Microbiome differences in autism spectrum disorder may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD

Autism-related dietary preferences mediate autism-gut microbiome associations. Chloe X. Yap et al. Cell, Nov 11 2021. https://doi.org/10.1016/j.cell.2021.10.015

Highlights

• Limited autism-microbiome associations from stool metagenomics of n = 247 children

• Romboutsia timonensis was the only taxa associated with autism diagnosis

• Autistic traits such as restricted interests are associated with less-diverse diet

• Less-diverse diet, in turn, is associated with lower microbiome alpha-diversity

Summary: There is increasing interest in the potential contribution of the gut microbiome to autism spectrum disorder (ASD). However, previous studies have been underpowered and have not been designed to address potential confounding factors in a comprehensive way. We performed a large autism stool metagenomics study (n = 247) based on participants from the Australian Autism Biobank and the Queensland Twin Adolescent Brain project. We found negligible direct associations between ASD diagnosis and the gut microbiome. Instead, our data support a model whereby ASD-related restricted interests are associated with less-diverse diet, and in turn reduced microbial taxonomic diversity and looser stool consistency. In contrast to ASD diagnosis, our dataset was well powered to detect microbiome associations with traits such as age, dietary intake, and stool consistency. Overall, microbiome differences in ASD may reflect dietary preferences that relate to diagnostic features, and we caution against claims that the microbiome has a driving role in ASD.

Discussion

In this large ASD stool metagenomics study in which confounders were carefully considered, we found negligible evidence for direct associations between the stool microbiome and ASD diagnostic status, which was also the case for other neurodevelopmental traits (e.g., IQ-DQ, sleep problems). For ASD, there was limited evidence for associations with taxonomic diversity or microbiome-association index (b2; Figure 2), and only one differentially abundant species was robustly identified (Figure 3). These results were striking when compared to strong associations of microbiome composition with age, diet, and stool consistency (Figure 2). Importantly, we failed to replicate previously reported ASD-microbiome associations from human studies. Instead, we found evidence linking behaviors associated with the autism spectrum (e.g., repetitive-restricted behaviors or interests, sensory preferences, and social affect) to reduced dietary diversity, which, in turn, was associated with reduced microbiome diversity and looser stool consistency (Figure 4J). This putative model challenges suggestions from animal studies that the microbiome may be causally related to ASD-related traits (

Buffington et al., 2016

; 

Hsiao et al., 2013

; 

Sharon et al., 2019

). Our findings also stand at odds to the proliferation of experimental interventions and early clinical trials that propose to “treat” ASD by targeting the microbiome (

Kang et al., 2019

; 

Kang et al., 2017

).

In contrast to measures of microbiome composition, ASD was robustly and significantly linked to dietary variables, irrespective of covariates (Table S3). We found (1) that significant variance in ASD diagnosis was associated with diet but not the microbiome in the b2 analysis (Figure 2), (2) reduced meat intake in the ASD group (Figure S5), and (3) reduced dietary diversity in the ASD group despite significantly higher variance in dietary diversity (Figure 4A), which is consistent with the dietetics literature (

Panossian et al., 2020

; 

Schreck and Williams, 2006

) and some smaller ASD microbiome studies with dietary data (

Berding and Donovan, 2018

).

One rationale for the interest in the ASD microbiome is the frequent co-occurrence of gastrointestinal complaints (

Chaidez et al., 2014

; 

Kohane et al., 2012

; 

McElhanon et al., 2014

). In the absence of complete gastrointestinal complaint reporting, we analyzed stool consistency scores, with the caveat that it is unclear how this single-time point data reflects chronic conditions. Stool consistency appeared to be more proximal to taxonomic than dietary diversity, although we acknowledge that it is difficult to distinguish between a top-down (i.e., dietary and taxonomic diversity influencing downstream stool consistency) versus bottom-up (i.e., stool consistency being an upstream proxy) relationship. For the former, dietary restrictedness could plausibly affect gut ecology and taxonomic diversity, which in turn affects stool consistency. In relation to a bottom-up model, looser stool may indicate underlying food allergies or intolerances, which may be associated with deliberate (parental) dietary restriction to identify causative agents. Additionally, looser stool consistency reflects reduced gastrointestinal transit time and reduced colonic water reuptake (

Vandeputte et al., 2016

), which affects taxonomic diversity. As the narrow-sense heritability of gastrointestinal conditions that affect stool consistency (e.g., irritable bowel syndrome) are small (

Wu et al., 2021

), environmental contributions likely predominate over genetics (

Rothschild et al., 2018

).

Our results have important implications for understanding the role of the gut microbiome in ASD and other psychiatric traits. First, in relation to medical care, food selectivity among children on the autism spectrum is an important clinical concern. Food selectivity is related to avoidant/restrictive food intake disorder (ARFID; which is likely underdiagnosed despite affecting over 20% of autistic children [

Koomar et al., 2021

]) and can cause nutritional deficiencies among autistic children (

Zimmer et al., 2012

) to the extent that hospitalization and invasive measures such as enteral feeding are required (

Tang et al., 2011

). Our results also suggest that dietary quality is poorer in children on the spectrum (Methods S1). Given that elevated microbial diversity is robustly associated with improved health outcomes (

Valdes et al., 2018

), the association of ASD with poorer dietary quality and reduced dietary and taxonomic diversity underlines the importance of dietary and nutritional interventions in this population. Second, our results have implications for the interpretation of cause and effect in relation to diet in microbiome analyses in psychiatric conditions. There is growing interest in the contribution of diet and the microbiome to psychiatric traits (e.g., depression [

Dash et al., 2015

; 

Molendijk et al., 2018

]), but our results emphasize the need to consider the (arguably more intuitive) impact of behavior on the microbiome (

Jacka et al., 2015

). These results add to other reports of diet driving microbiome associations with health (

Claesson et al., 2012

).

For future microbiome studies, we emphasize the importance of collecting detailed dietary data (recent examples [

Asnicar et al., 2021

; 

Wang et al., 2021

]), particularly for ASD and other neuropsychiatric traits with plausible co-variation of diet with diagnosis or treatment. We advocate for larger sample sizes to ensure that results are robust to sampling effects and to identify subtler microbiome associations. We also recommend higher-resolution metagenomics technology and expanded databases since more granular taxonomic measures of microbiome composition were more sensitive (Table S1), gene-level ORMs explained more variance for some traits (Table S1), power to detect associations was weaker with the MetaPhlAn2/NCBI pipeline (Methods S1), and because taxonomic and functional datasets may capture complementary aspects of the microbiome (Figures S1 and S3).

