards the Agreeableness and Openness traits, overall associations with SmUD were negative, but small-sized.

The present study also investigated gender- and age-related differences in the association between personality and SmUD. We did not find indicators of gender differences in the association between personality and SmUD. Regarding age, we found that the negative associations between SmUD and Conscientiousness as well as Agreeableness were stronger in samples including older adults, when compared to samples of adolescents and young adults. These findings may be understood in light of known age-related changes in these personality traits (e.g., both traits are known to be higher among older adults when compared to young adults; Allemand, Zimprich, & Hendriks, 2008; Donnellan & Lucas, 2008), and personal responsibilities – e.g., work and family responsibilities. Because individuals high on Conscientiousness and Agreeableness are more likely to use problem-focused and social-support coping strategies when dealing with daily stressors (Penley & Tomaka, 2002), they may be less likely to use technology (e.g., smartphones) as a form of avoidance strategy (Busch, P. A., & McCarthy, 2020). As individuals enter adulthood, and responsibilities increase, these traits may play a key role in helping them deal more successfully with stress (for such personality changes see Bleidorn, Hopwood, & Lucas, 2018), and ultimately protect them from developing SmUD.

The present meta-analysis also provided us with the opportunity to investigate potential publication bias in the literature. We failed to find consistent evidence of publication bias for any of the Big Five–SmUD associations. In sum, publication bias does not play a role in the present work. Additionally, from a psychometric point of view, we could not find significant evidence that length of personality assessment affected the strength of association between personality and SmUD.

At the same time, by taking a broad look at existing studies exploring the association between personality and SmUD, the present study was able to highlight existing limitations in the current literature. Our biggest concerns relate to the scarcity of studies recruiting representative samples, as the majority of the studies surveyed in this manuscript employed convenience samples. Moreover, there appears to be an overrepresentation of studies performed on samples of university students, typically showing an overrepresentation of women. For this reason, generalizability of results to the general population appears limited. Finally, most of the selected studies were implemented in English-speaking or European countries, while studies from other regional and cultural areas were scant, suggesting the need for increased diversity in this research area. This is particularly important given existing known cultural differences in the distribution of personality traits (e.g., Neuroticism, Lynn & Martin, 1995; Openness, Schmitt, Allik, McCrae, & Benet-Martínez, 2007), and their association with health-related outcomes, potentially including SmUD.

Limitations and directions for future research

The present work has several limitations. First of all, the present meta-analysis investigated cross-sectional studies. For this reason, it is not clear whether certain personality traits actually result in higher or lower SmUD, or whether such individual differences in personality are a result of the addictive smartphone use. Both directions of effects are possible. For example, spending an increasing amount of time on the smartphone most likely leads to neglecting other duties, e.g., work tasks, which might also result in a less conscientious self-description. Nevertheless, personality is rather stable (Edmonds, Jackson, Fayard, & Roberts, 2008) (but see for recent evidence how personality changes due to critical life events in Bleidorn et al. (2018)) and in line with theory (Billieux, 2012; Brand et al., 2016), we believe the former explanation to be true (i.e., individual differences in personality result in higher or lower SmUD). Still, it must be acknowledged that also in the I-PACE model feedback loops are included, which suggest an effect (not only from personality to SmUD but also) from SmUD on personality. In conclusion, future research should consider adopting a longitudinal approach, as this would help clarify the directions of emerging links between personality and SmUD. A second limitation is the focus of our meta-analysis on the Big Five personality traits. Although the Big Five are the most widely studied traits in the literature dealing with SmUD, a focus on other personality traits can also be important. For example, Billieux (2012) mentioned the relevance of the impulsivity trait, which is not covered in the present work. In detail, Billieux (2012) proposes an impulsive pathway describing individuals with low self-regulation abilities, and heightened risk behavior in the context of smartphones such as using the phone while driving. Another limitation concerns our inability to determine the prevalence of smartphone use in the samples of some of the studies published in early days of the smartphone era, which may have included individuals currently using mobile phones with limited Internet capabilities (i.e., mobile phones using GSM technology). Findings concerning the effect of time of publication on the association between personality and SmUD should be considered in light of this limitation.

Finally, the relatively small number of studies surveyed here limited our ability to detect small-sized moderation effects, leading to low statistical power when performing meta-regressions. As availability of newer studies will increase, the ability to detect these effects will improve. In particular, as noted above, there appears to be a need for more studies performed on samples including a more balanced representation of gender and age groups. Lack of representative samples also represents an important limitation of existing literature, limiting generalizability of results to the general population.

