Increased subjective age (personal aging rate perception) increases mortality very much; biggest factors in SubjAge are physical health and expections of sex life in 10 years

PsychoAge and SubjAge: development of deep markers of psychological and subjective age using artificial intelligence. Alex Zhavoronkov et al. Aging, Volume 12, Issue 23 pp 23548—23577, December 8, 2020. https://doi.org/10.18632/aging.202344

Rolf Degen's take: Higher subjective age doubles mortality risk, and one of the top concomitants of subjective age is how satisfying people expect their sex life to be in 10 years’ time

Abstract

Aging clocks that accurately predict human age based on various biodata types are among the most important recent advances in biogerontology. Since 2016 multiple deep learning solutions have been created to interpret facial photos, omics data, and clinical blood parameters in the context of aging. Some of them have been patented to be used in commercial settings. However, psychological changes occurring throughout the human lifespan have been overlooked in the field of “deep aging clocks”.

In this paper, we present two deep learning predictors trained on social and behavioral data from Midlife in the United States (MIDUS) study: (a) PsychoAge, which predicts chronological age, and (b) SubjAge, which describes personal aging rate perception. Using 50 distinct features from the MIDUS dataset these models have achieved a mean absolute error of 6.7 years for chronological age and 7.3 years for subjective age. We also show that both PsychoAge and SubjAge are predictive of all-cause mortality risk, with SubjAge being a more significant risk factor.

Both clocks contain actionable features that can be modified using social and behavioral interventions, which enables a variety of aging-related psychology experiment designs. The features used in these clocks are interpretable by human experts and may prove to be useful in shifting personal perception of aging towards a mindset that promotes productive and healthy behaviors.

Discussion

In this article, we present two novel aging clocks created within the deep learning paradigm — PsychoAge and SubjAge. Both these clocks use the same set of 50 psychosocial features to estimate human chronological age and subjective age, respectively. These clocks showed superior performance during CV in MIDUS 1 (MAEPsychoAge= 6.70 years; MAESubjAge= 7.32 years) and were verified in two other large data sets — MIDUS 2 and MIDUS Refresher (Table 1). In terms of epsilon accuracy, PsychoAge reached a score of 0.78 in MIDUS 1, and SubjAge — 0.74.

Having trained and verified the final models, we aimed to understand how PsychoAge and SubjAge see human aging and what features they pay the most attention to. With a tandem PFI-DFS approach we ranked all features according to their relative importance. Top-5 important features in both clocks were associated with health conditions (e.g. headache frequency) and relationship status (marital status, expectations from sex life in 10 years). Less significant features greatly differ in their relative importance for SubjAge and PsychoAge predictions. For example, top-20 PsychoAge features contain only one personality trait — neuroticism. Meanwhile, the only personality traits encountered among top-20 SubjAge features are — extraversion and openness.

These three personality traits, along with conscientiousness and agreeableness form “the big five traits”, which are commonly used in practice and scientific research to describe the human mental state landscape. High neuroticism is characteristic of emotional instability and common mental disorders, such as mood disorders, anxiety, and substance use disorders. Openness and extraversion, on the other hand, are considered more balanced traits, although their abnormally low scores are also related to social phobia and agoraphobia [27]. Positive orientation, seeking warmth, social interaction, and emotional stability may play an important role in psychological aging.

We hypothesized that the human mind evolves throughout the lifespan, which results in some traits, beliefs, or priorities shifting — not always in unison or at the same speed. At certain life stages, career-related priorities may rise, while at others they may fade and be replaced by different priorities. These lifelong progressions of the psyche eventually get recognized by the neural networks we constructed to let them build an image of psychological aging.

This idea of human mind progression is described in much more detail in the review of SST by Laura Carstensen. SST suggests that younger people are more goal-oriented, interested to obtain new knowledge and skills, while older people tend to value emotionally meaningful goals more.

To identify the psychosocial features that change while a person advances from one age group to another we trained separate DNNs on MIDUS 1 samples from three age groups (25-39, 40-64, 65-75 years). First, we defined the psychological aging core — variables that remain highly important (top-25) across all age groups (Table 2). The core contained not only strictly psychological features, however. To illustrate, marital status, hypertension medication, headaches, and body mass index were among the seven core features required for accurate chronological age prediction. Interestingly, neuroticism score also belonged to the same psychological aging core, as well as seeing the community as a source of comfort. Psychological traits within the subjective aging core contained aspirations scale, extraversion, openness, positive reappraisal prevalence, and two career-related variables — effort put into work now and work expectations in 10 years. In contrast to the first psychological core, which contained few psychological traits, the subjective core consisted almost exclusively of psychological features.

This highlights an important distinction between aging per se (as judged by PsychoAge) and our perception of it (as judged by SubjAge): subjective aging is mostly dependent on internal causes.

We also explored the uniquely important features for each age group — features that emerged only in one top-25 set. Since these features were recognized as important only in these groups, it may be assumed that they shift the most markedly during the corresponding life periods. To illustrate, young adults were not the only age group who responded affirmatively to the statement “Forceful describes you well”, but rather many of these people went through a transformation that affected their forcefulness. Detecting such a change was essential for a predictor to accurately predict whether a person was at the beginning or the end of this phase of life.

On their own, DNNs are unable to tell generational and age-related changes apart or tell the difference between pro-longevity and progeroid features. Thus, the results of the feature importance analysis should always be cautiously inspected and verified in more rigorous settings. Still, feature importance analysis is a powerful tool for hypothesis generation and the verification of overall biological relevance.

While neuroticism was identified as a part of the psychological aging core, it was also a uniquely important subjective aging feature in the elderly MIDUS 1 subsample. This may be interpreted as neuroticism progressing unnoticed by an individual until old age when it starts to affect the perception of age. Previous studies identified that neuroticism tends to cause low emotional differentiation, anxiety, and depression in old people [28, 29].

Other personality traits rendered important for subjective age estimation in the elderly were optimism, being outgoing, and content with life in general. These results indicate that these might be top-priority features to focus on while developing policies aimed to involve the elderly in social life. Several studies have shown the importance of a social and productive lifestyle during aging [30, 31]. psychologically important and active events may protect against aging diseases, such as dementia [32].

After establishing which variables are important in absolute terms, we aimed to measure the models’ response to changes in their values. Using mixed-effects linear models, we explored the monotonic trends between 50 variables, PsychoAge and SubjAge predictions (Supplementary Figure 1 and Supplementary Figure 2).

