Wednesday, August 7, 2019

Recreational marijuana laws reduce annual opioid mortality in the range of 20%–35%, with particularly pronounced effects for synthetic opioids

The Effects of Recreational Marijuana Legalization and Dispensing on Opioid Mortality. Nathan W. Chan, Jesse Burkhardt, Matthew Flyr. Economic Enquiry, August 6 2019. https://doi.org/10.1111/ecin.12819

Abstract: This study documents how the changing legal status of marijuana has impacted mortality in the United States over the past two decades. We use a difference‐in‐difference approach to estimate the effect of medical marijuana laws (MML) and recreational marijuana laws (RML) on fatalities from opioid overdoses, and we find that marijuana access induces sharp reductions in opioid mortality rates. Our research corroborates prior findings on MMLs and offers the first causal estimates of RML impacts on opioid mortality to date, the latter of which is particularly important given that RMLs are far more expansive in scope and reach than MMLs. In our preferred econometric specification, we estimate that RMLs reduce annual opioid mortality in the range of 20%–35%, with particularly pronounced effects for synthetic opioids. In further analysis, we demonstrate how RML impacts vary among demographic groups, shedding light on the distributional consequences of these laws. Our findings are especially important and timely given the scale of the opioid crisis in the United States and simultaneously evolving attitudes and regulations on marijuana use. (JEL I18, K32, H75)

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Why "the scale of the opioid crisis in the" US? Why are you working in this area and know not of other places with similar issues? Less passion and more data, it is happening also in parts of the UK (https://www.nytimes.com/2019/08/07/world/europe/scotland-heroin-deaths.html).

Though we are not yet capable of fully determining who conspiracy theorists are, conspiratorial thinking, paranormal beliefs, & political orientations are good predictors of conspiracy beliefs

Who Are Conspiracy Theorists? A Comprehensive Approach to Explaining Conspiracy Beliefs. Adam M. Enders, Steven M. Smallpage. Social Science Quarterly, August 6 2019. https://doi.org/10.1111/ssqu.12711

Abstract
Objective: This study disentangles the known correlates of conspiracy beliefs—such as the general predisposition toward conspiratorial thinking, authoritarianism, and partisan and ideological predispositions—in order to better understand the psychological antecedents of such beliefs and answer the question: Who are conspiracy theorists?

Methods: We use classification and regression tree models to explain individual beliefs in specific conspiracy theories, employing a large set of known correlates of conspiratorial thinking.

Results: Depending on the characteristics of the conspiracy theory employed on the survey, we find that political orientations and conspiratorial thinking provide the most analytical leverage in predicting individual conspiracy beliefs. Furthermore, paranormal beliefs were more predictive than previous literature suggests, while psychological biases demonstrated very limited predictive utility.

Conclusions: The psychological antecedents of conspiracy beliefs used to explain those beliefs vary considerably by the stimuli or events at the center of a given conspiracy theory. Therefore, disproportionately favoring one type of conspiracy theory on one's survey may result in inferences about conspiracy theorists that do not translate across studies. Furthermore, though we are not yet capable of fully determining who conspiracy theorists are, conspiratorial thinking, paranormal beliefs, and political orientations are more predictive of particular conspiracy beliefs than other attitudes, predispositions, and orientations.

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A great deal of recent research has demonstrated that conspiracy beliefs are a central component of modern culture and politics (e.g., Brotherton, 2015; Oliver and Wood, 2014; Uscinski and Parent, 2014), rather than indicators of radical alienation or psychopathology. More commonplace than once thought, belief in conspiracy theories can have negative effects on individuals and democratic society. For example, mere exposure to conspiracy theories has been found to reduce individual intention to vote and make political donations (Butler, Koopman, and Zimbardo, 1995), participate in politics more generally (Jolley and Douglas, 2014), and place trust in government services and institutions (Einstein and Glick, 2015). Thus, understanding conspiracy theories and those who believe them has positive implications not only for “conspiracy theorists,” but also for those around them, as well as normative implications for theories of culture and government. The rapidly expanding, albeit nascent, literature on conspiracy theories has identified a substantial set of attitudes, predispositions, orientations, and psychological mechanisms that are related to conspiracy beliefs. One characteristic shared by many of these studies is a focus on one, or a small subset of, correlate(s) of conspiracy beliefs. It is perfectly reasonable and expected that a young literature may move forward in such a piecemeal fashion as researchers strive to build a theoretical foundation for the subfield. However, such an erratic procession is not without consequential limitations. While we have learned a great deal about the correlates of conspiracy beliefs in a vacuum, we have little empirical foundation for understanding how those correlate work together. Indeed, we have only a tenuous grasp of who conspiracy theorists are.
In this article, we offer information about which factors related to conspiracy beliefs provide the most analytical leverage in correctly predicting individual conspiracy beliefs. Such information is useful for both identifying the relevant characteristics of conspiracy theorists more precisely, and in further developing our theories about the psychological antecedents of specific conspiracy beliefs (Wood, 2017). Ultimately, a firmer understanding of the characteristics of conspiracy theorists can help us understand what about the conspiratorial frame of mind gives rise to the negative effects of conspiracism, and possibly help combat such effects.
To be more specific, this study offers three important developments of recent work on the correlates of conspiracy beliefs. First, we decipher which correlates seem to analytically matter most when a substantial set of previously identified factors are accounted for. In doing this, we find that the most predictive correlates of nine specific and commonly employed conspiracy beliefs are conspiratorial thinking, political orientations, and paranormal beliefs, while measures of several psychological biases and sociodemographic characteristics offer little utility in correctly classifying conspiracy beliefs. Second, we identify the characteristics of specific conspiracy theories that seem to affect which correlates are most predictive of related beliefs. More specifically, we find that the previously identified correlates differentially affect different “types” of conspiracy theories—namely, those with and without partisan political content. Finally, we discuss our general ability to answer the question “who are conspiracy theorists?” and provide practical recommendations for scholars interested in explaining conspiracy theories and those who believe them.
Background
A conspiracy theory is a “proposed explanation of events that cites as a main causal factor a small group of persons (the conspirators) acting in secret for their own benefit, against the common good” (Uscinski, Klofstad, and Atkinson, 2016:2). A conspiracy belief, then, is a belief in a specific conspiracy theory. Perhaps the most obvious theoretical cause of specific conspiracy beliefs is “conspiratorial thinking,” a psychological state that is the amalgamation of “stable individual differences in the general tendency to engage with conspiracist explanations for events” (Brotherton, French, and Pickering, 2013:1). Conspiratorial thinking is a general tendency to view the world a certain way (Brotherton, 2015) rather than any specific trait, predisposition, or set of attitudes. A great deal of recent work on conspiratorial thinking has turned its attention away from specific conspiracy beliefs and toward the goal of identifying this mindset in individuals (e.g., Imhoff and Bruder, 2014; Lantian et al., 2016; Uscinski and Parent, 2014; Wood, 2017). Most of the unique measurement strategies utilized to identify conspiracy theorists ask survey respondents to what extent they agree with claims such as “I think that events which superficially seem to lack a connection are often the result of secret activities” (Bruder et al., 2013), or “Much of our lives are being controlled by plots hatched in secret places” (Uscinski and Parent, 2014).
Conceptually related to conspiratorial thinking are specific psychological biases that may cause—individually or cumulatively—one to view the world through the lens of conspiracism. Patternicity, the predisposition to delineate patterns from what are truly random events, is an obvious hallmark of conspiratorial thinking (Brotherton, 2015). Those individuals who are particularly susceptible to patternicity are more likely to “see” the connections between disparate events. Brotherton and French (2014, 2015) have also identified susceptibility to the conjunction fallacy and intentionality bias as characteristics of individuals with conspiracy beliefs. Indeed, conspiracy theorists are likely to believe in several conspiracy theories that are logically at odds with each other and ascribe intention to perceived actions that are truly accidental or coincidental in nature.
Political scientists focusing on the role of political identities and orientations have found that partisanship and ideological self‐identifications are significantly related to many American conspiracy theories. For instance, Hartman and Newmark (2012) and Pasek et al. (2015) identify partisanship as a key predictor of conspiracy beliefs about the birthplace of Barack Obama. Miller, Saunders, and Farhart (2016) find that left–right political orientations serve as the latent structure that underlies a host of American beliefs in conspiracy theories about climate change, the birthplace of Barack Obama, the 9/11 terror attacks, and electoral fraud. The effects of partisan and ideological orientations also appear to translate in nature, though not exact character, across political context. van Prooijen, Andre, and Pollet (2015) find politically extreme individuals—those who reside on the edges of scales of ideological orientations, regardless of political context—tend to be more conspiratorial than their moderate counterparts.
A host of other individual differences have also been identified as correlates of conspiracy beliefs. Authoritarianism, for example, has long been a fixture in the literature on conspiracy beliefs (Abalakina‐Paap et al., 1999; McHoskey, 1995). Since authoritarian individuals are more likely to blame others for their problems, they are also more likely to believe in conspiracy theories that tend to posit that some unknown force is guiding events. More recent work has also identified paranormal thinking—the tendency to believe in the role of supernatural forces in everyday life, and individuals' ability to engage such forces—as an important correlate of conspiracy beliefs (Darwin, Neave, and Homes, 2011; Oliver and Wood, 2014). Lastly, personality characteristics (Swami, Chamorro‐Premuzic, and Furnham, 2010), anomia (Goertzel, 1994), and self‐uncertainty and belongingness (van Prooijen, 2016) have been found to correlate with conspiratorial thinking.
Finally, some have asserted the role of nonpsychological characteristics, such as age, race, gender, socioeconomic status, and educational attainment, in promoting conspiratorial thinking. Much of this work comes from a more historical, sociological tradition that emphasized “fringe” status in society as a major cause of conspiratorial worldview (e.g., Hofstadter, 1964). Although we are more interested in the psychological correlates of conspiracy beliefs, we nevertheless consider whether sociodemographic characteristics affect conspiratorial thinking in addition to other psychological variables.
We do not purport to have included every known correlate of conspiracy beliefs in the above lists, but we do believe that our review of the literature conveys the simple point that there are a great many of such correlates. And, even though none of the correlates of conspiracy beliefs we have outlined above strikes us as unreasonable or improbable, we are left wondering which of these correlates actually matters for classifying conspiracy beliefs. Very little of the research outlined above considers simultaneously the effects of several of the identified constructs on conspiracy beliefs. Gaining some grasp on this question is important for two reasons. First, it will help us better understand which predispositions, orientations, and attitudes best characterize conspiracy theorists. An understanding of the characteristics of conspiracy theorists will aid us in deciphering the best candidates for causal first‐movers of conspiracy beliefs. This has implications for our theories of the psychological antecedents of conspiracy beliefs, and the measurement strategies we employ to capture and explain such beliefs. Second, this work will help us more fully answer perhaps the most illusive question faced by the literature: Who are conspiracy theorists?