In conclusion, we found negligible direct associations between ASD and the gut microbiome in contrast to strong associations with other phenotypes such as age, dietary variables, and stool consistency. Instead, we find evidence that restricted dietary diversity and poorer quality—which is associated with specific ASD features such as restrictive-repetitive behaviors—is a significant mediator of taxonomic diversity, and in turn, stool consistency. Our results are consistent with an upstream role for ASD-related behaviors and dietary preferences on the gut microbiome and are contrary to claims of the microbiome having a major (or causal) role in ASD.

 Limitations of the study

First, this study did not have a longitudinal design, so we cannot rule out microbiome contributions prior to ASD diagnosis. Second, although this is to our knowledge the largest metagenomics study of the ASD stool microbiome to date, there may nonetheless be sampling biases that require larger studies to overcome (

Rothschild et al., 2020

). Third, this study used stool samples as a gut microbiome proxy, which may not accurately represent the more difficult-to-access mucosal microbiome (

Shanahan et al., 2016

). Fourth, data on antibiotic intake in this cohort were not systematically collected and so could not be rigorously accounted for other than through exclusion in sensitivity analyses. Fifth, the gold-standard differential abundance analysis relied on per-feature tests that do not reflect the interactions and non-independence that occurs within an ecological or metabolic context. Finally, we await the emergence of datasets with comparable study design, consideration of confounders, and depth of phenotypic and metagenomics data for replication of these results.

Individuals with higher self-esteem had more lifelike and accurate images of themselves in their mind's eye

The Self in the Mind’s Eye: Revealing How We Truly See Ourselves Through Reverse Correlation. Lara Maister et al. Psychological Science, November 11, 2021. https://doi.org/10.1177/09567976211018618

Abstract: Is there a way to visually depict the image people “see” of themselves in their minds’ eyes? And if so, what can these mental images tell us about ourselves? We used a computational reverse-correlation technique to explore individuals’ mental “self-portraits” of their faces and body shapes in an unbiased, data-driven way (total N = 116 adults). Self-portraits were similar to individuals’ real faces but, importantly, also contained clues to each person’s self-reported personality traits, which were reliably detected by external observers. Furthermore, people with higher social self-esteem produced more true-to-life self-portraits. Unlike face portraits, body portraits had negligible relationships with individuals’ actual body shape, but as with faces, they were influenced by people’s beliefs and emotions. We show how psychological beliefs and attitudes about oneself bias the perceptual representation of one’s appearance and provide a unique window into the internal mental self-representation—findings that have important implications for mental health and visual culture.

Keywords: self-representation, body, appearance, reverse correlation, personality, self-face, open data

Discussion

We investigated how we see ourselves in our mind’s eye by creating visual images of individual participants’ mental representations of both their faces and their body shapes in a data-driven, unconstrained way, minimizing participant biases and experimenter assumptions. This technique produced rich, holistic, and multidimensional visual representations of the face and body, which we found not only carried accurate information about physical appearance but also provided novel insights into the way in which participants’ thoughts and feelings about themselves can color their self-image.

We observed clear interactions between the physical and psychological aspects of the self: Self-portraits of both the face and the body were significantly related to higher level, more abstract self-beliefs and attitudes. In Experiment 1, representations of one’s facial appearance were influenced by beliefs regarding one’s personality traits; for example, if a participant believed that they were highly extraverted, they also held an internal representation of their face that had exaggerated stereotypically extraverted facial features compared with their true appearance. In Experiment 2, we demonstrated similar results for perceptual representations of body shape: Participants with negative attitudes toward their bodies also held visual representations of their body’s physical appearance as wider and typical peers as slimmer, compared with participants who had more positive attitudes.

Until now, there has been little investigation of the interaction between physical and psychological selves, and most of the work that has been done has focused on the bottom-up effects of multisensory and sensorimotor contingencies on higher-level psychological self-representations (Preston & Ehrsson, 2014). Our work uniquely focuses on self-representations stored in long-term memory to point to a close, interactive relationship between physical and psychological representations of the self, consistent with an interactive hierarchical model of self-representation (as proposed by Sugiura, 2013). Higher level self-beliefs and attitudes may influence the perceptual quality of the self-portraits (via a top-down modulation during the reconstruction of these images; see Kosslyn, 2005), but conversely, the perceptual features of the physical self-representation might also lead to congruent inferences about one’s self-beliefs and attitudes. Indeed, evidence from studies on social perception supports a bidirectional causal relationship for our representations of others (Dotsch et al., 2008; Todorov et al., 2015); therefore, a similar bidirectional relationship with regard to self-representations may also be likely.

Although the results with regard to the relationship between physical and psychological self-representations were similar for faces and bodies, there were interesting differences. Participants’ representations of their facial appearance were clearly related to their real facial characteristics, showing a significant level of self-specificity. Classification studies, both using human participants and simulated using a face-recognition algorithm, confirmed that identity could be correctly classified from the self-portraits at well-above-chance levels. In contrast, participants’ perceptual representations of their bodies were less related to real body characteristics (e.g., actual body size) and were more strongly influenced by affective attitudes toward the self. This is consistent with previous evidence using single-dimension measures of body parts (Ben-Tovim et al., 1990) and brings into question the wide literature attempting to characterize perceptual body representations in eating disorders in terms of overestimation or underestimation biases (for a review, see Mölbert et al., 2017). However, it will be important to replicate the findings of both experiments using larger samples of more diverse participants before drawing conclusions. The generalizability of the present study may be limited. In Experiment 1, only young Caucasian adults were tested, and therefore it is necessary to follow up with studies using a wider range of ethnicities. Furthermore, in Experiment 2, only young adult women were tested, and their body size may have been relatively homogeneous compared with the general population.

Interestingly, individual differences in objective accuracy of the facial self-portraits were correlated with self-esteem, specifically with regard to social confidence. The higher an individual’s social self-esteem, the more objectively accurate their self-portrait was. This raises interesting considerations regarding the causal role of social interaction in the development and maintenance of self-representations. Social interactions are an important source of information about our appearance, via feedback on our appearance and via social comparisons (Cash et al., 1983). Therefore, individuals with higher social self-esteem may have engaged in more frequent, close social interactions and thus received more social input about their appearance, leading to more accurate self-perception. Alternatively, individuals with more accurate perception of their appearance may also have smoother, more reciprocal, and more predictable social relationships, leading to greater social confidence. For example, having an accurate perception of one’s own attractiveness may lead to more successful romantic interactions and a lower chance of being rebuffed by someone poorly matched (see Le Lec et al., 2017), leading to higher social self-esteem. Both of these potential explanations appeal to a long-term relationship between self-esteem and the development of an accurate self-face representation. However, it is important to note that in our study, we assessed state self-esteem rather than trait self-esteem. Although it is likely that state and trait self-esteem measures are highly correlated (e.g., see Heatherton & Polivy, 1991), future research may explore whether this finding holds for more stable aspects of self-esteem.