Once again, neuroticism showed unique behavior. Contrary to the other big five traits, neuroticism score was associated with higher SubjAge and lower PsychoAge. More specifically, people within the same PsychoAge group could have >5 years of SubjAge difference due to differences in neuroticism score alone. This verifies our previous conjecture that neuroticism is a key marker of subjective aging and may be used as a sensitive measure of emotional states and late-life depressive symptoms.

Other big five traits also had significantly large effects on both PsychoAge and SubjAge. For example, a person with the bottom openness score would feel 7.2 years older than their PsychoAge counterpart with the top score. In the meantime, a person with the bottom openness score would be 5.3 years younger, as measured by PsychoAge, than their SubjAge counterpart with the top score. Similar tendencies could be observed for most other personality traits, thus building a strong case for SST.

Interestingly, personal opinion on when middle age starts and ends was significantly associated with higher PsychoAge but does not affect SubjAge. We hypothesize that this is an indication of “time dilation” associated with aging. As people get older, they place “middle age” higher and higher, as if their lifetime dilates, while younger participants may have stereotypes about aging and place “middle age” lower. An excellent study on the topic of perception of age stereotypes and self-perception of aging has been written by Hummert [33].

Among the health-related features, the distinction between internal and external health locus of control is of utmost interest. Health locus of control is a set of personal beliefs and experiences that determine whether a person takes responsibility for their health (internal locus) or considers it to be outside of their power, fully dependent on external factors (external locus). Internal locus of control is associated with a problem-solving mindset, while external locus is tied to depression, anxiety, and suicidal thoughts, as well as maladaptive behaviors [34]. We demonstrated that external locus of health control is a rare feature that demonstrated a linearly positive effect on both PsychoAge and SubjAge. It was the only feature to offer no payoff in at least one aging dimension, except for “Taking prescription medications for blood pressure”. Internal control, per contra, did not display concordant linearly negative effect on. Instead, it decreased SubjAge and decreased PsychoAge, just as most other health-related variables.

While the external locus of control was a senopositive (higher values increase age predictions) feature in both aging dimensions, some features were identified as double senonegative (higher values decrease age predictions). Increasing values for the variables from the relationships category were associated with lower PsychoAge and SubjAge, thus favoring single people content with their sex life, who expected to remain sexually active in 10 years. In this case, it is difficult to conclude the cause-effect relation between psychological aging and sexuality. Is reduced libido a precondition to becoming subjectively old? Or does feeling old due to other factors make people less interested in the sexual aspect of life? Can more satisfying sex life prolong healthy longevity, or does PsychoAge simply see higher sex drive as a feature more frequently encounter in the youth? More thorough research is required to answer these questions as well as similar questions concerning other variables.

Although the effect of most variables on PsychoAge and SubjAge was shown to be discordant, the magnitude of their effects on these two measures of psychological aging is not equal. Since the target variable in the mixed-effects model is expressed in years, Table 3 can be used to approximate how a shift in a psycho-social parameter will affect PsychoAge or SubjAge, and which one of them will change more. For example, the variable “Rate health in 10 years” is a survey question that measures health expectation on a scale from 0 to 10, from worst to best. Each increment increases PsychoAge by 0.5 years but also decreases SubjAge by 1.0 years. This yields an “exchange rate” of 2 subjective years lost per 1 chronological age gained. Other features have their own exchange rates, which may be manipulated to accumulate “net profit” in both SubjAge and PsychoAge dimensions.

Other directional feature analysis methods may be more appropriate for navigating the psychological aging landscape since linear mixed effect models operate based on multiple assumptions and simplifications. More specifically, they treat all features independently and approximate the complex interrelations between PsychoAge and SubjAge that may be in place with a random intercept. Accumulated local effects or more sophisticated Shapley value analysis may handle the convoluted feature interrelations more efficiently.

To further validate PsychoAge and SubjAge we tested their prediction errors (delta) as all-cause mortality risk factors (Figure 6). SubjAge delta was proven to be a more powerful risk factor than PsychoAge. More specifically, the SubjAge delta beyond ±5 years was associated with roughly doubling or halving the mortality rate.

We also tested the 50 psychosocial markers of aging as risk factors. We identified significant mortality risks associated with certain factors among (i) health features (“Health compared to others your age”, “Rate current health”, “Shortness of breath while walking up a slight hill”), (ii) personality traits (“Conscientiousness personality trait”, “Agency personality trait”), (iii) psychological beliefs (“Live for today”, “Positive reappraisal”, “Lower aspirations”), (iv) well-being (“Satisfied with life at present”), and, (v) demographic factors (“Chronological age”) (Figure 7).

A problem frequently encountered even by psychologists is obtaining sufficiently detailed information about their patients while keeping the data collection process as short as possible to avoid survey fatigue. In this work, we propose a solution to this survey length-descriptiveness balance problem based on modern deep learning and biogerontological methods. The solution is a relatively short list of features that are both modifiable and provably important in the context of aging.

Some studies show that family history is a source of numerous highly important aging-related features [35]. For example, having long-lived parents and grandparents is strongly correlated with a longer lifespan. However, such factors are not easily modified, especially if the grandparents are no longer alive. Therefore, in this study, we have deliberately limited questions on non-modifiable historical factors to give our surveys more practical value. We demonstrated that variables related to health and closer personal relationships play a crucial role in chronological and subjective age prediction. Furthermore, images about life changes, for instance, when females or males enter middle age, demonstrate a strong predictive power. We suggest that modifying the behavior and the mindset via these variables may be a promising therapeutic concept.

The factors comprising the developed aging clocks can be used to create individual behavioral therapies that would make them feel and actually become biologically younger. For example, PsychoAge can be used to quantify the beneficial effects of daily vigorous-intensity activity on their rate of aging. SubjAge, in its turn, can be used to quantify the beneficial effects of physical activity on personal perception of age.

Focusing on such modifiable age-related features while being able to score lifestyle choices numerically offers interesting opportunities to both professional therapists and individuals seeking self-improvement. We believe that the described approach has a high potential to increase longevity conscience on a population level.

When the category of close relationships is considered, people with access to PsychoAge and SubjAge may choose to develop stronger bonds, get married, or stay married out of an egoistic incentive to prolong their healthspan. The beneficial effect of close relationships and intimacy on health was previously shown in multiple studies, and we believe that drawing people’s attention to such physical-mental health connections should not be neglected [36].

Extracting actionable items from human biological profiles, such as transcriptomic or proteomic profiles, is an actively researched subject. The profiles associated with human psychology can also be subjected to similar workflows to devise personal behavioral therapy plans. In this study, we have demonstrated how the combination of deep learning and aging clocks can be used to create psychological surveys that promote longevity consciousness and personal improvement. These tools and methods could be applied in a wide range of research areas, including psychiatry, longevity, psychology, and psychophysiology for the greater good of society.