Does Exposure to Gender Role Models Increase Women’s Political Ambition? It seems not.

Does Exposure to Gender Role Models Increase Women’s Political Ambition? A Field Experiment with Politicians. Florian Foos and Fabrizio Gilardi. Journal of Experimental Political Science, August 7 2019. https://doi.org/10.1017/XPS.2019.21

Abstract: There is a persistent gender gap in motivations to run for political office. While exposure to role models is widely believed to increase women’s political ambition, there is little field experimental evidence on whether exposure to female politicians in realistic settings can increase political ambition. We conducted a field experiment in which a sample of 612 female students was randomly assigned to receive emails inviting them to an event that included career workshops with female politicians, or no email. The treatment increased interest in the ongoing national election campaign, but, against expectations, did not have any positive effect on political ambition. Our results suggest that female politicians who discuss their experience bluntly, instead of following a motivational script, may fail to motivate other women to pursue a political career. These results highlight the need for more research into the type of events and messages that bring more women into politics.

We identify evolutionary advantages that may incentivize tolerance toward extra‐group individuals in humans & nonhuman primates, including enhanced benefits in the domains of transfer, mating, & food acquisition


The evolution of intergroup tolerance in nonhuman primates and humans. Anne C. Pisor, Martin Surbeck. Evolutionary Anthropology: Issues, News, and Reviews, August 6 2019. https://doi.org/10.1002/evan.21793

Abstract: Primate individuals use a variety of strategies in intergroup encounters, from aggression to tolerance; however, recent focus on the evolution of either warfare or peace has come at the cost of characterizing this variability. We identify evolutionary advantages that may incentivize tolerance toward extra‐group individuals in humans and nonhuman primates, including enhanced benefits in the domains of transfer, mating, and food acquisition. We highlight the role these factors play in the flexibility of gorilla, chimpanzee, bonobo, and human behavior. Given humans have an especially broad range of intergroup behavior, we explore how the human foraging ecology, especially large spatial and temporal fluctuations in resource availability, may have selected for a greater reliance on tolerant between‐community relationships—relationships reinforced by status acquisition and cultural institutions. We conclude by urging careful, theoretically motivated study of behavioral flexibility in intergroup encounters in humans and the nonhuman great apes.

1 INTRODUCTION

Attempting to explain the prevalence of intergroup aggression in primates, especially in humans (Homo sapiens sapiens), evolutionary anthropologists have focused extensively on intergroup contest and warfare. In response, other evolutionary anthropologists have focused extensively on peace systems in primates, especially in humans. Focusing on these two ends of the spectrum—war or peacefulness—has come at the cost of fully characterizing within‐species variation in individuals' behavioral strategies in intergroup encounters (e.g., Refs. 1-4; see also, Ref. 5: table 22‐1). Furthermore, both of these approaches emphasize selection pressures that favor or disfavor intergroup aggression; less researched are the selection pressures that, given disincentives for intergroup aggression, favor tolerant encounters and the prolongment of tolerant encounters in intergroup association.

In the present review, our goal is to call for explicit theorization about the individual‐level selection pressures that favored flexible behavior in intergroup encounters in humans and nonhuman primates, especially the often‐overlooked pressures that may favor tolerant encounters and association given disincentives for aggression. We review how tolerant behavior toward extra‐group conspecifics in specific domains—such as food access, mating, and reconnaissance before transfer—may have been favored by natural selection in nonhuman primates. In the course of this review, we pay special attention to the group‐living, nonhuman great apes, but not because these species are necessarily the best analogies for intergroup behavior in humans. We focus on these species for two reasons: first, due to our common ancestry, humans and the extant nonhuman great apes share a number of traits derived within the Primate order, suggesting that there is (at least some) insight to be gained by drawing comparisons between these species; and second, to highlight how little we still know about intergroup encounters in the nonhuman great apes, especially in gorillas and bonobos.

Given what has been observed of intergroup behavior in nonhuman primates, we assess whether consideration of the potential selective benefits favoring intergroup encounter and association in these species provides insight into human behavior. Our review of the literature suggests that the particularly high prevalence of intergroup tolerant encounter and association in humans may be derived, even within the great apes; we hypothesize that this high prevalence reflects human reliance on resources that vary extensively in their availability across space and time. Given that our field has invested much energy into studying the selection pressures favoring or disfavoring intergroup aggression, we conclude by urging evolutionary anthropologists to explicitly theorize about individual‐level selection pressures that may favor intergroup tolerant encounters, and even prolonged intergroup association, so that we can better understand the variation in intergroup behavior within and between species.


4 DISCUSSION

In evolutionary anthropology and in disciplines influenced by it, a common current assumption made by researchers is a “strong human universal toward parochial altruism”—in‐group favoritism at out‐group cost.86 Research focus on chimpanzees as a referential model for human behavior34 tends to promote this perspective. However, evidence suggests that individual behavior in intergroup encounters is actually quite flexible, both in humans (e.g., per the study from which the preceding quote was drawn86) and in the group‐living great apes generally. Disincentives for intergroup aggression have been thoroughly discussed by other reviews; however, these disincentives provide insight only into when selection could favor individual tolerance toward extra‐group members, but not why it does under these circumstances. Here, drawing on existing observations of nonhuman primates, we assembled potential fitness benefits that may favor intergroup tolerant encounter and association (Table 1). Though scientists know comparatively little about intergroup encounters in bonobos and gorillas relative to chimpanzees—a situation that should be remedied—the fitness benefits we identified seem to account for at least some of the observed variability in intergroup behavior in bonobos and gorillas.

Our review of the literature suggests that the benefits favoring intergroup tolerant encounter and association in nonhuman primates can account for some, but not all, of the flexibility of intergroup tolerance in humans. In both humans and nonhuman primates, mating and transfer, as facilitated by visitation, and opportunities for social learning are potential benefits to be gained from intergroup tolerant encounter and association. Likewise, across the Primate order, kinship and partner preferences can further amplify the benefits and minimize the costs of encounter. However, humans have a much higher prevalence of intergroup tolerant encounter and association than do nonhuman primates—at least, as observed to date. Evidence from anthropology and across the social sciences suggests that humans' reliance on resources with extensive spatial and temporal variability has necessitated flexible interest in between‐community relationships as a means of managing the risks of resource shortfalls and ensuring access to nonlocally available resources. When and where the benefits of between‐community resource access have been high, cultural institutions and social status have also enhanced and reinforced these benefits. This is not to say that humans do not engage in intergroup aggression—the ethnographic, archaeological, and contemporary records provide ample evidence of parochialism and warfare—but rather that human intergroup behavior can be both more tolerant and more aggressive than what we have observed in our closest relatives and that this flexibility in intergroup behavior is functional.

We advance the hypotheses outlined in this review for testing by the evolutionary anthropological community. Similar ideas with respect to the importance of between‐community resource access have been outlined by functionalist anthropologists, archaeologists, and human behavioral ecologists previously—although usually without treatment of why between‐community resource access is of particular importance in humans. We hope that by amalgamating these perspectives and building upon them, the present paper inspires newfound interest in the flexibility of human and nonhuman great ape intergroup behavior, moving our discipline beyond its current focus on parochialism. In addition to our larger hypothesis with respect to the human foraging ecology, we wish to highlight other related questions to be addressed by future work. (1) The higher the frequency of shortfalls, the more likely that individuals will recall these shortfalls (whether via their own memories or even via oral traditions) and maintain between‐community relationships accordingly50, 51—but how frequent must they be? Is once every several generations enough? (2) Will the connections we drew between status acquisition, cultural institutions, and the relative importance of between‐community resource access be supported by additional data? To date, the connection between status and between‐community relationships has been more theoretical than empirical. (3) Which poses stronger selection pressure in humans: benefits gained via intergroup tolerant encounters and association in the currency of between‐community resource access, or the cost of mortality risk from aggression and warfare,37 potentially reduced by intergroup tolerant encounters and association?

To answer the above questions and improve the accuracy of our characterizations of sociality in both humans and nonhuman great apes, researchers will need to collect targeted data assessing the predictors of intergroup behavior. For field researchers studying humans, we urge caution with respect to reliance on observational data and “complete” social networks. Asking participants about their social strategies for mitigating shortfalls,49 their preferences for same‐community vs between‐community relationships,41, 42 and their extra‐community ties85 may provide a more accurate picture of the flexibility of human sociality. Furthermore, the dedication of increased research effort to intergroup encounters and association in gorillas and bonobos, as well as habituation of neighboring groups, will improve our understanding of sociality in the group‐living nonhuman great apes.