Our results are consistent with the findings of a very recent study, which also used the reverse-correlation technique to create visual self-face representations (Moon et al., 2020). In this study, links were found between the valence of the self-face representations generated, as rated by external observers, and various self-reported traits. Self-esteem, explicit self-evaluation, and extraversion were found to be linked to more positive or pleasant-appearing self-portraits, and social anxiety was related to more negative or unpleasant-appearing self-portraits. The authors concluded that the valence of self-face representations created in this manner was able to reflect the attitude toward self. In the present study, consistent with Moon et al.’s findings, our results also showed a significant association between self-reported psychological traits and the physical features of the self-face representation. However, our results further refine our understanding of this relationship by demonstrating that self-reported personality traits were not merely linked with the perceptual valence of self-face representations, as in Moon et al.’s study, but that individual personality traits were linked to specific facial configurations in the self-portraits that were recognizable as such by independent raters.

Our study further extends existing knowledge in several key ways. First, although Moon et al. (2020) measured participants’ perceptions of self-similarity with their own self-portraits, no work has yet been done to explore the actual accuracy of self-representations or to provide a well-controlled, unbiased assessment of their links to self-beliefs and attitudes. Here, we confirmed the validity of the reverse-correlation method in self-face representation research, demonstrating that the resulting images contain enough visual information to support recognition using subjective ratings from an independent sample of raters as well as objectively using simulated experiments implementing a face-recognition algorithm. Furthermore, when exploring whether these self-face representations are influenced by higher level self-processing, we controlled for real facial features, which is crucial to avoid confounds and to provide a valid, strict test of our hypothesis. Finally, we extended our investigation to consider not only face representations but also body shapes, which enriched and generalized our findings to lend support to a broader mechanism whereby beliefs and attitudes influence perceptual body representations.

In this study, we used a combination of objective, algorithm-based techniques and subjective personality ratings from human observers to analyze both the self-portraits and real photographs. It is possible that the human ratings of the real photographs may have been informed by superficial features of the faces, such as makeup, facial hair, and grooming habits, despite the participants providing the ratings being instructed to ignore such features. However, it is important to note that the effects of this potential source of information could not explain the key results reported here. Such effects would serve only to increase the correlation found between the personality ratings of participants’ real faces and their self-reported personalities. Importantly, it could not alter the relationship between the personality ratings of the self-portraits and the self-reported personality ratings, which is key for our hypothesis, because superficial features such as facial hair and makeup were not represented in the reverse-correlation images. This issue further reiterates the importance of carefully controlling for participants’ real facial ratings, which we ensured was done in each key analysis.

Both the approach we used to produce the self-portraits and our findings are highly relevant to our understanding of clinical disorders of body image, such as anorexia nervosa and body dysmorphia. Previous studies into these disorders have normally focused on online perception of the body or have used distorted images of the patients’ own bodies as stimuli, which did not allow for unbiased measurement (Smeets et al., 1999). Our approach could be used as a unique, direct method of assessing distortions in visual memory in these patients, allowing us to reveal whether they stem from higher level self-beliefs and attitudes or even a disorder in the link between these attitudes and the physical self-representation. This approach will also allow us to compare the effects of different treatments (e.g., those targeting perceptual distortions and those targeting emotional or cognitive aspects of the disorder) as well as assess the effects of treatment across time.

In conclusion, we present a novel way to visually depict how people see themselves in their mind’s eye and, in doing so, revealed visual clues to people’s deeply held self-beliefs and attitudes. Our mental images of our own appearance are fundamental to our understanding of some of the most severe mental disorders that are clustered under the term of body-image disorders. In addition, at a time when our culture is powered by images at an unprecedented level, and our obsession with our own image is evidenced in our social media use (Storr, 2018), our approach and the novel insights presented here pave the way for future explorations, in a data-driven, unconstrained, and richly detailed way, of how we mentally see ourselves.

Novel projects of scientific & tech innovation: We found causal evidence of a negativity bias, where evaluators lower their scores by more points after seeing scores more critical than their own rather than raise them after seeing more favorable scores

Conservatism Gets Funded? A Field Experiment on the Role of Negative Information in Novel Project Evaluation. Jacqueline N. Lane , Misha Teplitskiy , Gary Gray, Hardeep Ranu, Michael Menietti , Eva Guinan , Karim R. Lakhani. Management Science, Oct 28 2021. https://doi.org/10.1287/mnsc.2021.4107

Abstract: The evaluation and selection of novel projects lies at the heart of scientific and technological innovation, and yet there are persistent concerns about bias, such as conservatism. This paper investigates the role that the format of evaluation, specifically information sharing among expert evaluators, plays in generating conservative decisions. We executed two field experiments in two separate grant-funding opportunities at a leading research university, mobilizing 369 evaluators from seven universities to evaluate 97 projects, resulting in 761 proposal-evaluation pairs and more than $250,000 in awards. We exogenously varied the relative valence (positive and negative) of others’ scores and measured how exposures to higher and lower scores affect the focal evaluator’s propensity to change their initial score. We found causal evidence of a negativity bias, where evaluators lower their scores by more points after seeing scores more critical than their own rather than raise them after seeing more favorable scores. Qualitative coding of the evaluators’ justifications for score changes reveals that exposures to lower scores were associated with greater attention to uncovering weaknesses, whereas exposures to neutral or higher scores were associated with increased emphasis on nonevaluation criteria, such as confidence in one’s judgment. The greater power of negative information suggests that information sharing among expert evaluators can lead to more conservative allocation decisions that favor protecting against failure rather than maximizing success.