Male (vs female) students in single-sex environments preferred more masculinized (vs feminized) female (vs male) faces than their peers in mixed-sex environments

Individual differences in preferences for sexual dimorphism in faces among Chinese adolescents in single-sex and mixed-sex environments. Ruyue Tana, Lijun Zheng. Personality and Individual Differences, Volume 153, January 15 2020, 109648. https://doi.org/10.1016/j.paid.2019.109648

Abstract: Research indicates that people often show a preference for familiar faces, and frequent exposure to a particular type of face can lead to the development of a preference for faces with similar features. Adolescents in single-sex environments are more likely to be exposed to same-sex faces and less likely to view faces of the opposite sex. This study aimed to examine whether the effects of gendered environments on facial feature preferences exist in a Chinese cultural context. We examined individual differences in preferences for sexual dimorphism in faces among Chinese adolescents in single-sex and mixed-sex environments (N = 1431 mean age = 18.1). We found that male students in single-sex environments preferred more masculinized female faces than their peers in mixed-sex environments. Furthermore, female students in single-sex environments preferred more feminized male faces than their peers in mixed-sex environments. There were no significant differences in preferences for same-sex faces between participants in single-sex and mixed-sex environments for both male and female students. These results provide cross-cultural evidence that frequent exposure to certain types of faces can influence people's preferences regarding sexual dimorphism in facial features. The findings indicated the effect of gendered environments on mating preferences in older adolescents.

Keywords: Facial masculinitySingle-sex environmentSexual dimorphismVisual adaptionAdolescents

Rolf Degen summarizing... It may well be that Sigmund Freud stumbled upon universal, evolutionarily driven patterns of infant development, into which he mistakenly read the drama of the Oedipus complex

Türkarslan, Kutlu K. 2020. “It Is About Siblings, Not Sex: Oedipus Complex as an Expression of Parent-offspring Conflict.” PsyArXiv. October 7. doi:10.31234/osf.io/h8bpj

Abstract: Being Freud’s most famous contribution to psychoanalysis, the Oedipus complex is still a topic of heated interest. It has been disputed in many different disciplines ranging from anthropology to biology. This review was aimed to explain the phenomenon of the Oedipus complex in terms of parent-offspring conflict, sibling competition, and infanticide. All of these evolutionary biological concepts or their combination could conceive specific relational settings that may be mistakenly regarded as comprising the Freudian Oedipus complex by external observers. Furthermore, the propositions regarding the adaptive function of the Oedipus complex in terms of sexual imprinting and mate modeling are not robust and convincing. In this article, the author asserts while the Freudian Oedipus complex covers only the sex-contingent representations of parent-offspring conflict, the parent-offspring conflict may account for both sex-contingent and non-sex-contingent conflicts between the parents and the offspring. In light of this hypotheses, related literature and suggestions for further studies were discussed.

Well-being: Studies results seem to converge on a heritability estimate of about 40 to 50%

Van de Weijer, Margot, Lianne de Vries, and Meike Bartels. 2020. “Happiness and Wellbeing; the Value and Findings from Genetic Studies.” PsyArXiv. October 7. doi:10.31234/osf.io/zvu8j

Rolf Degen's take: https://twitter.com/DegenRolf/status/1313764455319298049

Abstract: In light of major global trends (e.g., rise of ageing populations, increasing longevity, decreasing birth rates), maintaining, facilitating, and building well-being (WB) is crucial, but also becomes increasingly complex and demanding. Over the past decade, twin studies have helped us get better insight into the extent to which genes and environments contribute to individual differences in well-being. Our knowledge about these genetic and environmental factors is continuingly growing with studies on well-being related phenotypes, extensions of twin studies, molecular genetic studies, and environmental studies. In this chapter, we provide an overview of past, present, and future directions of behavioural genetic research on well-being, happiness, and related phenotypes.