In the present review, we opted not to unpack the nature of human “groups” nor human group psychology. Humans are adept at cognizing groups of various kinds—from groups formed in experimental contexts to interest‐based groups to ethnic or religious groups—and at recognizing their boundaries. A number of the papers and book chapters we reviewed here discuss potential derived functions of group living in humans (see Refs. 53, 54, 56, 69). Our larger point is that human reliance on resources that vary in their spatial and temporal availability often necessitates relationships spanning distance; in general, the group‐living great apes evidence flexible interest in intergroup encounters and association (Box 1), and it is likely that this flexible interest became even more important in the human lineage (Section 3.2). While relationships spanning distance sometimes span ethnolinguistic boundaries, for example, or religious boundaries, they do not necessarily. As such, questions of the proliferation of different types of human groups, and how ethnic groups may have been built on the scaffolding of social relationships through which nonlocal resources could be accessed (e.g.,83), we leave to other papers.

Given the lack of attention the benefits of intergroup tolerant encounter and association have received in evolutionary anthropology, the present review reflects initial theorizing about these incentives; as such, we have not explored the roles of constraints, including phylogeny and life history constraints, nor the affordances of a comparative approach with non‐primate species. Phylogeny and life history constraints likely affect the prevalence and flexibility of intergroup tolerance in different species of primates. For example, the relationship between intergroup tolerance and the ecological and social factors discussed here may partially reflect a third variable, phylogenetic signal. Whether such constraints explain existing observational data is a question to be answered by future work. Furthermore, we chose not to pursue a comparative approach with non‐primate species. Though the high incentives for intergroup tolerant encounter and association observed in humans may have better analogies among non‐primate vertebrates or even insects,2 our goal here was to explore intergroup tolerance in humans in the context of nonhuman primates rather than to find the closest‐match analogy for human behavior.

5 CONCLUSION
Intergroup behavior in primates is flexible, and the prevalence of intergroup tolerant encounters and association varies across species. To be sure, incentives for aggression vary, as discussed extensively in existing work; however, when incentives for aggression are low or absent, why would natural selection favor tolerant behavior toward extra‐group members—or even increased rates of intergroup tolerant encounter and association? Drawing inferences from the existing primatological literature, we highlighted benefits favoring intergroup tolerant encounter and association in the Primate order, including in group‐living nonhuman apes and humans, such as transfer, mating, and food acquisition. Humans are unique among primates in our high prevalence of intergroup tolerance, however, and data from across the social sciences suggest the relevance of the human foraging ecology—especially the spatial and temporal availability of resources on which we depend—in explaining the human pattern. Future research should work to better document the variability in intergroup behavior in the group‐living apes, especially in gorillas, bonobos, and humans, using methods of data collection designed specifically for this endeavor.

Childhood intelligence, much more than adult personality, is a predictor of saving 40 years later; how intelligence affected education and also occupation explains adult financial success

Factors influencing adult savings and investment: Findings from a nationally representative sample. Adrian Furnham, Helen Cheng. Personality and Individual Differences, Volume 151, 1 December 2019, 109510. https://doi.org/10.1016/j.paid.2019.109510

Abstract: This study explored a longitudinal data set of over 5766 adults examining factors that influence adult savings and investment. Data were collected at birth, in childhood (at age 11) and adulthood (at ages 33 and 50 yrs) to examine the effects of family social status, childhood intelligence, adult personality traits, education and occupation, and personal financial assessment on adult savings and investment. Results from structural equation modelling showed that parental social status, educational qualifications and occupational prestige, trait Conscientiousness, personal financial assessment and gender all had significant and direct effects on adult savings and investment, accounting for 26% of the total variance. The strongest predictor of adult savings and investment was their personal subjective financial assessment followed by educational qualifications and current occupational prestige. Limitations and implications are considered.

Political skill and outcomes in social life: Political skill was related to self-rated social life quality, perceiver-rated likeability, and friend-rated positive sociality

Political skill and outcomes in social life. Michael Z. Wang, Judith A. Hall. Personality and Individual Differences, Volume 149, 15 October 2019, Pages 192-199. https://doi.org/10.1016/j.paid.2019.05.010

Abstract: The concept of political skill has been extensively studied in work and professional life but not yet in social life. To study how political skill relates to social life outcomes, participants engaged in a videotaped interaction in the laboratory that was rated for likeability and intelligence by naïve perceivers and coded for behavior by trained coders. Participants also took the Political Skill Scale (PSI; Ferris et al., 2005) (with workplace references removed) and other personality questionnaires. Finally, ratings from participants' friends were gathered. Political skill was related to self-rated social life quality, perceiver-rated likeability, and friend-rated positive sociality. When controlling for extraversion, self-monitoring, and social self-efficacy, all relations stayed significant except ones with self-rated social life quality. Results were strongest for the PSI's subscales for networking ability and interpersonal influence. Sounding confident and initiating topics mediated relations between political skill and perceiver ratings.

Tuesday, August 6, 2019

Efforts to improve therapy models' general quality do not appear to have translated into improved outcomes; our results suggest that even with a therapy of perfect quality, achieved effect sizes may be modest

An Upper Limit to Youth Psychotherapy Benefit? A Meta-Analytic Copula Approach to Psychotherapy Outcomes. Payton J. Jones et al. Clinical Psychological Science, August 6, 2019. https://doi.org/10.1177/2167702619858424

Abstract: Across 50 years of research, extensive efforts have been made to improve the effectiveness of psychotherapies for children and adolescents. Yet recent evidence shows no significant improvement in youth psychotherapy outcomes. In other words, efforts to improve the general quality of therapy models do not appear to have translated directly into improved outcomes. We used multilevel meta-analytic data from 502 randomized controlled trials to generate a bivariate copula model predicting effect size as therapy quality approaches infinity. Our results suggest that even with a therapy of perfect quality, achieved effect sizes may be modest. If therapy quality and therapy outcome share a correlation of .20 (a somewhat optimistic assumption given the evidence we review), a therapy of perfect quality would produce an effect size of Hedges’s g = 0.83. We suggest that youth psychotherapy researchers complement their efforts to improve psychotherapy quality by investigating additional strategies for improving outcomes.

Keywords: meta-analysis, psychotherapy, youth psychotherapy, psychotherapy research, copula, open data, open materials

The present paper aims to question the very possibility, or at least the theoretical significance, of teasing apart mental and bodily acts

What is ‘mental action’? Yair Levy. Philosophical Psychology , Volume 32, 2019 - Issue 6, Pages 969-991. Jul 3 2019. https://doi.org/10.1080/09515089.2019.1632427

ABSTRACT: There has been a resurgence of interest lately within the philosophy of mind and action in the category of mental action. Against this background, the present paper aims to question the very possibility, or at least the theoretical significance, of teasing apart mental and bodily acts. After raising some doubts over the viability of various possible ways of drawing the mental-act–bodily-act distinction, the paper draws some lessons from debates over embodied cognition which, arguably, further undermine the credibility of the distinction. The insignificance of the distinction is demonstrated in part by showing how the focus on “inner” acts hampers fruitful discussion of Galen Strawson’s skepticism of mental agency. Finally, the possibility is discussed that a distinction between covert and overt action should supplant the one between mental and bodily action.

KEYWORDS: Mental action, embodied cognition, extended mind, covert action, overt action

Partisan extremity was related to lower levels of cognitive flexibility, regardless of political orientation, across 3 independent cognitive assessments of cognitive flexibility

Zmigrod, L., Rentfrow, P. J., & Robbins, T. W. (2019). The partisan mind: Is extreme political partisanship related to cognitive inflexibility? Journal of Experimental Psychology: General, http://dx.doi.org/10.1037/xge0000661

Abstract: The rise of partisan animosity, ideological polarization, and political dogmatism has reignited important questions about the relationship between psychological rigidity and political partisanship. Two competing hypotheses have been proposed: 1 hypothesis argues that mental rigidity is related to a conservative political orientation, and the other suggests that it reflects partisan extremity across the political spectrum. In a sample of over 700 U.S. citizens, partisan extremity was related to lower levels of cognitive flexibility, regardless of political orientation, across 3 independent cognitive assessments of cognitive flexibility. This was evident across multiple statistical analyses, including quadratic regressions, Bayes factor analysis, and interrupted regressions. These findings suggest that the rigidity with which individuals process and respond to nonpolitical information may be related to the extremity of their partisan identities.

In experiments with university students and low‐educated adults all participants decreased in confidence after seeing any peer work in numerical topics

Poor peer work does not boost student confidence. Heather Barry Kappes, Barbara Fasolo,  Wenjie Han, Jessica Barnes, Janna Ter Meer. Journal of Behaviroal Decision Making, August 6 2019. https://doi.org/10.1002/bdm.2148

Abstract: Students' low confidence, particularly in numerical topics, is thought to be a barrier to keeping them engaged with education. We studied the effects on confidence of exposure to a peer's work of varying quality (very good or bad) and neatness (messy or neat). Previous research underpinned our hypothesis that a peer's bad‐quality work—which students rarely see—might boost student confidence more than very good work. We also predicted that a peer's very good work—which students are often shown—might be less discouraging if it were messy, suggesting it required effort and struggle. However, in experiments with university students and low‐educated adults, these hypotheses were not supported, and all participants decreased in confidence after seeing any peer work. The failure to find support for these hypotheses can inform future research into social comparison effects on self‐confidence in numerical topics. These results also have practical implications for teachers and managers who are expected to provide examples of peer work.