There is a general gender difference in paraphilic interests, such that men report more interest (and greater engagement) in a variety of paraphilic behaviors

Sex Drive as a Possible Mediator of the Gender Difference in the Prevalence of Paraphilic Interests in a Nonclinical Sample. Enya Levaque, Samantha J. Dawson, Cynthia Wan & Martin L. Lalumière . Archives of Sexual Behavior, Nov 8 2021. https://link.springer.com/article/10.1007/s10508-021-02074-w

Abstract: There is a general gender difference in paraphilic interests, such that men report more interest (and greater engagement) in a variety of paraphilic behaviors. Using a nonclinical sample, Dawson et al. (Sexual Abuse, 28(1):20–45, 2016, https://doi.org/10.1177/1079063214525645) found that the gender difference in paraphilic interests was eliminated when scores on measures of sex drive were used as mediators. However, their measures of sex drive were about more than just sex drive and included a measure of hypersexuality (i.e., distress, perceived lack of control, and problematic consequences of one’s sexuality). This study had two aims: to replicate Dawson et al.’s mediation results (using the same measures and scoring methods), and to discern the effect of sex drive itself (by replacing their measure of hypersexuality with a measure of sex drive). A nonclinical sample of 517 men and 615 women completed an online questionnaire. As expected, men reported less repulsion than women for most paraphilic themes. The gender difference in paraphilic interests was reduced (but not eliminated) both when reproducing Dawson et al.’s analysis and when examining a mediation model focused on sex drive specifically. The same results were obtained when examining the paraphilic interest with the largest gender difference (i.e., voyeurism). A full mediation effect was obtained in an unplanned supplementary analysis using a factor score (derived from eight measures) putatively assessing sex drive. While the main findings are consistent with Dawson et al.’s conclusions that sex drive is a possible mediator, they also suggest that other factors need to be considered to help explain the gender difference in the prevalence of paraphilic interests.

55 cultural groups from 33 nations: Those who saw themselves as more connected to others and those who emphasized commitment to others above self-interest were more likely to endorse the value of looking after the environment

Self-Construals and environmental values in 55 cultures. Hamish Duff et al. Journal of Environmental Psychology, November 7 2021, 101722. https://doi.org/10.1016/j.jenvp.2021.101722

Highlights

• Past research has noted similarities between self–other and self–nature relations.

• We report correlations among seven self-construal dimensions and environmental values.

• Cross-cultural findings confirmed reliable interdependence–environmentalism relations.

• Greater connection and commitment to others linked to environmental values.

• Consistency versus variability was the only independent pole with positive correlation.

• Self-reliance versus dependence on others was unrelated to environmental values.

• Other ways of being independent/interdependent showed inconsistent correlations.

Abstract: Environmentalism is influenced by views of the self. In past research, individuals who saw themselves as more interdependently connected to others expressed greater environmental concern than those who saw themselves as more independent from others. Yet, cross-cultural evidence is limited. In this pre-registered study, we tested how seven ways of being interdependent or independent correlated with environmental values among 7279 members of 55 cultural groups from 33 nations. Supporting our predictions, environmental values were strongly associated with several forms of interdependent self-construal, supporting parallels between self–other and self–nature relations. Specifically, two interdependent forms of self-construal showed consistent cross-cultural correlations: those who saw themselves as more connected to others and those who emphasized commitment to others above self-interest were more likely to endorse the value of looking after the environment. Extending previous conceptions, one way of being independent correlated consistently with environmental values: those who saw themselves as consistent across contexts were also more likely to endorse environmental values. Multilevel moderation analysis indicated that commitment to others had stronger correlations with environmental values in nations with greater environmental performance and national development. We conclude that improving social connectedness and cohesion, alongside the protection of natural ecosystems, may be imperative for tackling the global climate crisis.

Keywords: Self-construalEnvironmentalismEnvironmental valuesCross-cultural

Men more highly value same-sex friends who are physically formidable, possess high status, possess wealth, & afford access to potential mates; women more highly value friends who provide emotional support, intimacy, & useful social information

Sex differences in friendship preferences. Keelah E.G. Williams et al. Evolution and Human Behavior, November 10 2021. https://doi.org/10.1016/j.evolhumbehav.2021.09.003

Abstract: Friendships can help us solve a number of challenges, increasing our welfare and fitness. Across evolutionary time, some of the many challenges that friendships helped to solve may have differed between men and women. By considering the specific and potentially distinct recurrent problems men's and women's friendships helped them solve, we can derive predictions about the qualities that would have made men's and women's same-sex friends ideal partners. This logic leads to several predictions about the specific friend preferences that may be differentially prized by men and women. Across three studies (N = 745) with U.S. participants—assessing ideal hypothetical friends, actual friends, and using a paradigm adapted from behavioral economics—we find that men, compared to women, more highly value same-sex friends who are physically formidable, possess high status, possess wealth, and afford access to potential mates. In contrast, women, compared to men, more highly value friends who provide emotional support, intimacy, and useful social information. Findings suggest that the specific friendship qualities men and women preferred differed by sex in ways consistent with a functional account of friendship.

Keywords: FriendshipSex differencesEvolutionary psychologyFriend preferences

Adaptation to incentives: Proposed Child Tax Credit Expansion would lead 1.5 million workers (2.6% of all working parents) to exit the labor force; child poverty would only fall by 22% (instead of estimated 34pct) & deep child poverty would not fall at all

Corinth, Kevin and Meyer, Bruce and Stadnicki, Matthew and Wu, Derek, The Anti-Poverty, Targeting, and Labor Supply Effects of the Proposed Child Tax Credit Expansion (October 7, 2021). University of Chicago, Becker Friedman Institute for Economics Working Paper No. 2021-115. SSRN: http://dx.doi.org/10.2139/ssrn.3938983

Abstract: The proposed change under the American Families Plan (AFP) to the Tax Cuts and Jobs Act (TCJA) Child Tax Credit (CTC) would increase maximum benefit amounts to $3,000 or $3,600 per child (up from $2,000 per child) and make the full credit available to all low and middle-income families regardless of earnings or income. We estimate the anti-poverty, targeting, and labor supply effects of the expansion by linking survey data with administrative tax and government program data which form part of the Comprehensive Income Dataset (CID). Initially ignoring any behavioral responses, we estimate that the expansion of the CTC would reduce child poverty by 34% and deep child poverty by 39%. The expansion of the CTC would have a larger anti-poverty effect on children than any existing government program, though at a higher cost per child raised above the poverty line than any other means-tested program. Relatedly, the CTC expansion would allocate a smaller share of its total dollars to families at the bottom of the income distribution—as well as families with the lowest levels of long-term income, education, or health—than any existing means-tested program with the exception of housing assistance. We then simulate anti-poverty effects accounting for labor supply responses. By replacing the TCJA CTC (which contained substantial work incentives akin to the EITC) with a universal basic income-type benefit, the CTC expansion reduces the return to working at all by at least $2,000 per child for most workers with children. Relying on elasticity estimates consistent with mainstream simulation models and the academic literature, we estimate that this change in policy would lead 1.5 million workers (constituting 2.6% of all working parents) to exit the labor force. The decline in employment and the consequent earnings loss would mean that child poverty would only fall by 22% and deep child poverty would not fall at all with the CTC expansion.