Work from a more diverse array of societies suggests there may be important variation in how much people rely on mental states, with people in some societies judging accidental harms just as harshly as intentional ones

Kinship intensity and the use of mental states in moral judgment across societies. Cameron M. Curtin et al. Evolution and Human Behavior, Volume 41, Issue 5, September 2020, Pages 415-429. https://doi.org/10.1016/j.evolhumbehav.2020.07.002. Ungated: https://henrich.fas.harvard.edu/files/henrich/files/curtin_et_al_2020_accepted_manuscript_with_supplement.pdf

Abstract: Decades of research conducted in Western, Educated, Industrialized, Rich, & Democratic (WEIRD) societies have led many scholars to conclude that the use of mental states in moral judgment is a human cognitive universal, perhaps an adaptive strategy for selecting optimal social partners from a large pool of candidates. However, recent work from a more diverse array of societies suggests there may be important variation in how much people rely on mental states, with people in some societies judging accidental harms just as harshly as intentional ones. To explain this variation, we develop and test a novel cultural evolutionary theory proposing that the intensity of kin-based institutions will favor less attention to mental states when judging moral violations. First, to better illuminate the historical distribution of the use of intentions in moral judgment, we code and analyze anthropological observations from the Human Area Relations Files. This analysis shows that notions of strict liability—wherein the role for mental states is reduced—were common across diverse societies around the globe. Then, by expanding an existing vignette-based experimental dataset containing observations from 321 people in a diverse sample of 10 societies, we show that the intensity of a society’s kin-based institutions can explain a substantial portion of the population-level variation in people’s reliance on intentions in three different kinds of moral judgments. Together, these lines of evidence suggest that people’s use of mental states has coevolved culturally to fit their local kin-based institutions. We suggest that although reliance on mental states has likely been a feature of moral judgment in human communities over historical and evolutionary time, the relational fluidity and weak kin ties of today’s WEIRD societies position these populations’ psychology at the extreme end of the global and historical spectrum.

Keywords: Moral judgment, mental states, theory of mind, kinship intensity, cultural evolution, WEIRD

Feedback Between Psychological Science and Policy in the Context of Same-Sex Couples

Feedback Between Psychological Science and Policy in the Context of Same-Sex Couples. Adam W. Fingerhut, David M. Frost. Policy Insights from the Behavioral and Brain Sciences, October 1, 2020. https://doi.org/10.1177/2372732220941536

Abstract: Psychological science informed recent policy changes granting increased rights for same-sex couples. Understanding that the link between science and policy goes both ways, how should policy inform the next generation of research concerning same-sex couples and sexual minority individuals? This article presents ways that psychological research influenced marriage policy and then puts forth suggestions for future research for the attention of scholars, funders, and policymakers. These include examinations of minority stress in the age of marriage equality; new stressors for same-sex couples including legal divorce; relationship expectations and experiences for emerging adults; and the potential impact of marriage equality for mixed-sex couples including a further challenge to strict gender roles in marriage. The article ends by acknowledging the need for continued application of research to emerging policy questions affecting same-sex couples and sexual minority individuals.

Keywords: same-sex couples, marriage equality, policy, romantic relationships, minority stress

Marriage does not relate to major histocompatibility complex: a genetic analysis based on 3691 couples

Marriage does not relate to major histocompatibility complex: a genetic analysis based on 3691 couples. Ilona Croy, Gerhard Ritschel, Denise Kreßner-Kiel, Laura Schäfer, Thomas Hummel, Jan Havlíček, Jürgen Sauter, Gerhard Ehninger and Alexander H. Schmidt. Proceedings of the Royal Society B: Biological Sciences, Volume 287, Issue 1936, October 7 2020. https://doi.org/10.1098/rspb.2020.1800

Abstract: Optimization of chances for healthy offspring is thought to be one of the factors driving mate choice and compatibility of the major histocompatibility complex (MHC) is assumed to determine the offspring's fitness. While humans have been claimed to be able to perceive information of MHC compatibility via the olfactory channel, it remains unknown whether humans use such information for mate choice. By investigation of 3691 married couples, we observed that the high polymorphism of MHC leads to a low chance for homozygous offspring. MHC similarity between couples did not differ from chance, we hence observed no MHC effect in married couples. Hormonal contraception at the time of relationship initiation had no significant effect towards enhanced similarity. A low variety of alleles within a postcode area led to a higher likelihood of homozygous offspring. Based on this data, we conclude that there is no pattern of MHC dis-assortative mating in a genetically diverse Western society. We discuss the question of olfactory mate preference, in-group mating bias and the high polymorphism as potential explanations.