Desire is commonly understood as a mental state in relation to which we are passive; seems to arise in us spontaneously, without antecedent deliberation; seems a type of mental state which is not up to us

Active desire. Uku Tooming. Philosophical Psychology, Volume 32, 2019 - Issue 6, Pages 945-968, Jun 15 2019. https://doi.org/10.1080/09515089.2019.1629406

ABSTRACT: Desire is commonly understood as a mental state in relation to which we are passive. Since it seems to arise in us spontaneously, without antecedent deliberation, it also seems to constitute a paradigmatic type of mental state which is not up to us. In this paper, I will contest this idea. I will defend a view according to which we can actively shape our desires by controlling the way in which we imagine their contents. This view is supported both by behavioral and neural data which indicate that imagining can either strengthen or weaken our existing desires. Arguably, this influence is made possible by our capacity to imaginatively elaborate on the content of our desires. This gives a reason to think that what we desire is partially under our control. It is under our control only partially because we can influence our desires insofar as their content appears appealing to us in imagination.

KEYWORDS: Desire, agency, imagination, affect, reasons


Negative association of self-reported stress and number of SMS, as well as a positive relation of stress and call duration; mood was linked negatively with total usage time & call duration

Insights: Future Implications of Passive Smartphone Sensing in the Therapeutic Context. E.-M. Messner et al. Verhaltenstherapie 2019, https://doi.org/10.1159/000501735

Abstract
Background: Due to the ubiquitous use of smartphones in daily life, they offer unique opportunities to study human behaviour. This study sheds light on associations between self-reported stress, drive and mood levels and smartphone usage behaviour.
Methods: A total of 157 students installed the Insights app on their personal smartphone and tracked smartphone usage behaviour. Furthermore, students assessed self-reported levels of stress, drive and mood for 8 weeks.
Results: Three multi-level models were used to associate smartphone usage behaviour and self-reported mood, drive and stress levels. Results indicate a negative association of self-reported stress and number of SMS (–3.539, SE = 0.937) as well as a positive relation of stress and call duration (0.018, SE = 0.937). Mood was linked negatively with total usage time (–0.019, SE = 0.004) and call duration (–0.016, SE = 0.007). Moreover, drive was negatively associated with Facebook usage time (–0.127, SE = 0.041).
Discussion: Overall smartphone usage behaviour is negatively associated with measurements of well-being.
Conclusion: Passive smartphone tracking could assist in the standardized assessment of behavioural data in real life in the future. Due to the risk of data misuse, ethical, legal and clinical guidelines have to be developed.

Keywords: Drive · Smartphone-tracking · Psychotherapy · Mood · Stress ·


In philosophy of mind, the difference between perception & misperception is seen in terms of accuracy (perception is accurate while misperception is inaccurate); but perceptual experience actually involves widespread inaccuracy

Perceptual precision. Adrienne Prettyman. Philosophical Psychology, Volume 32, 2019 - Issue 6, Pages 923-944. https://doi.org/10.1080/09515089.2019.1598765

ABSTRACT: The standard view in philosophy of mind is that the way to understand the difference between perception and misperception is in terms of accuracy. On this view, perception is accurate while misperception is inaccurate. However, there is some evidence (albeit controversial evidence) that perceptual experience actually involves widespread inaccuracy. I add to that evidence in the paper. Then I point toward a way of understanding the difference between perception and misperception, not in terms of accuracy alone, but in terms of precision. That is, I argue that perceptual experience is designed to enable more fine-grained discrimination among the properties that are most useful for action, even if that involves inaccuracy. The view in this paper motivates a new account of illusion, on which illusions are imprecise as well as inaccurate. I call this the Precision Account of Illusion.

KEYWORDS: Perception, illusion, psychology, philosophy of mind


An empirical investigation of guilty pleasure (trash TV, kitsch)

An empirical investigation of guilty pleasures. Kris Goffin & Florian Cova. Philosophical Psychology, Aug 5 2019. https://doi.org/10.1080/09515089.2019.1646897

ABSTRACT: In everyday language, the expression ‘guilty pleasure’ refers to instances where one feels bad about enjoying a particular artwork. Thus, one’s experience of guilty pleasure seems to involve the feeling that one should not enjoy this particular artwork and, by implication, the belief that there are norms according to which some aesthetic responses are more appropriate than others. One natural assumption would be that these norms are first and foremost aesthetic norms. However, this suggestion runs directly against recent findings in experimental philosophy, according to which most people deny the existence of aesthetic norms. Through three studies, we investigated people’s experiences of guilty pleasures and the norms that underlay these experiences. We tentatively conclude that guilty pleasures are more often connected to one’s personal norms and social expectations than to properly aesthetic norms.

KEYWORDS: Experimental philosophy, aesthetic normativity, emotions, guilty pleasures

Psychological reactions to human versus robotic job replacement

Psychological reactions to human versus robotic job replacement. Armin Granulo, Christoph Fuchs & Stefano Puntoni. Nature Human Behaviour (2019), August 5 2019. https://www.nature.com/articles/s41562-019-0670-y

Abstract: Advances in robotics and artificial intelligence are increasingly enabling organizations to replace humans with intelligent machines and algorithms1. Forecasts predict that, in the coming years, these new technologies will affect millions of workers in a wide range of occupations, replacing human workers in numerous tasks2,3, but potentially also in whole occupations1,4,5. Despite the intense debate about these developments in economics, sociology and other social sciences, research has not examined how people react to the technological replacement of human labour. We begin to address this gap by examining the psychology of technological replacement. Our investigation reveals that people tend to prefer workers to be replaced by other human workers (versus robots); however, paradoxically, this preference reverses when people consider the prospect of their own job loss. We further demonstrate that this preference reversal occurs because being replaced by machines, robots or software (versus other humans) is associated with reduced self-threat. In contrast, being replaced by robots is associated with a greater perceived threat to one’s economic future. These findings suggest that technological replacement of human labour has unique psychological consequences that should be taken into account by policy measures (for example, appropriately tailoring support programmes for the unemployed).

Cognition in the fast lane: Ravens’ gaze duration are half as short as humans’ when choosing objects; their vision picks up more information per time unit

Bobrowicz, K., & Osvath, M. (2019). Cognition in the fast lane: Ravens’ gazes are half as short as humans’ when choosing objects. Animal Behavior and Cognition, 6(2), 81–97. https://doi.org/10.26451/abc.06.02.01.2019

Abstract: Time cannot be directly perceived; instead, its flow is inferred from the influx of sensory information. To prevent sensory overload, attentional mechanisms split up information into processable units. This portioning remains imperceptible to the individual. However, the length of these units still influences the speed of perception and the speed at which behaviors are performed. Previous studies have focused on establishing the length of these units in various mammalian species – mainly humans – by measuring different types of behaviors, including gaze. However, no such studies have been conducted on birds. We measured duration of ravens’ (Corvus corax) single gazes towards selectable objects before a choice was made, and compared it with that of humans in a similar set up. The raven gaze durations were approximately half those of humans (which fell slightly short of previously established ranges). We hypothesize that these differences are mainly due to the much higher so-called flicker-fusion-frequency in birds, which makes their vision faster in the sense that it picks up more information per time unit than mammalian vision does. We further discuss that the speed of perception might influence the general speed of cognitive processing in more complex tasks as well, and suggest that the addition of a temporal component in comparative cognitive studies might be informative.

KeywordsTime constant, Raven, Moment, Temporal processing, Cognition, Visual perception


A partner’s attractiveness enhances the perceived leadership of CEOs and this effect is mediated by CEO’s attractiveness; however, female CEOs’ leadership was downgraded in the presence of an attractive partner

Show Me Your Partner and I’ll Let You Know if You are a Leader. Ipek Kocoglu and Murad A. Mithani. Academy of Management ProceedingsVol. 2019, No. 1, Aug 1 2019. https://doi.org/10.5465/AMBPP.2019.13175abstract

Abstract: We integrate the research on evolutionary leadership with the evolutionary psychology of mate choice to investigate if the perception of an individual’s leadership capability is affected by the attractiveness of their partner. We argue that attractive partners signal unobservable leadership qualities, and accordingly, individuals are likely to be viewed more leader-like in the presence of an attractive partner than when seen alone. Study 1 found that a partner’s attractiveness enhances the perceived leadership of CEOs and this effect is mediated by CEO’s attractiveness. However, the benefits were limited to male CEOs. Female CEOs’ leadership was downgraded in the presence of an attractive partner. In study 2, we found that while the penalty for female CEOs increased when they were synthetically coupled with an attractive male, the spillover of partner’s attractiveness was positive for females that were perceived to be significantly more attractive than their partners. Our findings suggest that indirect cues that emanate from the partner are critical for leadership assessment. They invoke attributions that enhance the perceived leadership of males but largely disapprove of females as leaders.

Paying Back People Who Harmed Us but Not People Who Helped Us: Direct Negative Reciprocity Precedes Direct Positive Reciprocity in Early Development

Paying Back People Who Harmed Us but Not People Who Helped Us: Direct Negative Reciprocity Precedes Direct Positive Reciprocity in Early Development. Nadia Chernyak et al. Psychological Science, August 5, 2019. https://doi.org/10.1177/0956797619854975

Abstract: The principle of direct reciprocity, or paying back specific individuals, is assumed to be a critical component of everyday social exchange and a key mechanism for the evolution of cooperation. Young children know the norm of reciprocity, but it is unclear whether they follow the norm for both positive and negative direct reciprocity or whether reciprocity is initially generalized. Across five experiments (N = 330), we showed that children between 4 and 8 years of age engaged in negative direct reciprocity but generalized positive reciprocity, despite recalling benefactors. Children did not endorse the norm of positive direct reciprocity as applying to them until about 7 years of age (Study 4), but a short social-norm training enhanced this behavior in younger children (Study 5). Results suggest that negative direct reciprocity develops early, whereas positive reciprocity becomes targeted to other specific individuals only as children learn and adopt social norms.