Caveats

A few caveats are in order. While our baseline estimate is that employment will decline by 1.5 million adults based on the midpoint of ranges used in past simulations and the central tendency of literature surveys, both lower and higher changes are predicted by other elasticities in the literature. Since we rely on elasticities from the literature rather than estimate a full structural model, we would need other information to allocate the average tendencies implied by elasticities to particular individuals. For example, we do not know whether a one percent decline in average hours implies a ten percent decline for one in ten people or a one percent decline for every worker.

Similarly, we would need a more sophisticated model than the one we employ to consider the separate incentives of both spouses in a couple. These complications are avoided in our modeling of the work/nonwork decisions for single worker families since average tendencies imply probabilistic choices that are easily modeled. As a result, we focus only on the work/nonwork decision, not incorporating the reduction in hours that would be expected for those who remain in the workforce due to the increase in marginal tax rates along the previous phase-in and over the new phase-out of the CTC. This understatement of the work response is likely offset to some extent by our simplified work decision of couples, taking them both to stop working or neither to stop working. In fact, the employment response for couples should be spread across a larger number of families, some of whom would have only one spouse leave the labor market. Since the loss of one out of two low-income earners from a family is likely to lead a family to be below the poverty line but not the deep poverty line, the implication of our simplification is that the child poverty reduction of the AFP CTC has likely been overstated, but the deep child poverty reduction understated. As the large majority of our response comes from single worker families, even assuming no response of dual-earner couples as an extreme would leave intact the large majority of the behavioral response we estimate. At least 83 percent of the families that experience a drop in earnings in our simulations have only one worker and are unaffected by this issue.39F 40

Long-Run Effects

Potential long-run effects of the CTC expansion are important to consider alongside shortrun effects. Increased support for low-income children could improve their long-run outcomes. Children’s access to food stamps in the 1960s and 1970s led to improved outcomes when they became adults, including higher earnings (though not increased employment), better health, less incarceration and less dependence on welfare programs (Hoynes, Schanzenbach, and Almond 2016; Bitler and Figinski 2019; Bailey et al. 2020). Much of this evidence comes from a period when other safety net programs were much less generous than current aid, so the marginal effects might be lower today. Larger EITC payments for children have increased their educational attainment and their employment and earnings as adults (Bastian and Michelmore 2018). In that case, the policy being examined is a combination of more income and higher employment. The incremental CTC could also affect behavior in less favorable ways, for example by changing rates of marriage or divorce. Some of the most methodologically sound research on this topic has found large effects of unconditional aid on single parenthood (Grogger and Bronars 2001). Consistent with this microdata evidence, the share of children with a single parent stabilized and then reversed after welfare reform, reversing a more than thirty-year trend.40F 41 Single parenthood has been found to lead, for example, to lower levels of educational attainment and higher incarceration rates of children in the long run (Hoffman and Maynard 2008).  

Resting heart rate as biological correlate of antisocial spectrum behavior: Effect sizes are largest for the most violent offenders & for psychopathy, while they are smaller for physical aggression, laboratory aggression, & antisocial personality disorder

Heart Rate and Skin Conductance Associations with Physical Aggression, Psychopathy, Antisocial Personality Disorder and Conduct Disorder: An Updated Meta-Analysis. Peter C. de Looff et al. Neuroscience & Biobehavioral Reviews, November 10 2021. https://doi.org/10.1016/j.neubiorev.2021.11.003

Highlights

• Resting heart rate remains the best replicated biological correlate of antisocial spectrum behavior.

• Physiological measures of heart rate and skin conductance might be used to differentiate between (and within) types of antisocial spectrum behavior based on the experimental task and analysis type (rest, task, and reactivity).

• Physiological measures of heart rate and skin conductance might be used to aid in diagnosing subtypes of mental health disorders as was evident from the differential effect sizes found for psychopathy and antisocial personality disorder for these are typically represented as similar constructs.

• Effect sizes are largest for the most violent offenders and for psychopathy, while they are smaller for physical aggression, laboratory aggression, and antisocial personality disorder.

Abstract: The associations between physiological measures (i.e., heart rate and skin conductance) of autonomic nervous system (ANS) activity and severe antisocial spectrum behavior (AB) were meta-analyzed. We used an exhaustive partitioning of variables relevant to the ANS–AB association and investigated four highly relevant questions (on declining effect sizes, psychopathy subscales, moderators, and ANS measures) that are thought to be transformative for future research on AB. We investigated a broad spectrum of physiological measures (e.g., heart rate (variability), pre-ejection period) in relation to AB. The search date for the current meta-analysis was on January 1st, 2020, includes 101 studies and 769 effect sizes. Results indicate that effect sizes are heterogeneous and bidirectional. The careful partitioning of variables sheds light on the complex associations that were obscured in previous meta-analyses. Effects are largest for the most violent offenders and for psychopathy and are dependent on the experimental tasks used, parameters calculated, and analyses run. Understanding the specificity of physiological reactions may be expedient for differentiating between (and within) types of AB.

Keywords: autonomic nervous systemantisocial behavioraggressive behaviorpsychopathymeta-analysisheart rateelectrodermal activity

Pets and Politics: Do Liberals and Conservatives Differ in Their Preferences for Cats Versus Dogs?

Pets and Politics: Do Liberals and Conservatives Differ in Their Preferences for Cats Versus Dogs? Chantelle Ivanski, Ronda F. Lo, Raymond A. Mar. Collabra: Psychology (2021) 7 (1): 28391. Nov 10 2021. https://doi.org/10.1525/collabra.28391

Abstract: Liberals and conservatives are perceived to disagree on most aspects of life, even seemingly trivial things like pet choice. Although the question of whether liberals and conservatives differ in their liking for cats and dogs has been sporadically investigated, few peer-reviewed reports exist, results are mixed, and most reports examine this topic indirectly. In this registered report we employed a large existing dataset to examine whether political identity predicts liking of cats and dogs, and a preference for one over the other. Self-reported political identity was used to predict explicit evaluations of both pets, in addition to performance on an Implicit Association Test (IAT) measuring pet preference. Greater conservativism predicted more negative evaluations of cats and an overall preference for dogs over cats, even after controlling for relevant demographics.