Inducing cognitive structure led novice consumers to experience numbness (less intense emotion); however, shifting experts away from using their cognitive structure restored their experience of emotion

Emotionally Numb: Expertise Dulls Consumer Experience. Matthew D Rocklage, Derek D Rucker, Loran F Nordgren. Journal of Consumer Research, ucab015, March 15 2021. https://doi.org/10.1093/jcr/ucab015

Abstract: Expertise provides numerous benefits. Experts process information more efficiently, remember information better, and often make better decisions. Consumers pursue expertise in domains they love and chase experiences that make them feel something. Yet, might becoming an expert carry a cost for these very feelings? Across more than 700,000 consumers and 6 million observations, developing expertise in a hedonic domain predicts consumers becoming more emotionally numb – i.e., having less intense emotion in response to their experiences. This numbness occurs across a range of domains – movies, photography, wine, and beer – and across diverse measures of emotion and expertise. It occurs in cross-sectional real-world data with certified experts, and in longitudinal real-world data that follows consumers over time and traces their emotional trajectories as they accrue expertise. Further, this numbness can be explained by the cognitive structure experts develop and apply within a domain. Experimentally inducing cognitive structure led novice consumers to experience greater numbness. However, shifting experts away from using their cognitive structure restored their experience of emotion. Thus, although consumers actively pursue expertise in domains that bring them pleasure, the present work is the first to show that this pursuit can come with a hedonic cost.

Keywords: expertise, emotion, hedonic, consumer knowledge, language, attitudes

Primate landscape genetics: A review and practical guide

Primate landscape genetics: A review and practical guide. Westphal D, Mancini AN, Baden AL. Evolutionary Anthropology, Mar 15 2021, DOI: 10.1002/evan.21891 PMID: 33720482

Abstract: Landscape genetics is an emerging field that integrates population genetics, landscape ecology, and spatial statistics to investigate how geographical and environmental features and evolutionary processes such as gene flow, genetic drift, and selection structure genetic variation at both the population and individual levels, with implications for ecology, evolution, and conservation biology. Despite being particularly well suited for primatologists, this method is currently underutilized. Here, we synthesize the current state of research on landscape genetics in primates. We begin by outlining how landscape genetics has been used to disentangle the drivers of diversity, followed by a review of how landscape genetic methods have been applied to primates. This is followed by a section highlighting special considerations when applying the methods to primates, and a practical guide to facilitate further landscape genetics studies using both existing and de novo datasets. We conclude by exploring future avenues of inquiry that could be facilitated by recent developments as well as underdeveloped applications of landscape genetics to primates.

On days when anxiously attached people perceived their partner as responsive to their sexual needs, they reported similar levels of relationship and sexual satisfaction, trust, and commitment as people lower in anxiety

Raposo, S., & Muise, A. (2021). Perceived partner sexual responsiveness buffers anxiously attached individuals’ relationship and sexual quality in daily life. Journal of Family Psychology, Mar 2021. https://doi.org/10.1037/fam0000823

Abstract: Satisfying relationships are central to health and well-being, yet the insecurities of anxiously attached people can detract from the quality of their romantic relationships. One factor associated with relationship quality is perceiving a partner as responsive to one’s needs, and responsiveness to a partner’s sexual needs might be a particularly powerful way to signal responsiveness to anxiously attached partners. In a 21-day daily experience and longitudinal study of 121 couples, we tested perceived partner sexual responsiveness as a buffer against the lower relationship quality (satisfaction, commitment, trust) and sexual satisfaction that anxiously attached people typically experience. On days when anxiously attached people perceived their partner as responsive to their sexual needs, they reported similar levels of relationship and sexual satisfaction, trust, and commitment as people lower in anxiety. Perceived partner sexual responsiveness was also important for maintaining commitment over time. Our findings suggest that perceived partner sexual responsiveness is one promising protective factor for anxiously attached partners. 

Men’s higher benevolent sexism predicted lower aggressive parenting, & women’s higher benevolent sexism predicted greater aggressive behavior toward partners, irrespective of power & relationship quality

Overall, N. C., Chang, V. T., Cross, E. J., Low, R. S. T., & Henderson, A. M. E. (2021). Sexist attitudes predict family-based aggression during a COVID-19 lockdown. Journal of Family Psychology, Mar 2021. https://doi.org/10.1037/fam0000834

Abstract: The current research examined whether men’s hostile sexism was a risk factor for family-based aggression during a nationwide COVID-19 lockdown in which families were confined to the home for 5 weeks. Parents who had reported on their sexist attitudes and aggressive behavior toward intimate partners and children prior to the COVID-19 pandemic completed assessments of aggressive behavior toward their partners and children during the lockdown (N = 362 parents of which 310 were drawn from the same family). Accounting for pre-lockdown levels of aggression, men who more strongly endorsed hostile sexism reported greater aggressive behavior toward their intimate partners and their children during the lockdown. The contextual factors that help explain these longitudinal associations differed across targets of family-based aggression. Men’s hostile sexism predicted greater aggression toward intimate partners when men experienced low power during couples’ interactions, whereas men’s hostile sexism predicted greater aggressive parenting when men reported lower partner–child relationship quality. Novel effects also emerged for benevolent sexism. Men’s higher benevolent sexism predicted lower aggressive parenting, and women’s higher benevolent sexism predicted greater aggressive behavior toward partners, irrespective of power and relationship quality. The current study provides the first longitudinal demonstration that men’s hostile sexism predicts residual changes in aggression toward both intimate partners and children. Such aggressive behavior will intensify the health, well-being, and developmental costs of the pandemic, highlighting the importance of targeting power-related gender role beliefs when screening for aggression risk and delivering therapeutic and education interventions as families face the unprecedented challenges of COVID-19.

Extraverts report higher levels of authenticity and extraverted behavior predicts increased feelings of authenticity, even by introverts

Wilt, Joshua A., Jessie Sun, Rowan Jacques-Hamilton, and Luke D. Smillie. 2021. “Why Does It Feel Authentic to Be and Act Extraverted? Exploring the Mediating Role of Positive Affect.” PsyArXiv. March 19. doi:10.31234/osf.io/7mj6g

Abstract: Extraverts report higher levels of authenticity and extraverted behavior predicts increased feelings of authenticity. Why? Across three studies, we examined positive affect as a mediator of the associations between extraversion and authenticity. In Study 1 (N = 205), we tested our mediation model at the trait level. Study 2 (N = 97) involved a ten-week lab-based experience sampling protocol, whereas Study 3 (N = 147) involved a preregistered week-long daily-life experience sampling protocol. These studies allowed us to test our mediation model at the state level. Positive affect explained moderate to very high proportions of the effects of extraversion on authenticity (Study 1 = 29%, Study 2 = 38%, Study 3 = 87%). We interpret these findings through the lens of cybernetic self-regulation, feelings-as-information, positive psychology, and humanistic perspectives, and propose that increased PA could also explain why extraversion is connected with other eudaimonic components of wellbeing.

