Friday, December 14, 2018

Affirmative action lowers the performance of high-ability women and increases the performance of low-ability women; possible mechanisms—AA changes incentives differentially for low- and high-ability women, or AA triggers stereotype threat

The heterogeneous effect of affirmative action on performance. Anat Bracha, Alma Cohen, LynnConell-Price. Journal of Economic Behavior & Organization,

Abstract: This paper experimentally investigates the effect of gender-based affirmative action (AA) on performance in the lab, focusing on a tournament environment. The tournament is based on GRE math questions commonly used in graduate school admission, and at which women are known to perform worse on average than men. We find heterogeneous effect of AA on female participants: AA lowers the performance of high-ability women and increases the performance of low-ability women. Our results are consistent with two possible mechanisms—one is that AA changes incentives differentially for low- and high-ability women, and the second is that AA triggers stereotype threat.

Guilt-proneness predicts trustworthiness better than a variety of other personality measure; people high in guilt-proneness are more likely to behave in interpersonally sensitive ways when they are more responsible for others’ outcomes

Levine, Emma, Brad Bitterly, Taya R. Cohen, and Maurice Schweitzer. 2018. “Who Is Trustworthy? Predicting Trustworthy Intentions and Behavior.” PsyArXiv. December 14. doi:10.1037/pspi0000136

Abstract: Existing trust research has disproportionately focused on what makes people more or less trusting, and has largely ignored the question of what makes people more or less trustworthy. In this investigation, we deepen our understanding of trustworthiness. Across six studies using economic games that measure trustworthy behavior and survey items that measure trustworthy intentions, we explore the personality traits that predict trustworthiness. We demonstrate that guilt-proneness predicts trustworthiness better than a variety of other personality measures, and we identify sense of interpersonal responsibility as the underlying mechanism by both measuring it and manipulating it directly. People who are high in guilt-proneness are more likely to be trustworthy than are individuals who are low in guilt-proneness, but they are not universally more generous. We demonstrate that people high in guilt-proneness are more likely to behave in interpersonally sensitive ways when they are more responsible for others’ outcomes. We also explore potential interventions to increase trustworthiness. Our findings fill a significant gap in the trust literature by building a foundation for investigating trustworthiness, by identifying a trait predictor of trustworthy intentions and behavior, and by providing practical advice for deciding in whom we should place our trust.

Neuroscientists uncover sensory switches controlling infanticide and parental behaviour in mice

Multisensory Logic of Infant-Directed Aggression by Males. Yoh Isogai et al. Cell, Volume 175, issue 7, p1827-1841.e17, December 13, 2018.

    •    Reconstituted pup shape and chemosignals trigger aggression by virgin males
    •    Repertoire of seven VNO receptors activated by pups is also stimulated by adult cues
    •    Deletion of receptors to salivary protein and hemoglobin shows role in pup attack
    •    Complex recognition involves pup’s shape and chemosignals from infants and parents

Summary: Newborn mice emit signals that promote parenting from mothers and fathers but trigger aggressive responses from virgin males. Although pup-directed attacks by males require vomeronasal function, the specific infant cues that elicit this behavior are unknown. We developed a behavioral paradigm based on reconstituted pup cues and showed that discrete infant morphological features combined with salivary chemosignals elicit robust male aggression. Seven vomeronasal receptors were identified based on infant-mediated activity, and the involvement of two receptors, Vmn2r65 and Vmn2r88, in infant-directed aggression was demonstrated by genetic deletion. Using the activation of these receptors as readouts for biochemical fractionation, we isolated two pheromonal compounds, the submandibular gland protein C and hemoglobins. Unexpectedly, none of the identified vomeronasal receptors and associated cues were specific to pups. Thus, infant-mediated aggression by virgin males relies on the recognition of pup’s physical traits in addition to parental and infant chemical cues.

Neuroscientists uncover sensory switches controlling infanticide and parental behaviour in mice

Both conservatives & liberals resist & accept societal changes, depending on the extent to which they approve or disapprove of the status quo on a given issue; we challenge assumptions on general, context‐independent psychological differences underlying ideologies

Liberalism and Conservatism, for a Change! Rethinking the Association Between Political Orientation and Relation to Societal Change. Jutta Proch, Julia Elad‐Strenger, Thomas Kessler. Political Psychology,

Abstract: According to common wisdom, which is supported by extant psychological theorizing, a core feature of political conservatism (vs. liberalism) is the resistance to (vs. acceptance of) societal change. We propose that an empirical examination of the actual difference in political liberals’ and conservatives’ attitudes toward change across different sociopolitical issues may call into question this assumed association between political orientation and relation to change. We examined this proposition in four studies conducted in Germany. In Study 1, we assessed lay people's intuitions about liberals’ and conservatives’ attitudes toward change. Results of this study concur with theoretical assumptions that liberals accept and conservatives resist change. In Study 2a, Study 2b, and Study 3, self‐identified liberals and conservatives were asked whether they would resist or accept change on various sociopolitical issues. Results of these studies suggest that both conservatives and liberals resist and accept societal changes, depending on the extent to which they approve or disapprove of the status quo on a given sociopolitical issue. Overall, our findings provide no evidence for a one‐directional association between political orientation and the tendency to accept or resist change. These findings therefore challenge theoretical and lay assumptions regarding general, context‐independent psychological differences underlying political ideologies.