Keywords: direct reciprocity, altruism, social groups, cognitive development, social norms, open data, open materials

Monday, August 5, 2019

Over the last 15 years, households have increasingly concentrated its spending on a few preferred products; not “superstar” products of large market shares; households increasingly focus spending on different products from each other

The Rise of Niche Consumption. Brent Neiman, Joseph Vavra. University of Chicago, July 2019. https://faculty.chicagobooth.edu/brent.neiman/research/NV.pdf

Abstract: We show that over the last 15 years, the typical household has increasingly concentrated its spending on a few preferred products. However, this is not driven by “superstar” products capturing larger market shares. Instead, households increasingly focus spending on different products from each other. As a result, aggregate spending concentration has in fact decreased over this same period. We use a novel heterogeneous agent model to conclude that increasing product variety is a key driver of these divergent trends. When more products are available, households can select a subset better matched to their particular tastes, and this generates welfare gains not reflected in government statistics. Our model features heterogeneous markups because producers of popular products care more about maximizing profits from existing customers, while producers of less popular niche products care more about expanding their customer base. Surprisingly, however,our model can match the observed trends in household and aggregate concentration without any resulting change in aggregate market power.

Keywords: Product Concentration, Niche Products, Market Power, Markups, Long-tail


On the potential distortions of highly cited papers in emerging research fields: A critical appraisal

On the potential distortions of highly cited papers in emerging research fields: A critical appraisal. Edoardo G. Ostinelli, Orsola Gambini and Armando D'Agostino. Behavioral and Brain Sciences, Volume 42, 2019, e77. July 15 2019. https://doi.org/10.1017/S0140525X18002807

Abstract: Citation-based metrics are increasingly used as a proxy to define representative, considerable, or significant papers. We challenge this belief by taking into account factors that may play a role in providing citations to a manuscript and whether/how those highly cited studies could shape a scientific field. A different approach to summarisation of relevant core publications within a topic is proposed.

One reason for the high usage of sexually explicit material might be the rewarding property demonstrated in many studies showing an activation of the reward system during the presentation; no sex differences

No Sex Difference Found: Cues of Sexual Stimuli Activate the Reward System in both Sexes. Rudolf Stark et al. Neuroscience, August 5 2019. https://doi.org/10.1016/j.neuroscience.2019.07.049

Highlights
•    SEM cues resulted in similar neural activations as the presentation of SEM
•    The neural responses towards cues did not differ between men and women
•    There were some sex differences in the neural responses towards SEM
•    The nucleus accumbens response was unaffected by person characteristics

Abstract: Sexually explicit material (SEM) is increasingly used in western societies. One reason for this high usage might be the rewarding property of SEM demonstrated in many brain imaging studies showing an activation of the reward system during the presentation of SEM. It is not yet well understood why women use SEM to a remarkably lesser extent than men. Maybe men react stronger to stimuli – so called SEM cues –, which signal the presentation of SEM and are therefore more vulnerable to use SEM than women. Therefore, the present study aimed at investigating the sex specific neural correlates towards SEM and SEM cues. We were further interested in whether person characteristics as trait sexual motivation, extent of SEM use in the last month, and age at onset of goal-oriented SEM use affect the neural responses to SEM and SEM cues. The trials of the fMRI experiment consisted of an expectation phase with SEM or neutral cues and a presentation phase with SEM or neutral stimuli, respectively. Analyses showed that the reward circuitry was activated by SEM, but also by SEM cues. There were some sex differences in hemodynamic responses to SEM during the presentation phase, but not during the expectation phase to SEM cues in any of the regions of interest. The influence of the investigated person characteristics was only small if existent. The results suggest that sex specific cue processing cannot explain sex differences in the use of SEM.

Urban China: Tenure change from renter to owner significantly increased subjective well-being; the effect was unaffected by the financial burdens of new homeowners

Does happiness dwell in an owner-occupied house? Homeownership and subjective well-being in urban China. Xian Zheng, Zi-qing Yuan, XiaolingZhang. Cities, Volume 96, January 2020, 102404. https://doi.org/10.1016/j.cities.2019.102404

Highlights
• We investigated the causal effect of homeownership on subjective well-being.
• The causal relationship was estimated using the difference-in-differences approach.
• Tenure change from renter to owner significantly increased subjective well-being.
• The causal effect was unaffected by the financial burdens of new homeowners.

Abstract: This study investigates the causal relationship between homeownership and subjective well-being based on household-level panel data collected from the China Household Finance Survey (CHFS) in 2011 and 2013. The extent to which homeownership contributes to the changes in subjective well-being is estimated, focusing on the heterogeneous effects across socioeconomic and demographic groups. Evidence from the identification strategies indicates that homeownership has a positive impact on subjective well-being. Moreover, the results are robust to different specifications and unaffected by the financial constraints faced by new homeowners. Our findings have useful implications for policymakers to stimulate homeownership rates to promote subjective well-being.

Keywords: Subjective well-beingHomeownershipDifference-in-DifferencesUrban China


Austin, Denver, & Portland have thriving 21st century economies, but families with children struggle to take advantage of what they offer; there is a link between gentrification & loss of children over time

Is there room for children in booming western cities? Empirical evidence from Austin, Denver, and Portland. JakeWegmann. Cities, Volume 96, January 2020, 102403. https://doi.org/10.1016/j.cities.2019.102403

Highlights
• Austin, Denver, and Portland have thriving 21st century economies.
• However, families with children struggle to take advantage of what they offer.
• There is a link between gentrification and loss of children over time.
• Single-family and missing middle housing types are key for retaining children.
• They and other cities need to specifically prioritize housing needs of children.

Abstract: Austin, Denver, and Portland are all booming cities in or on the edge of the American West. Their thriving economies and natural and urban amenities have attracted large numbers of in-migrants. As housing prices rise, families with children in particular face diminished choices about where to live. This article asks three questions: How have the child populations of Austin, Denver, and Portland fared in recent decades? Is there a link between gentrification and a decrease in family households with children? And finally, to what extent do various housing types associate with more or fewer of these households? In brief, Austin, Denver, and Portland have fared reasonably well in maintaining family life, but neighborhoods with master-planned brownfield or greenfield developments appear to have accounted for a disproportionate share of the growth in their child populations, helping to offset sharp losses in gentrifying neighborhoods closer to the cities' urban cores. As these opportunities begin to diminish in all three cities, the strong association between compact single-family and “missing middle,” or middle density, housing types and households with children suggests pathways for these three cities and others like them to retain such households, by using policy to encourage these development types.

Keywords: ChildrenMissing middle housingAffordable housingGentrificationAmerican west

Does exposure to richer and poorer neighborhoods influence wellbeing? Individuals with higher income than that of neighbors are more satisfied with life

Does exposure to richer and poorer neighborhoods influence wellbeing? Donggen Wang, Tim Schwanen, Zidan Mao. Cities, Volume 95, December 2019, 102408, https://doi.org/10.1016/j.cities.2019.102408

Highlights
• Examines the impacts of individuals' income vis-à-vis that of neighbors on life satisfaction
• Studies the effect of individuals' income vis-à-vis that of visited areas on emotional wellbeing
• Data are derived from an activity-travel diary survey conducted in 2010 in Hong Kong
• Individuals with higher income than that of neighbors are more satisfied with life
• Individuals' income vis-à-vis that of visited areas is a positive predictor of emotional wellbeing

Abstract: Geographical differences in wellbeing have attracted increased attention in the science of happiness literature and recent research has become particularly interested in high-resolution spatial differentiation within cities. This study contributes to this literature by analyzing the relationships between subjective wellbeing and relative income at the neighborhood level using activity-travel survey data from 2010 in Hong Kong. In contrast to previous studies, the analysis concentrates not only on life satisfaction but also on pleasure derived from daily activities in the city, and considers relative income in people's residential neighborhood and the neighborhoods where they conduct different types of daily activity. The results suggest that social comparisons with regard to income matter to life satisfaction as well as emotional wellbeing, that the effects occur for both the residential neighborhood and the urban places where daily activities are undertaken, and that downward income comparisons tend to have stronger effects on wellbeing than upward comparison. One theoretical implication that follows from the analysis is that the impact of social comparison in the science of happiness needs to be theorized as dynamic, mobile and contingent upon people's daily trajectories through time and urban space.

Keywords: Hong KongIncomeLife satisfactionNeighborhoodPleasureSocial comparisonWellbeing

Let There Be Variance: Individual Differences in Consecutive Self‐control in a Laboratory Setting and Daily Life

Let There Be Variance: Individual Differences in Consecutive Self‐control in a Laboratory Setting and Daily Life. Mario Wenzel et al. European Journal of Personality, June 23 2019. https://doi.org/10.1002/per.2208

Abstract: The large body of research used to support ego‐depletion effects is currently faced with conceptual and replication issues, leading to doubt over the extent or even existence of the ego‐depletion effect. By using within‐person designs in a laboratory (Study 1; 187 participants) and an ambulatory assessment study (Study 2; 125 participants), we sought to clarify this ambiguity by investigating whether prominent situational variables (such as motivation and affect) or personality traits can help elucidate when ego depletion can be observed and when not. Although only marginal ego‐depletion effects were found in both studies, these effects varied considerably between individuals, indicating that some individuals experience self‐control decrements after initial self‐control exertion and others not. However, neither motivation nor affect nor personality traits such as trait self‐control could consistently explain this variability when models were applied that controlled for variance due to targets and the depletion manipulation (Study 1) or days (Study 2) as well as for multiple testing. We discuss how the operationalization and reliability of our key measures may explain these null effects and demonstrate that alternative metrics may be required to study the consequences of the consecutive exertion of self‐control.