Participants who were exposed to a salient health threat (loud coughing after the COVID-19 epidemic started) displayed a lower level of overconfidence than did participants in the control condition

The bright side of the COVID-19 pandemic: Public coughing weakens the overconfidence bias in non-health domains. Heng Li, Yu Cao. Personality and Individual Differences, March 19 2021, 110861. https://doi.org/10.1016/j.paid.2021.110861

Abstract: The COVID-19 pandemic is a serious threat that produces harm to people around the globe. Prior work has almost exclusively focused on deconstructive consequences of the novel coronavirus, the present research reveals a bright side of the coronavirus outbreak: reduce the overconfidence bias in non-health domains. In Experiment 1, students passed by a trained confederate who was coughing loudly or not and completed a peer-comparison problem measuring their overconfidence bias. The results showed that participants, who were exposed to a salient health threat, displayed a lower level of overconfidence than did participants in the control condition. Experiment 2 recapitulated the effects of public coughing on overconfidence by using a non-student sample and an alternative measure of overconfidence. Across two field experiments, we replicated prior findings regarding sex differences for the overconfidence bias. Taken together, our research suggests that whereas the COVID-19 pandemic has undoubtedly ravaged nations and economies, the unprecedented crisis offers an opportunity for individuals to counteract their overconfidence in judgment and decision-making.

Keywords: COVID-19Disease threatOverconfidenceSex differencesRisk perceptionField experiments

People were relatively modest and self-critical about their ideas’ funniness; women rated their responses as less funny; & people showed some discernment and insight into their ideas’ funniness

If You’re Funny and You Know It: Personality, Gender, and People’s Ratings of Their Attempts at Humor. Paul J. Silvia et al. Journal of Research in Personality, March 19 2021, 104089. https://doi.org/10.1016/j.jrp.2021.104089

Rolf Degen's take: Although people consider themselves "funnier than average", they are relatively modest and self-critical about their own jokes’ funniness

Highlights

• In seven studies (n = 1,133), adults rated the funniness of their attempts at humor.

• People were relatively modest and self-critical about their ideas’ funniness.

• Extraversion and openness to experience predicted rating one’s responses as funnier.

• Women rated their responses as less funny.

• People showed some discernment and insight into their ideas’ funniness.

Abstract:  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. In contrast to the common “funnier than average” effect found for global self-ratings, people were relatively modest and self-critical about their specific 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.

Keywords: humorcomedycreativitypersonalitygenderdiscernment

I know a dog when I see one: dogs (Canis familiaris) recognize dogs from videos

I know a dog when I see one: dogs (Canis familiaris) recognize dogs from videos. Paolo Mongillo, Carla Eatherington, Miina Lõoke & Lieta Marinelli. Animal Cognition, Mar 19 2020. https://rd.springer.com/article/10.1007/s10071-021-01470-y

Critical view... Big breakthrough in science: Dogs can recognize their own kind in videos and are baffled when a cow barks

Abstract: Several aspects of dogs’ visual and social cognition have been explored using bi-dimensional representations of other dogs. It remains unclear, however, if dogs do recognize as dogs the stimuli depicted in such representations, especially with regard to videos. To test this, 32 pet dogs took part in a cross-modal violation of expectancy experiment, during which dogs were shown videos of either a dog and that of an unfamiliar animal, paired with either the sound of a dog barking or of an unfamiliar vocalization. While stimuli were being presented, dogs paid higher attention to the exit region of the presentation area, when the visual stimulus represented a dog than when it represented an unfamiliar species. After exposure to the stimuli, dogs’ attention to different parts of the presentation area depended on the specific combination of visual and auditory stimuli. Of relevance, dogs paid less attention to the central part of the presentation area and more to the entrance area after being exposed to the barking and dog video pair, than when either was paired with an unfamiliar stimulus. These results indicate dogs were surprised by the latter pairings, not by the former, and were interested in where the barking and dog pair came from, implying recognition of the two stimuli as belonging to a conspecific. The study represents the first demonstration that dogs can recognize other conspecifics in videos.

Discussion

In this study, we employed a cross-modal, expectancy violation paradigm to assess whether dogs can recognize the species of conspecifics from videos. Dogs were presented with pairs of auditory and visual stimuli, which could be any combination of dog-related on non-dog-related vocalization and video. Dogs’ orientation towards the presentation area, as a function of the presented pair of stimuli, was analysed during two time intervals, in which different mechanisms were most likely at play.

The first interval spanned from the onset of the vocalization to the last frame in which the video of the animal crossing the screen was visible. Dogs’ orientation in this interval therefore reflected a proximate reaction to the presence of the stimuli, rather than an after-effect of the pairing.

Dogs spent almost the entire interval oriented toward the projection area. Moreover, dogs’ attention to specific regions of the projection area roughly followed the stimulus occupation of such regions. This finding is most likely a direct result of the capacity of motion stimuli to elicit orientation responses, an effect that is particularly relevant for stimuli abruptly appearing within the visual field (Hillstrom and Yantis 1994) and for stimuli depicting animate entities (Pratt et al. 2010), two features that characterised the visual stimuli that were presented in this experiment.

A breakdown analysis of dogs’ orientation to the different parts of the projection area revealed that dogs spent longer time looking at the exit area when a dog video was projected than when the unfamiliar species was projected. Therefore, dogs were more likely to visually follow the dogs’ video until it left the presentation area, than the unfamiliar species video. The finding is consistent with the notion that familiarity drives attentional responses for visual stimuli (Christie and Klein 1995). There is some direct evidence that this process also applies to dogs, in particular when presented with representations of dogs’, such as face photographs (Racca et al. 2010) or biological movement (Eatherington et al. 2019). Overall, the findings support the idea that dogs did at least perceive the dog video as a familiar stimulus.