Neighbourhood wealth, not urbanicity or population density, predicts prosociality towards strangers

Neighbourhood wealth, not urbanicity, predicts prosociality towards strangers. Elena Zwirner and Nichola Raihani. Proceedings of the Royal Society B: Biological Sciences, October 7 2020. https://doi.org/10.1098/rspb.2020.1359

Abstract: Urbanization is perhaps the most significant and rapid cause of demographic change in human societies, with more than half the world's population now living in cities. Urban lifestyles have been associated with increased risk for mental disorders, greater stress responses, and lower trust. However, it is not known whether a general tendency towards prosocial behaviour varies across the urban–rural gradient, or whether other factors such as neighbourhood wealth might be more predictive of variation in prosocial behaviour. Here, we present findings from three real-world experiments conducted in 37 different neighbourhoods, in 12 cities and 12 towns and villages across the UK. We measured whether people: (i) posted a lost letter; (ii) returned a dropped item; and (iii) stopped to let someone cross the road in each neighbourhood. We expected to find that people were less willing to help a stranger in more urban locations, with increased diffusion of responsibility and perceived anonymity in cities being measured as variables that might drive this effect. Our data did not support this hypothesis. There was no effect of either urbanicity or population density on people's willingness to help a stranger. Instead, the neighbourhood level of deprivation explained most of the variance in helping behaviour with help being offered less frequently in more deprived neighbourhoods. These findings highlight the importance of socio-economic factors, rather than urbanicity per se, in shaping variation in prosocial behaviour in humans.

4. Discussion

Our data do not support the idea that urbanicity is associated with reduced generalized prosociality. Instead, most of the variation in whether help was offered was explained by neighbourhood wealth, with help being more forthcoming in higher-wealth neighbourhoods. Our findings contrast with previous theories and empirical studies on the role of urbanicity in shaping prosocial behaviour (see [21,50] for reviews) but support more recent work that has implicated relative deprivation as being key to understanding variation in generalized prosociality and collective behaviour [34–36,51–54]. The effect of neighbourhood wealth on the tendency to help a stranger might help to explain why previous studies have reported decreased prosociality among urban dwellers. Although the pattern in the UK is quite mixed, there is quantitative evidence that rural areas are typically less deprived than more urban locations (a pattern than we also observe in the locations selected for this study) [42]. Previous findings that generalized cooperation is reduced in urban areas might, therefore, be masking the underlying instrumental variable, which relates to deprivation rather than to population density.

These data from a battery of real-world experiments lend more weight to the hypothesis that relative deprivation is negatively associated with generalized trust and prosociality. Several other studies have reported a similar pattern [34,52–61]. In experimental settings, exposure to harsh environments has been associated with an increased willingness to defect in a Prisoner's Dilemma game, and a reduced tendency to send money to a partner in a Dictator Game [36,62,63], and experimentally induced financial deprivation can increase the willingness to cheat for financial rewards [64]. Studies using the lost letter technique to measure prosociality have consistently reported increased return rates from higher-wealth neighbourhoods [34,35,56]. Large-scale, survey-based studies report similar findings. One recent study using more than 30 000 observations based on nationally representative samples concluded that high socio-economic status was associated with increased willingness to donate to charity, to volunteer to help, to contribute a higher proportion of income to charity, and to choose the prosocial option in an economic game [59] (see also [58]), while another large study (a total sample of greater than 60 000 and with participants from more than 30 countries) reported positive effects of household income on tendency to volunteer or to donate to charity ([60], but see [65], who performed a similar study, obtaining a null result). Finally, a study using data from more than 40 000 responses to the World Values Survey and the European Values Study, respectively, also suggests a negative link between exposure to environmental harshness and the tendency to invest in cooperative behaviour [52].

Nevertheless, other studies have reported negative effects of socio-economic status on prosocial and ethical behaviour [66–72]. We cannot account for the apparently contradictory findings in this field though we note that some of these earlier studies have been based on relatively small undergraduate samples [67,69] and several key results have failed to replicate in large-N, pre-registered replication attempts [73]. Other work has not found a main effect of social class on prosocial behaviour but has shown, instead, that the effect is moderated by third variables. For example, one study found that the effect of social class on social behaviour depends on whether the behaviour takes place in private or public [74], though we note that the effects of the interaction between class and anonymity on giving was inconsistent across different experiments in the study mentioned. Another study argued that the effect of social class on prosocial behaviour depends on whether lower-status individuals are exposed to high economic inequality [75], though two subsequent studies have failed to replicate this effect using similarly large datasets [58,60].