These results show that upright animals, regardless of whether they are predators or prey, attract attention in humans, & this could allow humans to rapidly evaluate predatory threats or the flight readiness of hunted game

Animals in Upright Postures Attract Attention in Humans. Jessica L. Yorzinski, Richard G. Coss. Evolutionary Psychological Science, August 5 2019. https://link.springer.com/article/10.1007/s40806-019-00209-w

Abstract: Individual predators differ in the level of risk they represent to prey. Because prey incur costs when responding to predators, prey can benefit by adjusting their antipredator behavior based on the level of perceived risk. Prey can potentially assess the level of risk by evaluating the posture of predators as an index of predators’ motivational state. Like other prey species, humans might evaluate predator body posture as a prominent cue for assessing danger. We tested whether human participants adjusted their visual attention based on the postures of predators by presenting participants with photographic arrays of predators (lions) that varied in postures while we recorded the participants’ gaze behavior. The participants searched for a standing lion (representing a high-risk target) among an array of reclining lions (representing low-risk distractors) or searched for a reclining lion among an array of standing lions. They also searched through similar arrays consisting of non-threatening prey (impalas) standing or reclining, rather than predators. Participants detected standing lions and impala faster than reclining lions and impala. Surprisingly, they detected standing lions at similar latencies as standing impala. They detected the reclining lions and impala more slowly because they spent more time looking at the standing lion and impala distractors and looked at more of those distractors. These results show that upright animals, regardless of whether they are predators or prey, attract attention in humans, and this could allow humans to rapidly evaluate predatory threats or the flight readiness of hunted game.

Keywords: Attention Humans Delayed disengagement Posture Predator detection

Is Well-being Associated with the Quantity and Quality of Social Interactions? Introverts may experience greater boosts in social connectedness, relative to extraverts, when engaging in deeper conversations

Sun, Jessie, Kelci Harris, and Simine Vazire. 2019. “Is Well-being Associated with the Quantity and Quality of Social Interactions?.” PsyArXiv. August 5. doi:10.31234/osf.io/xdvsa

Abstract: Social relationships are often touted as critical for well-being. However, the vast majority of studies on social relationships have relied on self-report measures of both social interactions and well-being, which makes it difficult to disentangle true associations from shared method variance. To address this gap, we assessed the quantity and quality of social interactions using both self-report and observer-based measures in everyday life. Participants (N = 256, 3,206 observations) wore the Electronically Activated Recorder (EAR), an unobtrusive audio recorder, and completed experience sampling method (ESM) self-reports of their momentary social interactions, happiness, and feelings of social connectedness, four times each day for one week. Observers rated the quantity and quality of participants’ social interactions based on the EAR recordings from the same time points. Quantity of social interactions was robustly associated with greater well-being in the moment and on average, whether they were measured with self-reports or observer reports. Conversational (conversational depth and self-disclosure) and relational (knowing and liking one’s interaction partners) aspects of social interaction quality were also generally associated with greater well-being, but the effects were larger and more consistent for self-reported (vs. observer-reported) quality variables, within-person (vs. between-person) associations, and for predicting social connectedness (vs. happiness). Finally, although most associations were similar for introverts and extraverts, our exploratory results suggest that introverts may experience greater boosts in social connectedness, relative to extraverts, when engaging in deeper conversations. This study provides compelling multi-method evidence supporting the link between more frequent and deeper social interactions and well-being.

Sunday, August 4, 2019

From 2018: Genetic Endowments and Wealth Inequality

From 2018: Genetic Endowments and Wealth Inequality. Daniel Barth, Nicholas W. Papageorge, Kevin Thom. NBER Working Paper No. 24642, May 2018. https://nicholaswpapageorge.files.wordpress.com/2018/05/genes_wealth.pdf

Abstract: We show that genetic endowments linked to educational attainment strongly and robustly predict wealth at retirement. The estimated relationship is not fully explained by flexibly controlling for education and labor income. We therefore investigate a host of additional mechanisms that could help to explain the gene-wealth gradient, including inheritances, mortality, savings, risk preferences, portfolio decisions, beliefs about the probabilities of macro economic events, and planning horizons. The associations we report provide preliminary evidence that genetic endowments related to human capital accumulation are associated with wealth not only through educational attainment and labor income, but also through a facility with complex financial decision-making. Our study illustrates how economic research seeking to understand sources of inequality can benefit from recent advances in behavioral genetics linking specific observed genetic endowments to economic outcomes.
Keywords: Wealth, Inequality, Portfolio Decisions, Beliefs, Education and Genetics

Genetic & environmental sources of individual differences in homophobic tendencies towards gay men: A large proportion of genetic factors (82%) contribute to individual differences in homophobia

Sources of Individual Differences in Sociopolitical Orientations: Findings from Combining Behavior Genetic with Multi-Rater Approaches. Alexandra Zapko-Willmes. Kumulative Dissertation zur Erlangung des akademischen Grades Dr. rer. nat. im Fach Psychologie, Universität Bielefeld. Oct 2018. http://pub.uni-bielefeld.de/download/29325

Summary
In the three studies constituting this dissertation, behavior genetic and multi-rater approaches were combined to contribute to the understanding of sources of interindividual differences in broad and narrow dimensions of sociopolitical orientations. For this purpose, all studies employed structural equation modeling designs based on cross-sectional twin family and multi-rater data from the Jena Twin Study of Social Attitudes (JeTSSA; studies 1 and 2) and the Study of Personality Architecture and Dynamics (SPeADy; study 3).

Study 1 was aimed at validating and extending previous self-report studies on genetic and environmental sources of individual differences in homophobic tendencies towards gay men across multiple rater perspectives. In line with our hypotheses, we found a large proportion of genetic factors (82%) to contribute to individual differences in homophobia, with unique environmental factors (18%) explaining the remaining variance. Moreover, we found variance specific for self-reports to be partially attributable to genetic factors (20%), confirming past findings that suggested that self-reports may underlie genetic influences. Results indicate the importance of univariate behavior genetic investigations.

Study 2 was conducted to examine, whether differences in experienced parenting affect present differences in twin sibling’s right-wing authoritarianism (RWA) via a “truly” environmental pathway as opposed to a genetic mediation. We integrated genetically informed and phenotypic multi-rater models to investigate whether and how the association is confounded due to shared genetic and environmental sources of both variables. We considered offspring’s, mothers’, and fathers’ retrospective ratings of two parenting dimensions and offspring’s self- and informant reports on their RWA. Our hypotheses were generally not confirmed. An evocative genotype-environment correlation likely explained the positive link between parental responsiveness and differences in offspring’s RWA. In other words, the offspring’s genetically influenced RWA score (and associated behavior) affected their experienced parental emotional warmth and support, with a higher RWA score associated with more highly experienced responsiveness. In contrast, we found an effectively environmental positive association between differences in experienced parental demandingness and differences in twin sibling’s RWA. Parental RWA, while not associated with parental responsiveness, partly explained the link between experienced demandingness and differences in offspring’s RWA.  Findings underlined the additional insight gained through multiple raters on the environmental as well as characteristic.

Finally, study 3 examined the convergence of basic value orientations and foci of moral concern as two abstract dimensions of sociopolitical orientations. We expected the dimensions to converge based on common underlying world beliefs. The value orientation towards conservation versus openness to change was expected to converge with a moral focus on organization versus opportunity due to the underlying belief in a dangerous world. The value orientation self-transcendence versus self-enhancement was expected to converge with a moral focus on social versus individual outcomes due to the underlying (lack of) belief in a competitive world. We combined multi-rater with twin family data to investigate four criteria of convergence (structural, age-related, source-related, and the link with a key personality trait). For both expected links, we found the dimensions to be systematically linked, but reflect distinct characteristics, suggesting that they reflect characteristics of different personality layers. We discussed the role of specific motives and environmental factors contributing to differences in foci of moral concern.


Introduction
According to an old saying and etiquette rule1, one should avoid conversations about political topics, alluding to the inevitably ensuing disputes fueled by individual differences in social and political views. When viewed through historic and current events, these interindividual differences may have major individual-level, group-level, societal, and even global consequences beyond mere heated disputes. Individual preferences regarding social and political issues, subsumed under the term sociopolitical orientations, have been linked to various forms of prejudice (Altemeyer, 1996; Asbrock, Sibley, & Duckitt, 2010; Duckitt & Farre, 1994; Ekehammar, Akrami, Gylje, & Zakrisson, 2004; Hodson & Dhont, 2015), support for radical right parties (Aichholzer & Zandonella, 2016; Cornelis & Van Hiel, 2015; but see also Dunn, 2015), endorsement of human rights and associated behavior (Cohrs, Maes, Moschner, & Kielmann, 2007), and post-9/11 attitudes (Crowson, DeBacker, & Thoma, 2005, 2006), to name a few. Furthermore, its impact could be recently observed in the context of political participation and voting behavior in the Brexit referendum (Golec de Zavala, Guerra, & Simão, 2017) as well as the US presidential election (Choma & Hanoch, 2017; Womick, Rothmund, Azevedo, King, & Jost, 2018).

These findings corroborate the importance of research on the factors that contribute to individual differences in sociopolitical orientations. An important piece of this puzzle is the identification of the biological and environmental roots of these characteristics. These roots have long been regarded as being essentially – even exclusively – environmental; Genetic explanations were largely disregarded in favor of socialization explanations (e.g., Adorno, Frenkel-Brunswik, Levinson, & Sanford, 1950; Altemeyer, 1988). However, behavior genetic studies (e.g., Eaves & Eysenck, 1974; Eaves et al., 1999; Kandler, Bleidorn, & Riemann, 2012; Martin et al., 1986) have shown that environmental factors shared between twin siblings (which would reflect a large portion of the argued socialization) are not as crucial as previously assumed, and that genetic and idiosyncratic environmental effects are substantial. After decades of neglecting genetic explanations, there is no longer a “nature versus nurture” debate when it comes to sources of individual differences in sociopolitical orientations, as well as other personality characteristics2 and virtually all complex human dispositions (Polderman et al., 2015). Rather, nature and nurture are agreed to be interwoven with each other (Plomin, DeFries, & Loehlin, 1977; Scarr & McCartney, 1983). 