Evidence that dogs did recognise the dog-related stimuli as belonging to a dog, however, comes from the analysis of attention patterns after the stimuli had disappeared. In this time interval, dogs spent less time oriented towards the central part of the presentation area when a bark was followed by the appearance of a dog video, than when any of such two stimuli was paired with an unfamiliar counterpart. In accordance with the violation of expectancy paradigm, longer looking at the main projection area reflected a surprised reaction to the pairing of an unfamiliar-species stimulus with a dog stimulus. Analogous interpretations of longer looking times have been found in studies in dogs (Adachi et al. 2007) and other species including cats (Takagi et al. 2019), horses (Lampe and Andre 2012; Nakamura et al. 2018), crows (Kondo et al. 2012) and lions (Gilfillan et al. 2016). Therefore, this result clearly indicates that dogs perceived the appearance of the dog video as an expected consequence of the barking, implying they had appropriately recognized both stimuli as belonging to a dog. Following presentation of dog stimuli, dogs also spent longer time looking at the entrance region of the presentation area, than when either dog stimulus was paired with an unfamiliar-species stimulus. No such effect was observed for attention to the exit region. Although the reason for this pattern of results is not immediately clear, we believe the result is further indication that dogs retained the pair of dog stimuli as coherently representing a dog; in this sense, dogs may have been interested in where the animal came from, especially since nothing indicated the presence of such animal before its sudden appearance. The lack of differences in attention to the exit region, on the other hand, could reflect a relatively low need to monitor an animal who was moving away from the observer.

When both stimuli belonged to an unfamiliar species, the pattern of dogs’ attention to the presentation area was less clear-cut than those observed when presented with dog stimuli. On the one hand, attention to the central part of the presentation area when non-dog stimuli were paired was not different than that observed when dog stimuli were paired. The similarity in reaction may suggest dogs considered the appearance of the unfamiliar individual as a plausible consequence of the unfamiliar vocalization, much as they considered the appearance of the dog an unsurprising consequence of the bark. Unsurprised reactions to pairs of unfamiliar stimuli in an expectancy violation test have also been reported before (e.g. Adachi et al. 2007). As already discussed for the pair of dog stimuli, the high amount of attention paid to the entrance region could indicate the interest in where an unknown (but plausible) type of animal came from. On the other hand, dogs’ attention to the central part of the presentation area after non-dog stimuli pairs were presented was also not lower than when a dog/non-dog stimuli pair was presented. A possible explanation is that dogs’ attention patterns after being exposed to the two unfamiliar stimuli was driven by the interest in such novel stimuli, rather than by a violated expectation. Indeed, different studies showed neophilic reactions by dogs (e.g. Kaulfuß and Mills 2008; Racca et al. 2010). Of particular relevance, as it deals with visual preference, the study by Racca and collaborators (2010) showed that while dogs pay preferential attention to familiar rather than novel images of dogs, the opposite is true for other classes of stimuli, including images of objects or of human faces. Along this reasoning, hearing a novel auditory stimulus drove attention to the entrance region, and seeing a novel visual stimulus drove attention to both the entrance and central region (the latter being predominantly occupied when the stimulus became fully visible).

One question arising from our results whether dogs showed a different response to the pairing of the bark and dog video merely because they were familiar with both stimuli, without implying classification of the stimuli as belonging to a dog. The literature provides some indications that this may not be the case. For instance, Gergely and collaborators (2019) showed that dogs exposed to a conspecific vocalization pay more attention to pictures of dogs than of humans, a species dogs were highly familiar with. Moreover, a recent functional neuroimaging study revealed greater activation of visual cortical areas in dogs, when exposed to videos of conspecific faces than when exposed to human faces, suggesting the existence of species-specific processing mechanisms (Bunford et al. 2020). Taken together, these findings suggest dogs do possess the ability to visually discriminate dogs from another familiar species. Whether such ability is the result of exposure alone or is aided by a predisposition is impossible to state by the results of the present or of other studies in dogs. Findings in humans indicate that experience builds on top of predispositions in determining one’s ability to identify motion features as belonging to a conspecific (reviewed by Hirai and Senju 2020). A thorough understanding of if and how the same factors impact on dogs’ ability to recognize other animals would require further experiments, which are currently ongoing in our laboratory.

Few other studies have attempted to demonstrate dogs’ ability to recognize the species of other conspecifics in figurative representations, providing suggestive though not conclusive evidence (Autier-Dérian et al. 2013; Gergely et al. 2019). The present findings differ in important ways from all previous attempts. First, in all other studies, the stimuli depicted animal heads, whereas our stimuli represented lateral views of the animal’s whole body. Our findings imply that a detailed frontal view of the head is not a necessary stimulus for dogs to recognize a conspecific, at least if motion information is available. Indeed, a crucial difference between the present and earlier studies was that we presented videos rather than still images, allowing us to incorporate information about movement. Our own laboratory showed dogs are attracted by the motion of a laterally walking dog (Eatherington et al. 2019) and studies in other species highlight how motion cues alone can be used for the recognition of conspecifics (Jitsumori et al. 1999; Nunes et al. 2020). Thus, the presence of motion information in our experiment may have played a role in allowing dogs to appropriately identify the conspecific’s video. The abovementioned studies indicate that morphology, independently from motion, can also be individually sufficient to the aims of recognition (Jitsumori et al. 1999; Nunes et al. 2020). However, these studies only depicted heads, a stimulus that is rich in features useful to the aims of recognition, even to the level of the individual. Our findings indicate that even more limited morphological details provided by a lateral, whole body view, paired with motion information may be sufficient for dogs to recognize a conspecific.

Finally, research on dog visual cognition has used the cross-modal and expectancy violation paradigms; for instance, similar paradigms have been successfully used to demonstrate dogs’ recognition of humans’ identity or sex (Adachi et al. 2007; Ratcliffe et al. 2014), or expectations about conspecifics’ body size (Taylor et al. 2011). However, to the best of our knowledge, this method had never been used in dogs with videos and some methodological considerations seem useful at this stage. First, while videos were projected, dogs spent most of their time oriented towards the presentation area, indicating the stimuli were able to attract the dogs’ attention (at least from a behavioural standpoint), a crucial and often problematic aspect of research on visual cognition. Second, even after the stimulus disappeared, dogs remained oriented towards the presentation area for a significant portion of the allowed 30 s—suggesting maintenance of interest in what had been projected. Third, the analysis of dogs’ orientation across subsequent presentations suggests limited habituation through the first two trials, but a significant decrement starting from the third trial. Overall, these results indicate the method is suitable to study dogs’ spontaneous cross-modal processing of auditory and animated visual stimuli, and that dogs can be presented with up to two presentations before their attention starts to decline.