Keywords:political identity, individual differences, cats and dogs, pet preference

Discussion

In line with our hypotheses, conservativism is related to an overall preference for dogs over cats. Further, consistent with our overall reasoning (though not explicitly hypothesized), conservativism is also related to a negative evaluation of cats. These relationships remain even after controlling for relevant demographic information (i.e., age, gender, income, and ethnicity). Although people across the political spectrum show a greater liking for dogs overall (see Table 3), those who tend to be more conservative show less of an explicit liking for cats and have a stronger liking for dogs relative to cats. A similar pattern of results was seen with the results of the IAT score, with conservatives having a more positive implicit evaluation of dogs relative to cats. Our mediation analysis found evidence that RWA mediated the relationship between political identity and cat evaluations, and the relationship between political identity and a preference for dogs over cats (no mediation was observed for evaluations of dogs). But Openness to Experience and SDO did not mediate any of the relationships between political identity and pet preferences. Importantly, however, the magnitude of these effects was small, with a one unit change in political identity (on a 7-point scale) predicting about a 1% to 2% change in pet evaluations and preferences. This is to be expected, as pet preference is likely a rather distal reflection of other, more specific, traits that are captured indirectly by political identity.

The question of whether pet preferences coincide with differences in political identity continues to attract great public interest. In fact, after the 2020 federal election in the US, articles were written about how then-president-elect Biden was hoping to unite the country and “[bridge] the chasm between the nation’s cat people and dog lovers” by adopting a cat in addition to bringing his two dogs when moving into the White House (Luscombe, 2020). Though primarily meant to amuse, this anecdote does illustrate how the divide between cat and dog people is often associated with political divides. Our study provides the first direct and preregistered evidence that political identity is indeed associated with pet preferences, with respect to cats and dogs.

Our results are also consistent with much of the extant research on this topic. Cat ownership is higher in more liberal states (Bratskeir, 2016) and voting for McCain in 2008 (the conservative candidate) was related to state-level ownership of dogs, fish, horses, ferrets, and rodents, but not cats (Mutz, 2010). Interestingly, however, past findings associating liberalism with a liking for cats deviates from our own examination of state-level data, which found that cat ownership was not statistically significantly associated with voting for Trump.

Although the current research demonstrates that political identity predicts cat and dog preferences, the goal of this work is not to increase the already large divide between political partisans. In fact, pets may actually help bring together people of different political stripes. In a 2020 survey of cat and dog owners, for example, 64% of respondents reported that they would be more likely to talk to a person from a different political party if the person had a pet (Banfield Pet Hospital, 2020). In addition, knowing the other person has a pet had helped 45% of participants end an argument with those with differing political opinions (Banfield Pet Hospital, 2020).

Limitations and future directions

The main limitation of the present study was the large amount of missing data, an unavoidable outcome of the study design over which we had no control. Because our analyses were preregistered before we had an opportunity to see the actual data, we did not know how many participants completed each component until after pre-registration. As a result, some of the analyses we pre-registered proved to be too underpowered to be reliable (i.e., exploration of potential mediators and extreme scores). This is indeed unfortunate, as these analyses would have helped us to answer many interesting questions. Future research remains necessary to examine whether certain traits mediate the relationship between political identity and pet ownership. A second limitation is the measure of political identity employed in these archival data, which was a single item. Employing several items can help reduce measurement error and also allow for a greater breadth of construct coverage. Thus, studies designed to examine this question should include more items to measure political identity. Finally, the current study employed a cross-sectional design, making it difficult to make causal claims about the nature of this relationship between political identity and pet preferences.

In this work, we report the experimental realization of a zero-knowledge protocol involving two separated verifier–prover pairs; security is enforced via the physical principle of special relativity

Experimental relativistic zero-knowledge proofs. Pouriya Alikhani, Nicolas Brunner, Claude Crépeau, Sébastien Designolle, Raphaël Houlmann, Weixu Shi, Nan Yang & Hugo Zbinden. Nature volume 599, pages 47–50 (2021). Nov 3 2021. https://www.nature.com/articles/s41586-021-03998-y

Abstract: Protecting secrets is a key challenge in our contemporary information-based era. In common situations, however, revealing secrets appears unavoidable; for instance, when identifying oneself in a bank to retrieve money. In turn, this may have highly undesirable consequences in the unlikely, yet not unrealistic, case where the bank’s security gets compromised. This naturally raises the question of whether disclosing secrets is fundamentally necessary for identifying oneself, or more generally for proving a statement to be correct. Developments in computer science provide an elegant solution via the concept of zero-knowledge proofs: a prover can convince a verifier of the validity of a certain statement without facilitating the elaboration of a proof at all1. In this work, we report the experimental realization of such a zero-knowledge protocol involving two separated verifier–prover pairs2. Security is enforced via the physical principle of special relativity3, and no computational assumption (such as the existence of one-way functions) is required. Our implementation exclusively relies on off-the-shelf equipment and works at both short (60 m) and long distances (≥400 m) in about one second. This demonstrates the practical potential of multi-prover zero-knowledge protocols, promising for identification tasks and blockchain applications such as cryptocurrencies or smart contracts4.

Introduction.

In a foreign city where you know absolutely no one, you go to an automatic teller machine to obtain a handful of local cash. You have never heard of the bank owning that teller machine, yet when requested for your Personal Identification Number to obtain money you blindly provide it. No joke, you give away that super unique information to a complete stranger. But why? Because of the cash you get in return? There is actually zero solid reason to trust that teller machine. You should never have to give away this private information to anyone at all! But how could we prove who we are without giving away such a secret piece of data? The idea behind zero-knowledge proofs was born in the middle of the 1980’s [1] and formalises the possibility to demonstrate knowledge of a secret information without divulging it. A natural application is the task of identification, where a user can demonstrate their identity via the knowledge of a secret proof of a mathematical statement they created and published. A well-known example is the RSA cryptosystem [2] in which the mathematical secret is the factorisation into two huge prime numbers of an even larger number. In this work we consider the problem of three-colouring of graphs: an instance is a graph (nodes and edges attaching some of them to one another) and a proof of three-colourability assigns to each vertex one out of three possible colours in a way that any two vertices connected by an edge have different colours, see Fig. 1(a). Some graphs are three-colourable, some are not, and the general problem of deciding whether a graph is three-colourable has no known efficient solution. However, given a colouring it is extremely easy to efficiently check whether the end points of every edge are assigned different colours. For this reason, three-colourability is a problem in NP, the class of all problems that are efficiently verifiable given a solution. Moreover, it is also NP-complete because an instance of any problem in NP can be efficiently simulated by an instance of three-colourability, so that if this latter were in P, the class of all problems efficiently solvable, then we would have P = NP, an equality which has been the most famous challenge of theoretical computer science for the last half century and which remains unsolved. A zero-knowledge proof for three-colourability has been introduced in Ref. [3] by assuming the existence of one-way functions, that is, functions that can be efficiently computed but for which finding a preimage of a particular output cannot. The zero-knowledge proof guarantees that upon participation to such an interaction, a prover would convince a verifier of the validity of the statement when it is indeed valid (completeness), would not convince the verifier when it is invalid (soundness), while not allowing the latter to improve their ability to find a three-colouring (zero-knowledge), but this is under the assumption that one-way functions exist. It is widely believed that a zero-knowledge proof for any NP-complete problem such as three-colourability is not possible without this extra computational assumption. If not, this would lead to vast implications in the world of complexity [4]. However, this feature is generally undesirable as it significantly weakens the long-term security of such zero-knowledge protocols, which are used, e.g., in certain crypto-currencies [5]. This may have important consequences, as security would be fully compromised if the specific one-way function used in the protocol is (later) found to be efficiently invertible. This aspect is particularly relevant given recent advances on quantum computing [6, 7]. 