We note that our study differs from much of the work reported above in that we measured behaviour in the real world, rather than via online surveys or in the context of experimental games. In this true field experiment, it is possible that participants were also affected by the environment in which the behaviour was measured. For example, people are more likely to violate prosocial norms of collective behaviour where there is evidence that others do the same [76]—evidence that these norms are violated (e.g. litter and other indices of disorder) is typically higher in more deprived communities [77]. Other work has shown that prosocial behaviour is more likely when people have access to green space [78]. Importantly, access to green space is often lower in more deprived areas [77,79] or else is used less frequently by residents due to perceptions of being inaccessible or unsafe [79,80]. With our current dataset, it is impossible for us to determine whether the link between helping behaviour and deprivation pertains to the deprivation experienced by the participants or, alternatively, to the nature of the environment in which the studies were conducted, though we note that these explanations are not mutually exclusive.

Assuming that the negative association between neighbourhood levels of deprivation and the reduced tendency to help a stranger does exist, it begs the question as to how such a relationship might arise. There are several plausible routes by which deprivation might lead to reduced tendency to help a stranger. One of the most plausible routes might be through the effects that environmental harshness or unpredictability has on the tendency to invest to achieve larger rewards in the future, rather than taking immediately available, smaller pay-offs now. Investing to help a stranger has this incentive structure, where any downstream benefits of the helpful action are typically delayed and/or uncertain [38,81,82]. The effect of reduced income or lowered neighbourhood quality on the tendency to help a stranger could also be mediated by reduced social capital and generalized trust [83–86]. For example, a natural experiment in Russia found that a 10% decrease in average national income following the 2009 recession was associated with a 5% decrease in social trust [87]. Given that one of the help measures in our study (dropped item) involved a live interaction with a stranger, trust may well have been a relevant concern for people deciding whether to help or not. Another potential explanation for the link between adversity and willingness to help a stranger might be the role of material security and how this impacts the scale at which people cooperate [88–91]. In brief, this hypothesis predicts that as material security increases, people are more able to expand their social network, offering impartial help and cooperation to people beyond their core social group of known and regular interaction partners. We note that a prediction that derives from all these hypotheses (albeit one that we cannot test with our data) is that higher indices of deprivation in the UK will only affect the willingness to help a stranger, but not the willingness to help others that are part of one's existing community. Some empirical work supports the hypothesis that exposure to adversity or low socio-economic status is associated with an increased tendency to help friends or in-group members [70,71] though this hypothesis deserves further empirical attention.

We found mixed support for the hypothesis that help would be more likely when participants were directly requested to help. In the dropped item experiment, the direct request increased the likelihood of receiving help, whereas in the lost letter experiment, there was no difference in return rates across the direct request and no request conditions. These patterns may stem from the fact that the direct request in the dropped item experiment was made face-to-face, whereas in the lost letter experiment, the request was made remotely. The perceived costs of refusing to help when asked are likely to be higher in a face-to-face interaction, where the helper can be seen and potentially identified by the requester [26], and other work has shown that people are more cooperative in face-to-face interactions and/or when their name and picture are shown to others [26,30]. The difference we observe between the lost letter and the dropped item experiment helps to further quantify when and how direct requests might elicit help. Specifically, our study suggests that direct requests might increase helpful behaviour not because this reduces the diffusion of responsibility, but because a direct request increases the perceived reputation costs of refusing to help. This hypothesis could be explored in further experimental work.

We expected individuals in a group to help more than lone individuals as the presence of others would create the opportunity to accrue reputation benefits (e.g. [33,92,93]). However, in contrast with our expectations, we recorded higher helping from lone individuals than from individuals in groups in one of our experiments. One possibility is that individuals in social groups might be under greater perceptual load (e.g. in conversation with their acquaintance) which means that they do not note the helping opportunity. Another possibility is that people in groups experience greater perceived costs from pursuing an independent course of action (stopping to help an experimenter) that requires them to temporarily deviate from the group action, and also to impose the time costs associated with helping onto their acquaintance. We do not know of any study that addresses these latter possibilities empirically.

These results contribute to our understanding of the factors affecting variation in human cooperation. These data challenge the folk view that city dwellers are less cooperative than town dwellers and show that this variation may be a by-product of the association between urbanicity and deprivation. More generally, this study supports the hypothesis that deprivation reduces the willingness to extend impartial norms of cooperation towards strangers.