From 2017... Who Wants To Live Forever? Explaining the Cross-Cultural Recurrence of Reincarnation Beliefs

Who Wants To Live Forever? Explaining the Cross-Cultural Recurrence of Reincarnation Beliefs. Claire White. Journal of Cognition and Culture, vol 17, issue 5, pp 419–436. Nov 2017. https://doi.org/10.1163/15685373-12340016

Abstract: Around 30% of world cultures endorse reincarnation and 20% of contemporary Americans think that reincarnation is plausible. This paper addresses the question of why belief in reincarnation is so pervasive across geographically disparate contexts. While social scientists have provided compelling explanations of the particularistic aspects of reincarnation, less is known about the psychological foundations of such beliefs. In this paper, I review research in the cognitive science of religion to propose that selected panhuman cognitive tendencies contribute to the cross-cultural success of basic ideas in reincarnation. Together, this research suggests that extraordinary convictions, including those associated with postmortem survival, are underpinned by some of the same processes that govern mundane social cognition.

Keywords: Reincarnation, Cognitive Science of Religion, Social cognition, the afterlife.

Check also, from 2018... Contemporary Post-mortem Survival Narratives are popular & convincing, in part, because they meet default cognitive assumptions about what human survival would look like if it were possible:

How to Know You’ve Survived Death: A Cognitive Account of the Popularity of Contemporary Post-mortem Survival Narratives. Claire White, Michael Kinsella, Jesse Bering. Method & Theory in the Study of Religion, Volume 30, Issue 3, Pages 279–299. Jul 24 2018. https://www.bipartisanalliance.com/2021/03/contemporary-post-mortem-survival.html

59 societies: In individualistic societies, passion predicts a larger gain & explains more variance in achievement; in contrast, in collectivistic societies, parental support predicts achievement over & above passion

Passion matters but not equally everywhere: Predicting achievement from interest, enjoyment, and efficacy in 59 societies. Xingyu Li, Miaozhe Han, Geoffrey L. Cohen, and  Hazel Rose Markus. Proceedings of the National Academy of Sciences, March 16, 2021 118 (11) e2016964118; https://doi.org/10.1073/pnas.2016964118

Significance: In three large-scale datasets representing adolescents from 59 societies across the globe, we find evidence of a systematic cultural variation in the relationship between passion and achievement. In individualistic societies, passion better predicts achievement and explains more variance in achievement outcomes. In collectivistic societies, passion still positively predicts achievement, but it is a much less powerful predictor. There, parents’ support predicts achievement as much as passion. One implication of these findings is that if admission officers, recruiters, and managers rely on only one model of motivation, a Western independent one, they may risk passing over and mismanaging talented students and employees who increasingly come from sociocultural contexts where a more interdependent model of motivation is common and effective.

Abstract: How to identify the students and employees most likely to achieve is a challenge in every field. American academic and lay theories alike highlight the importance of passion for strong achievement. Based on a Western independent model of motivation, passionate individuals—those who have a strong interest, demonstrate deep enjoyment, and express confidence in what they are doing—are considered future achievers. Those with less passion are thought to have less potential and are often passed over for admission or employment. As academic institutions and corporations in the increasingly multicultural world seek to acquire talent from across the globe, can they assume that passion is an equally strong predictor of achievement across cultural contexts? We address this question with three representative samples totaling 1.2 million students in 59 societies and provide empirical evidence of a systematic, cross-cultural variation in the importance of passion in predicting achievement. In individualistic societies where independent models of motivation are prevalent, relative to collectivistic societies where interdependent models of motivation are more common, passion predicts a larger gain (0.32 vs. 0.21 SD) and explains more variance in achievement (37% vs. 16%). In contrast, in collectivistic societies, parental support predicts achievement over and above passion. These findings suggest that in addition to passion, achievement may be fueled by striving to realize connectedness and meet family expectations. Findings highlight the risk of overweighting passion in admission and employment decisions and the need to understand and develop measures for the multiple sources and forms of motivation that support achievement.

Being male and having higher arousal in response to erotic stimuli, however, was associated with a greater willingness to engage in coercive sex

Sex, sexual arousal, and sexual decision making: An evolutionary perspective. Courtney L. Crosby, David M. Buss, Lawrence K. Cormack, Cindy M. Meston. Personality and Individual Differences, Volume 177, July 2021, 110826., https://doi.org/10.1016/j.paid.2021.110826

Abstract: Sexual arousal is conceptualized as a motivational system that prioritizes mating and minimizes the perceived risks associated with sex. Previous studies show that when sexually aroused, individuals are more likely to endorse engaging in risky sexual behaviors. A majority of these studies examine a restricted number of sexual behaviors or do not test evolutionarily-relevant sex differences. Due to gender asymmetries in the minimum obligatory costs of parental investment, the costs of injudicious sexual decisions tend to be greater for women. As such, men and women may respond in disparate ways when sexually aroused. We extend previous research by investigating the effect of experimentally manipulated sexual arousal on sexual decision-making in men and women (N = 140). We found no significant difference between individuals exposed to neutral or erotic stimuli on the willingness to engage in experimental or coercive sex. Being male and having higher arousal in response to erotic stimuli, however, was associated with a greater willingness to engage in coercive sex. Results suggest that individual differences in sexual arousal following exposure to erotic stimuli may be critical for understanding sexual strategies, particularly those pertaining to sexual coercion.

Keywords: Sexual arousalSexual decision makingSexual coercionSexual behaviorEvolutionary theory

Project Debater, an autonomous debating system that can engage in a competitive debate with humans

An autonomous debating system. Noam Slonim et al. Nature volume 591, pp379–384, Mar 17 2021. https://www.nature.com/articles/s41586-021-03215-w

Abstract: Artificial intelligence (AI) is defined as the ability of machines to perform tasks that are usually associated with intelligent beings. Argument and debate are fundamental capabilities of human intelligence, essential for a wide range of human activities, and common to all human societies. The development of computational argumentation technologies is therefore an important emerging discipline in AI research1. Here we present Project Debater, an autonomous debating system that can engage in a competitive debate with humans. We provide a complete description of the system’s architecture, a thorough and systematic evaluation of its operation across a wide range of debate topics, and a detailed account of the system’s performance in its public debut against three expert human debaters. We also highlight the fundamental differences between debating with humans as opposed to challenging humans in game competitions, the latter being the focus of classical ‘grand challenges’ pursued by the AI research community over the past few decades. We suggest that such challenges lie in the ‘comfort zone’ of AI, whereas debating with humans lies in a different territory, in which humans still prevail, and for which novel paradigms are required to make substantial progress.