Remarkably, it is possible to devise zero-knowledge protocols without the need of any computational assumption. The key idea, as developed by Ben-Or, Goldwasser, Kilian and Wigderson [9], is to generalise the interactive proof model such that several provers are now trying to convince a verifier of the three-colourability of a graph in perfect zero-knowledge without the need of any further assumption. Intuitively, this approach reflects the strategy used by police investigators when interrogating suspects in separate rooms in order to discern the truth more easily: it is harder to collectively lie about the validity of a statement when interrogated separately. The key difference between the multi-prover scenario and the original definition of interactive proof rests in the possibility to prevent several provers from talking to each other, a single prover always being able to talk to themself. This naturally suggests the use of spatial separation to enforce the impossibility to communicate [10, 11], at least for some short period of time: assuming the principle of special relativity (nothing can signal faster than the speed of light) and sending queries to the different provers simultaneously, there is a short time window during which they are physically unable to signal between each other. So far, these ideas have been mainly of purely theoretical interest, as known protocols required extremely large information transfer between the provers and verifiers, which prohibited their implementation.

In this work, we report experimental realisations of relativistic zero-knowledge proofs for an NP-complete problem (three-colourability). Specifically we develop an efficient implementation of the protocol recently established in Ref. [12] for two separated verifier-prover pairs. In practice, key challenges involve the generation of adequate large three-colourable graphs, as well as an efficient management of the randomness shared between the provers, achieved via suitable error-correcting codes. We report on two experiments: first, using Global Positioning System (GPS) clocks to synchronise the two verifiers, we performed the protocol at a distance of 400 m; second, using a triggering fibre between the two verifiers, we conducted the same test at a shorter distance of 60 m. In both cases, the full running time was about one second. The first implementation shows that the protocol at large distances is rather effortless since the wide relativistic separation only demands a moderate speed on the provers’ side; the second one demonstrates a clear potential for serviceable applications. Importantly, the security is enforced by relativistic constraints, and does not rely on any computational hypothesis such as the existence of one-way functions. Note that the aforementioned NP-completeness guarantees that any application based on a problem in NP can be (polynomially) cast into an instance of our protocol. For example, if you trust the Advanced Encryption Standard (AES) as a secure cryptographic primitive, you can transform AES instances into three-colourable graphs. Our implementation achieves security against classically correlated provers and we discuss the prospects of extending the security to the general case of quantum-mechanically correlated provers below. 

Some popular beliefs about the economy are at odds with expert research; they check if a refutation text changes people’s beliefs about rent controls; with economics students, most people stick to their beliefs after reading the refutation text

Dispelling misconceptions about economics. Jordi Brandts et al. Journal of Economic Psychology, November 9 2021, 102461. https://doi.org/10.1016/j.joep.2021.102461

Highlights

• Some popular beliefs about the economy are at odds with expert research.

• We study if a refutation text changes people’s beliefs about rent controls.

• Both in the lab and field the text induces a belief change towards expert knowledge.

• In the field, with economics students, the text is more effective than teaching.

• Most people, however, stick to their beliefs after reading the refutation text.

Abstract: Some popular views about the workings of the economy are completely at odds with solid empirical evidence and congruent theoretical explanations and therefore can be qualified as misconceptions. Such beliefs lead to support for harmful policies. Cognitive biases may contribute to explaining why misconceptions persist even when scientific information is provided to people. We conduct two experimental studies to investigate, for the first time in economics, whether presenting information in a refutational way affects people’s beliefs about an important socio-economic issue on which expert consensus is very strong: the harmful effects of rent controls. In the laboratory (Study 1) both our refutational and non-refutational messages induce a belief change in the direction of expert knowledge. The refutational message, however, does not improve significantly on the non-refutational one. In the field (Study 2), where participants are college students receiving economic training, the refutational text improves, subject to some caveats, on standard instruction but not on the non-refutational message. The main overall implications of our results are that providing information moderately reduces the misconception, but does not eliminate it, and that the refutational approach does not work better than providing the same information in a non-refutational manner.

JEL A12 A2 D9 I2

Keywords: MisconceptionsCognitive biasRefutationExperimentEconomic communicationRent control

Guatemalan university students: Men held more traditional attitudes about gender and the family than did women on all measures; gender differences on all scales were mediated by cynicism and religiosity

Social Axioms Mediate Gender Differences in Gender Ideologies Among Guatemalan University Students. Sandra Elizabeth Luna-Sánchez et al. Journal of Cross-Cultural Psychology, November 5, 2021. https://doi.org/10.1177/00220221211049543

Abstract: Gender role ideologies are embedded in cultural values and assumptions about life. Women’s greater endorsement of egalitarian beliefs may stem from gender differences in world views as indexed by social axioms. The purpose of this study was to examine potential mediators of gender differences in gender ideologies among university students in Guatemala, a country where traditional views are prevalent. Participants, 2,134 university students from nine campuses in different regions of Guatemala (43% male, 85% emerging adults), completed a Social Axioms Scale, along with three culturally relevant measures of gender ideology: the Historic-Sociocultural Premises Scale (HSCP) and the Machismo Measure that taps both traditional machismo and caballerismo (gentlemanliness). Consistent with previous research in other countries, men held more traditional attitudes about gender and the family than did women on all measures. Gender differences on all scales were mediated by cynicism and religiosity. Fate control mediated the gender differences in traditional machismo and the HSCP. These findings suggest that Guatemalan women and men through socialization, cultural demands, and life experiences develop gender-specific ways of viewing the world, and their attitudes about gender roles are shaped by those worldviews. The achievement of gender equality, a U.N. sustainable development goal, may require attention to the underlying world views of women and men.