The most comprehensive genomic analysis of the human brain ever undertaken has revealed new insights into the changes it undergoes through development, how it varies among individuals, and the roots of neuropsychiatric illnesses

Integrative functional genomic analysis of human brain development and neuropsychiatric risks. Mingfeng Li and dozens of authors. Science Dec 14 2018:Vol. 362, Issue 6420, eaat7615. DOI: 10.1126/science.aat7615

INTRODUCTION: The brain is responsible for cognition, behavior, and much of what makes us uniquely human. The development of the brain is a highly complex process, and this process is reliant on precise regulation of molecular and cellular events grounded in the spatiotemporal regulation of the transcriptome. Disruption of this regulation can lead to neuropsychiatric disorders.

RATIONALE: The regulatory, epigenomic, and transcriptomic features of the human brain have not been comprehensively compiled across time, regions, or cell types. Understanding the etiology of neuropsychiatric disorders requires knowledge not just of endpoint differences between healthy and diseased brains but also of the developmental and cellular contexts in which these differences arise. Moreover, an emerging body of research indicates that many aspects of the development and physiology of the human brain are not well recapitulated in model organisms, and therefore it is necessary that neuropsychiatric disorders be understood in the broader context of the developing and adult human brain.

RESULTS: Here we describe the generation and analysis of a variety of genomic data modalities at the tissue and single-cell levels, including transcriptome, DNA methylation, and histone modifications across multiple brain regions ranging in age from embryonic development through adulthood. We observed a widespread transcriptomic transition beginning during late fetal development and consisting of sharply decreased regional differences. This reduction coincided with increases in the transcriptional signatures of mature neurons and the expression of genes associated with dendrite development, synapse development, and neuronal activity, all of which were temporally synchronous across neocortical areas, as well as myelination and oligodendrocytes, which were asynchronous. Moreover, genes including MEF2C, SATB2, and TCF4, with genetic associations to multiple brain-related traits and disorders, converged in a small number of modules exhibiting spatial or spatiotemporal specificity.

CONCLUSION: We generated and applied our dataset to document transcriptomic and epigenetic changes across human development and then related those changes to major neuropsychiatric disorders. These data allowed us to identify genes, cell types, gene coexpression modules, and spatiotemporal loci where disease risk might converge, demonstrating the utility of the dataset and providing new insights into human development and disease.

Press release: In the developing brain, scientists find roots of neuropsychiatric diseases. Bill Hathaway. Yale News, Dec 13 2018.

Men in egalitarian tribe hide who are the best hunters, who out of modesty also cooperate masking how successful they are; they all get the girls with equal probability

Foraging Performance, Prosociality, and Kin Presence Do Not Predict Lifetime Reproductive Success in Batek Hunter-Gatherers. Thomas S. Kraft et al. Human Nature,

Abstract: Identifying the determinants of reproductive success in small-scale societies is critical for understanding how natural selection has shaped human evolution and behavior. The available evidence suggests that status-accruing behaviors such as hunting and prosociality are pathways to reproductive success, but social egalitarianism may diminish this pathway. Here we introduce a mixed longitudinal/cross-sectional dataset based on 45 years of research with the Batek, a population of egalitarian rain forest hunter-gatherers in Peninsular Malaysia, and use it to test the effects of four predictors of lifetime reproductive success: (i) foraging return rate, (ii) sharing proclivity, (iii) cooperative foraging tendency, and (iv) kin presence. We found that none of these factors can explain variation in lifetime reproduction among males or females. We suggest that social egalitarianism, combined with strikingly low infant and juvenile mortality rates, can mediate the pathway between foraging, status-accruing behavior, and reproductive success. Our approach advocates for greater theoretical and empirical attention to quantitative social network measures, female foraging, and fitness outcomes.

Keywords: Hunter-gatherers Reproductive success Foraging Prosociality Sharing Cooperation

Although Batek took quiet satisfaction in their skills and accomplishments, there was a strong social convention against overt bragging or showing off. Modesty was a valued trait. Hunters with gamewould usually enter camp quietly and then hand the carcass to someone else to butcher and distribute. Gatherers with loads of tubers would distribute their surplus to other families without fanfare. Although Batek strongly guarded their personal autonomy, they also felt an obligation to cooperate with other camp and group members. Competition was suppressed, even in games adopted from outsiders, such as cards.