Popular version: https://www.nature.com/articles/d41586-021-00539-5

Discussion

Research in AI and in natural language processing is often focused on so called ‘narrow AI’, consisting of narrowly defined tasks. The preference for such tasks has several reasons. They require less resources to pursue; typically have clear evaluation metrics; and are amenable to end-to-end solutions such as those stemming from the rapid progress in the study of deep learning techniques37. Conversely, ‘composite AI’ tasks—namely, tasks associated with broader human cognitive activities, which require the simultaneous application of multiple skills—are less frequently tackled by the AI community. Here, we break down such a composite task into a collection of tangible narrow tasks and develop corresponding solutions for each. Our results demonstrate that a system that properly orchestrates such an arsenal of components can meaningfully engage in a complex human activity, one which we presume is not readily amenable to a single end-to-end solution. Since the 1950s AI has advanced in leaps and bounds, thanks, in part, to the ‘grand challenges’, in which AI technologies performed tasks of growing complexity. Often, this was in the context of competing against humans in games which were thought to require intuitive or analytic skills that are particular to humans. Examples range from chequers38, backgammon39, and chess40, to Watson winning in Jeopardy!41 and Alpha Zero winning at Go and shogi42. We argue that all these games lie within the ‘comfort zone’ of AI, whereas many real-world problems are inherently more ambiguous and fundamentally different, in several ways. First, in games there is a clear definition of a winner, facilitating the use of reinforcement learning techniques39,42. Second, individual game moves are clearly defined, and the value of such moves can often be quantified objectively (for example, see ref. 43), enabling the use of game-solving techniques. Third, while playing a game an AI system may come up with any tactic to ensure winning, even if the associated moves could not be easily interpreted by humans. Finally, for many AI grand challenges, such as Watson41 and Alpha Star44, massive amounts of relevant structured data (for example, in the form of complete games played by humans) was available and imperative for the development of the system. These four characteristics do not hold in competitive debate, which requires an advanced form of using human language, one with much room for subjectivity and interpretation. Correspondingly, often there is no clear winner. Moreover, even if we had a computationally efficient ‘oracle’ to determine the winner of a debate, the sheer complexity of a debate—such as the amount of information required to encode the ‘board state’ or to enumerate all possible ‘moves’—prohibits the use of contemporary game-solving techniques. In addition, it seems implausible to win a debate using a strategy that humans can fail to follow, especially if it is the human audience which determines the winner. And finally, structured debate data are not available at the scale required for training an AI system. Thus, the challenge taken by Project Debater seems to reside outside the AI comfort zone, in a territory where humans still prevail, and where many questions are yet to be answered.

What Does Women’s Facial Attractiveness Signal? Implications for an Evolutionary Perspective on Appearance Enhancement

What Does Women’s Facial Attractiveness Signal? Implications for an Evolutionary Perspective on Appearance Enhancement. Benedict C. Jones, Alex L. Jones, Victor Shiramizu & Claire Anderson. Archives of Sexual Behavior, Mar 17 2021. https://rd.springer.com/article/10.1007/s10508-021-01955-4

Abstract: In their Target Article, Davis and Arnocky (2020) suggest that evolutionary theories of mate preferences can contribute to our understanding of why appearance-enhancement behaviors are seemingly ubiquitous. We support their argument that an interdisciplinary approach, in which evolutionary and other perspectives are fully integrated, will give us a more complete understanding of appearance-enhancement behaviors. We also agree that evolutionary theories of mate preferences have the potential to provide new insights into why such behaviors are so common. Here, we use the literature on women’s facial attractiveness to highlight an important limitation of this argument: uncertainty about precisely what is signalled by physical attractiveness.

Check also Marcinkowska, Urszula M., Benedict C. Jones, and Anthony J. Lee. 2021. “Self-rated Attractiveness Predicts Preferences for Sexually Dimorphic Facial Characteristics: Evidence from a Culturally Diverse Sample.” PsyArXiv. March 10. https://www.bipartisanalliance.com/2021/03/self-rated-attractiveness-predicts.html

Our results suggest that compressing a neural circuit through the "genomic bottleneck" serves as a regularizer, enabling evolution to select simple circuits that can be readily adapted to important real-world tasks

Encoding innate ability through a genomic bottleneck. Alexei Koulakov, Sergey Shuvaev, Anthony Zador. bioRxiv Mar 16 2021. https://doi.org/10.1101/2021.03.16.435261

Abstract: Animals are born with extensive innate behavioral capabilities, which arise from neural circuits encoded in the genome. However, the information capacity of the genome is orders of magnitude smaller than that needed to specify the connectivity of an arbitrary brain circuit, indicating that the rules encoding circuit formation must fit through a "genomic bottleneck" as they pass from one generation to the next. Here we formulate the problem of innate behavioral capacity in the context of artificial neural networks in terms of lossy compression of the weight matrix. We find that several standard network architectures can be compressed by several orders of magnitude, yielding pre-training performance that can approach that of the fully-trained network. Interestingly, for complex but not for simple test problems, the genomic bottleneck algorithm also captures essential features of the circuit, leading to enhanced transfer learning to novel data sets. Our results suggest that compressing a neural circuit through the genomic bottleneck serves as a regularizer, enabling evolution to select simple circuits that can be readily adapted to important real-world tasks. The genomic bottleneck also suggests how innate priors can complement conventional approaches to learning in designing algorithms for artificial intelligence.

Our findings challenge the role of social media in the creation of like-minded discussion; instead, we should look to the role of individual attributes, such as personality traits

The Role of Personality in Political Talk and Like-Minded Discussion. Shelley Boulianne, Karolina Koc-Michalska. The International Journal of Press/Politics, March 17, 2021. https://doi.org/10.1177/1940161221994096

Abstract: Political discussion is a key mechanism for the development of reasoned opinions and political knowledge, but online political discussion has been characterized as uncivil, intolerant, and/or ideologically homogeneous, which is detrimental to this development. In this paper, we examine the role of personality in various forms of political talk—online and offline—as well as like-minded discussion. Based on a 2017 survey conducted in the United Kingdom, United States, and France, we find that people who are open-minded and extraverted are more likely to engage in political talk but less likely to engage in like-minded discussion. Individuals who are older, less educated, introverted, and conscientious are more likely to find themselves in like-minded discussions, both online and on social media. Like-minded discussion is rare; personality, rather than ideology, predicts whether people engage in this form of political talk in online and offline modes. Our findings challenge the role of social media in the creation of like-minded discussion. Instead, we should look to the role of individual attributes, such as personality traits, which create a disposition that motivates the use of social media (and offline networks) to cultivate like-minded discussion.