Keywords: social axioms, cultural world views, gender differences in gender ideologies, machismo, Guatemala

Negative Emotion Decision-Making Dynamics: Amygdala-Prefrontal Pathways show that, behaviorally, girls exhibit higher response caution & more effective evidence accumulation, boys show more impulsive response

Developmental Sex Differences in Negative Emotion Decision-Making Dynamics: Computational Evidence and Amygdala-Prefrontal Pathways. Jiahua Xu et al. Cerebral Cortex, bhab359, October 13 2021, https://doi.org/10.1093/cercor/bhab359

Abstract: Sex differences in human emotion and related decision-making behaviors are recognized, which can be traced back early in development. However, our understanding of their underlying neurodevelopmental mechanisms remains elusive. Using developmental functional magnetic resonance imaging and computational approach, we investigated developmental sex differences in latent decision-making dynamics during negative emotion processing and related neurocognitive pathways in 243 school-aged children and 78 young adults. Behaviorally, girls exhibit higher response caution and more effective evidence accumulation, whereas boys show more impulsive response to negative facial expression stimuli. These effects parallel sex differences in emotion-related brain maturity linking to evidence accumulation, along with age-related decrease in emotional response in the basolateral amygdala and medial prefrontal cortex (MPFC) in girls and an increase in the centromedial amygdala (CMA) in boys. Moreover, girls exhibit age-related decreases in BLA–MPFC coupling linked to evidence accumulation, but boys exhibit increases in CMA–insula coupling associated with response caution. Our findings highlight the neurocomputational accounts for developmental sex differences in emotion and emotion-related behaviors and provide important implications into the neurodevelopmental mechanisms of sex differences in latent emotional decision-making dynamics. This informs the emergence of sex differences in typical and atypical neurodevelopment of children’s emotion and related functions.

Keywords: children, development, emotion, sex dimorphism, task fMRI

It was women, not men, who were more likely to report being aroused by aggression, mostly consensual; & were also more likely to report actively seeking for aggression and wanting to see more aggression in mainstream pornography

Who Seeks Aggression in Pornography? Findings from Interviews with Viewers. Eran Shor. Archives of Sexual Behavior, Nov 8 2021. https://link.springer.com/article/10.1007/s10508-021-02053-1

Abstract: Despite the recent proliferation of research on aggression in pornography, we still know relatively little about the preferences and perceptions of viewers themselves. In particular, very little research has examined how women who watch pornography feel when encountering aggression toward women. To explore this question, we conducted interviews with 122 regular pornography viewers (61 women, 60 men, and 1 gender-diverse). Quantitative and qualitative analyses of the data show that the majority of both men and women reported that they did not enjoy aggressive content. However, in contrast to common conceptions among most scholars and pundits, it was women, not men, who were more likely to report being aroused by aggression, mainly consensual aggression toward women, which was perceived as pleasurable. Women were also more likely to report actively seeking for aggression and wanting to see more aggression in mainstream pornography. These findings challenge long-held radical feminist views regarding the preferences of both women and men and offer new insights on the relationship between gender and sexual fantasies.

Interviewees from Bangladesh, Belgium, Brazil, Canada, China, Costa Rica, France, India, Indonesia, Iran, Japan, Korea, Lebanon, Mauritius, Mexico, Pakistan, Peru, Romania, Russia, Singapore, Slovenia, Sri Lanka, Syria, the United Kingdom, the United States, Venezuela, Vietnam, and Zimbabwe.

Like-minded political discussion are rare, and the readiness to engage in them is more strongly determined by personality than by ideology or the means of communication

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.

People told the most lies per social interaction over synchronous, distributed, and recordless media (the phone, video chat),; lying rates were also associated with aversive personality traits, plus antisocial, and relational deception motives

Revisiting the Relationship Between Deception and Design: A Replication and Extension of Hancock et al. David M Markowitz. Human Communication Research, hqab019, November 8 2021. https://doi.org/10.1093/hcr/hqab019

Abstract: Evidence published nearly 20 years ago suggested people tell more lies per social interaction via synchronous, distributed, and recordless media (the phone) versus relatively richer (face-to-face communication) and leaner media (email, instant messaging). With nontrivial changes to the size and variety of our media landscape, it is worth re-examining the relationship between deception and technology. Over 7 days, 250 participants reported their social interactions and lies across face-to-face communication, social media, texting, the phone, video chat, and email. Replicating Hancock, Thom-Santelli, and Ritchie (2004), people told the most lies per social interaction over synchronous, distributed, and recordless media (the phone, video chat), though the effects were small and between-person effects explained more variance than between-media effects. Lying rates were also associated with aversive personality traits, plus antisocial, and relational deception motives. Together, while media options have evolved, technological design features often remain stable and indicate deception rates. Theoretical contributions are discussed.

Wrongful convictions' awards: Average is $6.1 million ($1334/day of incarceration); initial incarceration is valued at over $50,000 for the first day; year one is valued at $1.5 million ($4000/day); marginal cost of the 10th year is $350,000 ($950/day)

Pain, suffering, and jury awards: A study of the cost of wrongful convictions. Mark A. Cohen. Criminology & Public Policy, November 8 2021. https://doi.org/10.1111/1745-9133.12559

Research summary: This paper estimates the cost of wrongful convictions based on analysis of jury awards and settlements for individuals who were wrongfully convicted and incarcerated for crimes they did not commit. Key variables of interest are number of days spent in prison, days on probation, and demographics of wrongfully convicted and their families. The average “cost” of a wrongful conviction is estimated to be $6.1 million, or $1334 per day of incarceration, while the marginal cost decreases over time: initial incarceration is valued at over $50,000 for the first day; year one is valued at $1.5 million ($4000/day), while the marginal cost of the 10th year is estimated to be approximately $350,000 ($950/day).

Policy implications: State mandated compensation for wrongfully convicted individuals who oftentimes spend years in prison for crimes they did not commit is highly variable and in many cases bears little relationship to either the monetary or nonmonetary harms endured. In addition to providing benchmarks for more appropriate compensation, these estimates provide a foundation for future benefit-cost analyses of policies that might reduce wrongful convictions such as increased expenditures for DNA testing or indigent defense counsel.