In this work, I sought to contribute to the understanding of the sources of interindividual differences in sociopolitical orientations. Sociopolitical orientations were studied at various levels of content-related abstraction (Section I), ranging from specific dimensions (i.e., homophobia; study 1), to broad, less specific dimensions that capture individual global social and political preferences (i.e., right-wing authoritarianism; study 2) to even more abstract motivational and affective-cognitive dimensions (i.e., value orientations and foci of moral concern; study 3). I employed both behavior genetic and multi-rater models to overcome methodological limitations (Section II) of past univariate (study 1) and multivariate (study 2) behavior genetic research, and to gain insight into the convergence of two conceptually related dimensions of sociopolitical orientations (study 3).

Homosexual consumers show negative responses to heterosexual imagery; doesn't happen in the opposite direction

Consumer Responses to Homosexual Imagery in Advertising: A Meta-Analysis. Martin Eisend & Erik Hermann. Journal of Advertising, Jul 17 2019. https://doi.org/10.1080/00913367.2019.1628676 

Abstract: Rising support for the lesbian, gay, bisexual, and transgender (LGBT) community, paired with the considerable buying power of this group, has triggered increasing interest from marketers in the gay and lesbian market. Many companies have developed advertising with homosexual imagery to better target this group as well as the mainstream market. The findings on the persuasive effects of homosexual imagery are mixed and do not provide insights on whether and when homosexual imagery in advertising supports persuasion. To resolve the inconsistencies in findings of prior research, this article presents a meta-analysis on the effects of homosexual imagery. The integrated effect size suggests that the net persuasive effect between homosexual and heterosexual imagery does not differ. We find, however, that homosexual consumers show negative responses to heterosexual imagery. Furthermore, the moderator analysis suggests that incongruence between imagery, consumer characteristics, cultural values, explicitness of imagery, endorser gender, and product type results in unfavorable responses to homosexual advertising imagery. These findings provide guidelines for future research and implications for advertisers who intend to address consumers of various sexual orientations.

Functional connectivity shows age-related increases within resting-state networks & age-related decreases between them; genetic influences on functional connectivity remain stable throughout adolescence

Genetic and environmental influences on functional connectivity within and between canonical cortical resting-state networks throughout adolescent development in boys and girls. Jalmar Teeuw et al. NeuroImage, August 3 2019, 116073. https://doi.org/10.1016/j.neuroimage.2019.116073

Highlights
• We studied resting-state networks in a longitudinal adolescent twin-sibling sample.
• Functional connectivity shows age-related increases within resting-state networks.
• Functional connectivity shows age-related decreases between resting-state networks.
• Reliability modelling improves sensitivity to detect familial influences.
• Genetic influences on functional connectivity remain stable throughout adolescence.

Abstract: The human brain is active during rest and hierarchically organized into intrinsic functional networks. These functional networks are largely established early in development, with reports of a shift from a local to more distributed organization during childhood and adolescence. It remains unknown to what extent genetic and environmental influences on functional connectivity change throughout adolescent development. We measured functional connectivity within and between eight cortical networks in a longitudinal resting-state fMRI study of adolescent twins and their older siblings on two occasions (mean ages 13 and 18 years). We modelled the reliability for these inherently noisy and head-motion sensitive measurements by analyzing data from split-half sessions. Functional connectivity between resting-state networks decreased with age whereas functional connectivity within resting-state networks generally increased with age, independent of general cognitive functioning. Sex effects were sparse, with stronger functional connectivity in the default mode network for girls compared to boys, and stronger functional connectivity in the salience network for boys compared to girls. Heritability explained up to 53% of the variation in functional connectivity within and between resting-state networks, and common environment explained up to 33%. Genetic influences on functional connectivity remained stable during adolescent development. In conclusion, longitudinal age-related changes in functional connectivity within and between cortical resting-state networks are subtle but wide-spread throughout adolescence. Genes play a considerable role in explaining individual variation in functional connectivity with mostly stable influences throughout adolescence.

Keywords: LongitudinalTwinsHeritabilityAge effectsSex effects

A Decline in Propensity Toward Risk Behaviors Among US Adolescents

Borodovsky, Jacob and Krueger, Robert F. and Agrawal, Arpana and Grucza, Richard, A Decline in Propensity Toward Risk Behaviors Among US Adolescents (June 14, 2019). Available at SSRN, http://dx.doi.org/10.2139/ssrn.3403870

Abstract
Purpose: Over the past two decades, substance use, delinquent behaviors, and promiscuous sexual activity have declined substantially among U.S. adolescents. We aimed to determine the extent to which these trends represent declines in a general propensity to engage in risk behaviors (i.e., declines in a latent factor).
Methods: We used Youth Risk Behavior Survey data (1999-2017) (n=147,800) and examined trends in substance use (e.g., alcohol) delinquency (e.g., fighting), and sexual activity (e.g., number of partners). We conducted two types of analyses stratified by grade (9th/10th vs. 11th/12th) and sex: (1) estimation of year-specific prevalence of each behavior and modeled prevalence changes over time; (2) factor analysis and application of alignment methods to determine changes in the mean of the latent factor over time while correcting for measurement non-invariance.
Results: A single factor explained 53% (girls 11th/12th grade) to 62% (boys 9th/10th grade) of the variance in risk behaviors. Average relative annual declines in the prevalence of each behavior—except for weapon carrying—ranged from 1-6%. The structure of the latent factor was mostly unchanged over time, with notable exceptions related to differential changes in prevalence for cigarette and cannabis use. Between 1999 and 2017, the mean of the latent factor declined by between 0.54 and 0.73 standard deviations.
Conclusions: Results suggest that much of the decline in the prevalence of substance use, delinquent, and sexual behaviors among American youth from 1999-2017 reflect an approximately two-thirds standard deviation decline in the mean of a latent risk behavior factor.

Saturday, August 3, 2019

Links between distress & time perception suggest the possibility of downward spirals during stressful waiting periods, such that distress makes time seem to slow down, which then exacerbates distress

Associations between Subjective Time Perception and Well‐Being during Stressful Waiting Periods. Kyla Rankin  Kate Sweeny  Sandra Xu. Stress & Health, August 2 2019, https://doi.org/10.1002/smi.2888

Abstract: The passage of time is a subjective experience and can be easily distorted by concurrent emotions. Specifically, time seems to move particularly slowly when people are in a negative emotional state. The aim of the current studies was to evaluate the bidirectional relationship between subjective time perception and distress during stressful waiting periods, during which the slow passage of time may be particularly distressing. Across studies of undergraduate students awaiting a midterm exam grade (Study 1) and law graduates awaiting bar exam results (Studies 2 and 3), results revealed consistent links between distress and time perception across the waiting periods, with tentative evidence for bidirectional relationships between these experiences. That is, people who perceived time as moving slowly while they waited tended to report greater distress across the waiting period (particularly worry, anxiety, negative emotion, and poor coping), and people who reported greater distress tended to perceive time as moving more slowly. The links between distress and time perception suggest the possibility of downward spirals during stressful waiting periods, such that distress makes time seem to slow down, which then exacerbates distress. We discuss avenues for future research and potential remedies to derail the spiral of distress and time perception.


Techniques have been identified that can modify memories at both stages of initial storage and re-storage, but implementation into clinical therapies has produced inconsistent benefits

Memory editing from science fiction to clinical practice. Elizabeth A. Phelps & Stefan G. Hofmann. Nature, volume 572, pages 43–50 (2019). July 31 2019, https://www.nature.com/articles/s41586-019-1433-7

Abstract: Science fiction notions of altering problematic memories are starting to become reality as techniques emerge through which unique memories can be edited. Here we review memory-editing research with a focus on improving the treatment of psychopathology. Studies highlight two windows of memory vulnerability: initial storage, or consolidation; and re-storage after retrieval, or reconsolidation. Techniques have been identified that can modify memories at each stage, but translating these methods from animal models to humans has been challenging and implementation into clinical therapies has produced inconsistent benefits. The science of memory editing is more complicated and nuanced than fiction, but its rapid development holds promise for future applications.

J‐curve association between alcohol intake and varicose veins in Japan: The Shimane CoHRE Study

J‐curve association between alcohol intake and varicose veins in Japan: The Shimane CoHRE Study. Kunie Kohno  Hiroyuki Niihara  Tsuyoshi Hamano  Miwako Takeda  Yusei Nakagawa  Kuninori Shiwaku  Toru Nabika  Bengt Zöller  Xinjun Li  Kristina Sundquist  Jan Sundquist  Eishin Morita. Concise Communication, July 29 2019 https://doi.org/10.1111/1346-8138.15022

Abstract: The effect of alcohol intake on varicose veins (VV) has not been determined by its consumption level. The aim of this study was to investigate the association between alcohol intake and VV in an elderly general population. Using a cross‐sectional approach, the Shimane CoHRE Study data, comprising a total of 1060 participants, were analyzed. By multivariate regression analysis adjusted with basic characteristics, past work history, lifestyle‐related factors and medical history, compared with non‐drinkers, mild drinkers (<20.0 g/day) showed a significantly lower adjusted odds ratio (aOR) of VV (aOR = 0.64, P = 0.036). In a similar way, regular drinkers (1–5 days/week) showed a significantly lower aOR of VV when compared with occasional drinkers (aOR = 0.57, P = 0.032). VV and alcohol intake showed J‐curve relationships. In a stratified analysis by alcohol consumption levels, the association of smoking and VV were also observed in moderate to heavy drinkers and habitual drinkers. These findings can provide better understanding of pathophysiological mechanism and be used for evidence‐based patient education.