Keywords: Big Five personality traits, political discussion, political talk, like-minded discussion, echo chamber

Discussion

This paper examines how personality affects the filtering process related to political discussion. Personality impacts the propensity to discuss politics, use social media, and engage in like-minded discussion on social media. Several steps are required to understand like-minded discussion on social media: (1) consider the biases in who talks politics (81.57 percent of our pooled sample, as per Table 2), (2) consider the filtering of social media adoption (76.82 percent of our pooled sample), (3) consider the subset of people who talk politics on social media (43.99 percent of our pooled sample of social media users), and (4) consider the few people who engage in like-minded discussion (9.41 percent of a pooled sample of social media talkers). Approximately one in ten respondents engages in like-minded discussion; this incidence rate is consistent for offline and online forms. So we ask, what is the role of personality throughout this filtering process? This question is answered with our annotation of Figure 2.

[Figure 2. Summary of findings about personality and political discussion.]

Note. Diagonal-dashed arrows are filtering arrows and straight arrows depict causal effects among key variables in the analysis. O = openness, C = conscientious, Ex = extraversion, A = agreeable, Es = emotional stability.

Openness impacts whether an individual talks politics online and offline and whether they use social media. The filtering process has three stages. In the first stage, people who are open-minded are more likely to talk politics (any mode). In the second stage, people who are open-minded adopt social media use. In the third stage, people who are open-minded are less likely to engage in like-minded discussion. The coefficient did not reach statistical significance at the p < .05 level. Openness has a stronger and more consistent impact than ideology. The existing literature (Table 1) features ten tests of the relationship between openness and political discussion. Of these, four tests for openness on political discussion are significant, which suggests a relationship but hardly offers conclusive results (Table 1). These other studies from the existing literature do not consider the mode of discussion and few consider personality and like-minded discussion. Yet, we offer consistent findings about the importance of openness using our pooled cross-national sample.

We find that extraversion is also important. As mentioned, the existing research features ten tests of the relationship between extraversion and political discussion of which five are significant (Table 1). Extraversion has mixed support related to political discussion in general; extraversion influences talk on social media, but not offline. However, extraversion is a strong and consistent predictor of like-minded discussion on social media and offline. In terms of understanding like-minded discussion on social media, extraversion seems to be the strongest and most consistent personality trait. We replicate this finding in the country-specific results.

Existing research (Table 1) suggests that agreeableness is important (four of ten tests are significant), yet the findings are not consistently positive or negative but rather highly divergent. In our study, agreeableness matters for social media adoption but does not offer direct effects on the likelihood of talking politics. However, as mentioned, assessing agreeableness poses challenges because this trait is strongly correlated with conscientiousness and extraversion (see prior literature review and Supplementary Information file). Correlation issues with these personality traits may pose a challenge when trying to determine their independent effects. We included all traits in our models to reflect existing research (Table 1).

Our paper distinguishes between offline discussion and online discussion through social media. Openness predicts both modes of discussion, suggesting the two modes might be combined into a single, hybrid discussion measure (Chadwick 2013). However, combining these modes would blur some important findings about social media and the role of personality in filtering social media-based discussion. In particular, extraversion and conscientiousness predict social media use, then social media-based discussion, then like-minded discussion on social media. The effects of these personality traits might disappear if the modes are combined into a single measure of political discussion as these measures do not have the same predictive value in relation to offline discussion (general). Also, age and political ideology predict online but not offline forms of discussion. Combining these modes would hide these ideological and age differences in patterns of participation. Age is a consistent predictor of online political discussion (Brundidge 2010; Evans and Ulbig 2012; Huber et al. 2019; Kim and Baek 2018; Stromer-Galley 2002). Finally, females are more likely to participate in offline political talk, but less likely to talk on social media (also see: Evans and Ulbig 2012; Huber et al. 2019; Stromer-Galley 2002). These gender differences would be missed in a combined measure of political discussion. All of these differences have implications with respect to the quality and representativeness of online discussion. We still have more research to do on this topic, given the low explained variance in our models as well as those models summarized in Table 1.

Like-minded discussion may have both positive and negative impacts. Mondak (2010: 115) explains that “conversations with like-minded others may offer reassurance and support, but such conversations do nothing to broaden the person's perspectives.” Discussions with people of differing viewpoints are expected to increase political tolerance (Nir 2017) and perhaps decrease attitude polarization (Grönlund et al. 2015; Mutz 2006). Personality shapes the propensity to engage in homogeneous discussion networks (Hibbing et al. 2011; Kim et al. 2013; Mondak et al. 2010). We have contributed to scholarship by testing the role of personality in an online discussion. Our findings suggest that like-minded discussion networks cannot be solely attributed to social media use. An individual's personality affects whether they use social media (Correa et al. 2010; Jenkins-Guarnieri et al. 2012; Ryan and Xenos 2011) and how they use social media. People who are introverted, close-minded, and conscientious will use social media to form discussion networks where their ideas will not be challenged. Indeed, when it comes to like-minded discussion, we find that personality matters more than political ideology.

As a final note, our data are limited to self-reports about political discussion—an issue that this field of research has addressed (Wojcieszak and Mutz 2009). We do not know if people truly abstain from political discussion, nor do we have an independently verified approach to measure the frequency of political discussion. Social media trace data would help to validate the estimates about frequency. However, social media data are limited for assessing like-minded discussion, as it is difficult to determine whether two discussion partners agree or disagree with each other's social media posts. For example, on Twitter, there is a “like” button but no “dislike” button. Facebook offers more nuances, albeit the “like” button is still the most popular response and does not suggest agreement so much as acknowledgment. Ideology is sometimes used as a proxy for this disagreement, but even ideological leanings are difficult to decipher in relation to the discussion of complex policy issues, such as immigration or the economy. Surveys are a valuable tool to supplement social media trace data as people can be asked about their agreement or disagreement with the topic. Future research should consider using a mixed-methods approach with a record of political discussion (such as social media trace data) as well as a survey of personality traits, policy positions, and reports about (dis)agreement. Our survey is an important contribution to the field, which has examined self-reports of offline discussion based on surveys or online discussion using social media trace data. We bridge these two modes but come to similar conclusions. Like-minded discussion is rare; personality, rather than ideology, predicts whether people engage in this form of political talk in online and offline modes.

Prior to proposing our research hypothesis and questions, we presented the findings of existing research. Research to date is based largely on American samples, yet international scholars have used the same theoretical claims for tests based on non-U.S. samples. Existing scholarship has not addressed whether we should expect cross-national differences in the relationship between personality and political discussion. As such, we proposed a research question, rather than a hypothesis. We find consistency in the importance of extraversion predicting like-minded discussion. Extraverts are less likely to engage in like-minded discussion. We replicate existing research about cross-national differences in political talk (Nir 2012; Vaccari and Valeriani 2018), but we offer new evidence about the importance of personality and perhaps culture in political discussion.