Re-analysis of data reveals no evidence for neonatal imitation in rhesus macaques

Re-analysis of data reveals no evidence for neonatal imitation in rhesus macaques. Jonathan Redshaw. Biology Letters, July 24 2019, https://doi.org/10.1098/rsbl.2019.0342

Abstract: Over the past decade, a growing number of publications have claimed to provide evidence for the existence and function of neonatal imitation in rhesus macaques. Here I show that there is in fact no empirical basis for these claims. Studies of the phenomenon have consistently failed to implement the gold standard cross-target analytical approach, which controls for increases in matching responses that may not be a function of the specific modelled behaviour. Critically, a pre-registered re-analysis of the entire set of existing data using this cross-target approach shows that macaque neonates have failed to produce matching tongue protrusion or lipsmacking responses at levels greater than chance. Furthermore, there is no evidence for intra-individual consistency in ‘imitative’ responses across different actions, as imitation scores for the two actions are negatively correlated with each other. Macaque tongue protrusion and lipsmacking responses may vary as a function of general factors that fluctuate over testing sessions, rather than as a function of the specific model or of between-individual variations in imitative tendencies.

Social media comparisons: More likely to be upward than downward, & making more frequent & more extreme upward comparisons yielded greater declines in self-evaluations, mood, & life satisfaction

When Every Day is a High School Reunion: Social Media Comparisons and Self-esteem. Claire Midgley. Psychology School, Toronto Univ. PhD Thesis, Jun 2019. http://hdl.handle.net/1807/95911

Abstract: Although past research has shown that social comparisons made through social media contribute to negative outcomes, little is known about the nature of these comparisons (e.g., domains, direction, and extremity), variables that determine the outcomes of these comparisons (e.g., post valence, perceiver’s self-esteem), and how these comparisons differ from those made in other contexts (e.g. while texting or interacting face to face). In five studies (N=900), I provide the first comprehensive analysis of how individuals make and respond to social comparisons on two different social media platforms (Facebook and Instagram), using comparisons made in real-time while participants browsed their own social media news feeds (Studies 1 and 3), experimenter-generated social media content (Study 2), and reports of comparisons made in various contexts, including social media (Studies 4 and 5). I found that individuals made frequent upward comparisons on social media. Further, social media comparisons were more likely to be upward than downward, and making more frequent and more extreme upward comparisons on social media resulted in greater declines in self-evaluations, mood, and life satisfaction. In addition, individuals with lower self-esteem made more frequent and extreme upward comparisons while browsing social media, resulting in even steeper declines in self-evaluations. Finally, compared to upward comparisons in other contexts, those made on social media were more often to distant (vs. close) targets, more likely to be image-based, and resulted in greater declines in self-evaluations. Together, these studies provide the first insights into the cumulative impact of multiple social comparisons, demonstrate the unique nature of social comparisons made on social media, and clarify the role of self-esteem in online social comparison processes.

Keywords: self-esteem; social comparison; social media

Evaluating the evidential value of empirically supported psychological treatments (ESTs): Failing to strengthen efficacy

Sakaluk, J. K., Williams, A. J., Kilshaw, R. E., & Rhyner, K. T. (2019). Evaluating the evidential value of empirically supported psychological treatments (ESTs): A meta-scientific review. Journal of Abnormal Psychology, 128(6), 500-509. http://dx.doi.org/10.1037/abn0000421

Abstract: Empirically supported treatments (or therapies; ESTs) are the gold standard in therapeutic interventions for psychopathology. Based on a set of methodological and statistical criteria, the APA has assigned particular treatment-diagnosis combinations EST status and has further rated their empirical support as Strong, Modest, and/or Controversial. Emerging concerns about the replicability of research findings in clinical psychology highlight the need to critically examine the evidential value of EST research. We therefore conducted a metascientific review of the EST literature, using clinical trials reported in an existing online APA database of ESTs, and a set of novel evidential value metrics (i.e., rates of misreported statistics, statistical power, R-Index, and Bayes Factors). Our analyses indicated that power and replicability estimates were concerningly low across almost all ESTs, and individually, some ESTs scored poorly across multiple metrics, with Strong ESTs failing to continuously outperform their Modest counterparts. Lastly, we found evidence of improvements over time in statistical power within the EST literature, but not for the strength of evidence of EST efficacy. We describe the implications of our findings for practicing psychotherapists and offer recommendations for improving the evidential value of EST research moving forward.

Participants increased in well-being when they were assigned to act extraverted & decreased when they were assigned to act introverted; changing behavior associated with personality is possible

Margolis, S., & Lyubomirsky, S. (2019). Experimental manipulation of extraverted and introverted behavior and its effects on well-being. Journal of Experimental Psychology: General. http://dx.doi.org/10.1037/xge0000668

Abstract: Research in personality psychology has remained predominantly correlational. For example, 3 decades of research demonstrate a robust cross-sectional relationship between extraversion and positive affect. A handful of studies, however, have examined this link experimentally, showing that extraversion boosts positive affect over short durations. If this is true, behaving in an extraverted manner should be a reliable method for increasing positive affect and, thus, suitable as a well-being-increasing practice. The current study instructed participants to engage in both extraverted and introverted behavior, each for 1 week. Participants increased in well-being when they were assigned to act extraverted and decreased in well-being when they were assigned to act introverted. These findings suggest that changing behavior associated with personality is possible and can impact well-being. More broadly, this study adds to a growing body of research on the potential of experimental methods in personality psychology.


The influential hypothesis that humans imitate from birth – and that this capacity is foundational to social cognition – is currently being challenged from several angles

Individual differences in neonatal ‘imitation' fail to predict early social cognitive behaviour. Jonathan Redshaw  Mark Nielsen  Virginia Slaughter  Siobhan Kennedy‐Costantini  Janine Oostenbroek  Jessica Crimston  Thomas Suddendorf. Developemental Science, August 1 2019, https://doi.org/10.1111/desc.12892 

Abstract: The influential hypothesis that humans imitate from birth – and that this capacity is foundational to social cognition – is currently being challenged from several angles. Most prominently, the largest and most comprehensive longitudinal study of neonatal imitation to date failed to find evidence that neonates copied any of nine actions at any of four time points (Oostenbroek et al., 2016). The authors of an alternative and statistically liberal post‐hoc analysis of these same data (Meltzoff et al., 2017), however, concluded that the infants actually did imitate one of the nine actions: tongue protrusion. In line with the original intentions of this longitudinal study, we here report on whether individual differences in neonatal ‘imitation' predict later‐developing social cognitive behaviours. We measured a variety of social cognitive behaviours in a subset of the original sample of infants (N = 71) during the first 18 months: object‐directed imitation, joint attention, synchronous imitation, and mirror self‐recognition. Results show that, even using the liberal operationalisation, individual scores for neonatal ‘imitation' of tongue protrusion failed to predict any of the later‐developing social cognitive behaviours. The average Spearman correlation was close to zero, mean rs = .027, 95% CI [‐.020, .075], with all Bonferroni adjusted p values > .999. These results run counter to Meltzoff et al.'s rebuttal, and to the existence of a “like me” mechanism that is foundational to human social cognition.


Friday, August 2, 2019

Sibling analysis of 232 mice: Twins were exposed to either enriched or impoverished environments; enrichment was associated with an increase in the heritability of some personality & cognitive traits

Mouse twins separated when young: A history of exploration doubles the heritability of boldness and differentially affects the heritability of measures of learning. Louis D. Matzel et al. Intelligence, Volume 74, May–June 2019, Pages 34-42. https://doi.org/10.1016/j.intell.2019.01.005

Highlights
• A sibling analysis of 232 mice assessed the sensitivity of heritability to environmental history
• Twins were exposed to either enriched or impoverished environments
• Learning, physical, and personality traits were all heritable
• Environmental enrichment was associated with an increase in the heritability of some personality and cognitive traits
• Estimates of heritability can be sensitive to manipulation of environmental history

Abstract: Most quantifiable traits exhibit some degree of heritability. The heritability of physical traits is often high, but the heritability of some personality traits and intelligence can also be highly heritable. Importantly, estimates of heritability can change dramatically depending on such variables as the age or the environmental history of the sample from which the estimate is obtained. Interpretation of these changing estimates is complicated in studies of humans, where (based on correlational observations) environmental variables are hard to directly control or specify. Using laboratory mice, here we could control specific environmental variables. We assessed 58 groups of four full sibling male CD-1 genetically heterogeneous mice (n = 232). Using a standard full-sibling analysis, physical characteristics (body weight and brain weight) were highly heritable (h of body weight = 0.66 on a 0–1 scale), while behaviors indicative of a personality trait (exploration/boldness) and learning abilities (in a passive avoidance and egocentric maze task) were weakly-to-moderately heritable. Half of the siblings from each set of four were housed in an “enriched” environment, which provided extensive and varied opportunities for exploration. This enrichment treatment promoted improvements in learning and a shift toward a more bold personality type. Relative to animals in control (“impoverished” environments), the history of enrichment had significant impact on estimates of heritability. In particular, the heritability of behaviors related to the personality trait (exploration/boldness) more than doubled, and a similar increase was observed for learning (in the passive avoidance task). Physical traits (brain and body weight), however, were insensitive to environmental history (where in both environments, animals received the same diet). These results indicate that heritable traits can be responsive to variations in the environment, and moreover, that estimates of heritability of learning and personality traits are strongly influenced by environments that modulate those traits.

Keywords: HeritabilityLearningEnvironmental enrichmentBoldnessBody weightBrain weight