Connecting with others makes people happier, but strangers in close proximity often ignore each other; we may avoid pleasant conversations with strangers because of miscalibrated concerns about starting them

Hello, stranger? Pleasant conversations are preceded by concerns about starting one. Juliana Schroeder, Donald Lyons, & Nicholas Epley. Accepted Journal of Experimental Psychology: General. Jun 2021. https://static1.squarespace.com/static/5c171ac1710699e060ed3d94/t/60c43987d485fc055656c1ca/1623472521485/Hello+Stranger+-+June+2021.pdf

Abstract: Connecting with others makes people happier, but strangers in close proximity often ignore each other. Prior research (Epley & Schroeder, 2014) suggested this social disconnection stems from people misunderstanding how pleasant it would be to talk with strangers. Extending these prior results, in a field experiment with London-area train commuters, those assigned to talk with a stranger reported having a significantly more positive experience, and learning significantly more, than those assigned to a solitude or control condition. Commuters also expected a more positive experience if they talked to a stranger than in the solitude or control conditions. A second experiment explored why commuters nevertheless avoid conversation even  when it is generally pleasant. Commuters predicted that trying to have a conversation would be less pleasant than actually having one because they anticipated that others would be uninterested in talking. These experiments clarify the precise aspects of social interaction that may be  misunderstood. People may avoid pleasant conversations with strangers because of miscalibrated  concerns about starting them.

Keywords: conversation; communication; social cognition; social motivation; wellbeing

Individuals rated their past relationship quality more negatively in retrospect than they had actually reported at the time

Peetz, Johanna, Aidan Smyth, and Adreinne Capaldi. 2021. “Ex-appraisal Bias: Negative Illusions in Appraising Relationship Quality Retrospectively.” PsyArXiv. June 18. doi:10.1177/0265407520907150

Abstract: Cognitive biases are prevalent within the context of romantic relationships. The present research investigated biases about relationships after they have ended. In a longitudinal design (N = 184), individuals reported relationship quality at two time points, as well as rated relationship quality retrospectively. Results supported an ex-appraisal bias: individuals rated their past relationship quality more negatively in retrospect than they had actually reported at the time. This bias was present across participants who stayed together and those who broke up but was three times larger for those whose relationships had ended. This bias may be a motivated cognition that helps individuals let go of their ex-partners after a breakup.

Those who believe crime is caused by a single gene believe that punishment should be weakened, are less supportive of rehabilitation efforts, and believe that offenders are less capable of redemption

Beyond a Crime Gene: Genetic Literacy and Correctional Orientation. Amanda Graham, J.C. Barnes, Hexuan Liu & Francis T. Cullen. American Journal of Criminal Justice, Jan 9 2021. https://link.springer.com/article/10.1007/s12103-020-09595-5

Abstract: Is there a “crime gene”? This question has been answered by the scientific community, and the response is a definitive “no.” Yet, it is unclear whether this information has been communicated to the general public. Furthermore, it is unclear whether people’s views about the genetics of crime influence their perceptions of the way offenders should be treated. This study uses attribution theory to understand how perceptions of the role of genetic factors in criminal behavior influence beliefs about the punishment, redeemability, and rehabilitation of offenders. Drawing on a national sample of White respondents (N = 392), this study finds that only a small proportion believe there is a single crime gene. Compared to other respondents, those who believe crime is caused by a single gene believe that punishment should be weakened, are less supportive of rehabilitation efforts, and believe that offenders are less capable of redemption. Implications of these findings are discussed.

Studies of females with congenital adrenal hyperplasia show how prenatal androgens affect behavior across the life span; large effects on interest and engagement in gendered activities, moderate effects on spatial abilities

Evidence and Implications From a Natural Experiment of Prenatal Androgen Effects on Gendered Behavior. Sheri A. Berenbaum, Adriene M. Beltz. Current Directions in Psychological Science, June 18, 2021. https://doi.org/10.1177/0963721421998341

Abstract: Sex and gender are key to people’s lives, and are the focus of scientific and popular interest and controversy. Sex-related psychological characteristics reflect more than socialization; they are influenced by sex hormones present during sensitive periods of development, particularly androgens that are present prenatally. Studies of females with congenital adrenal hyperplasia (CAH) show how prenatal androgens affect behavior across the life span; these hormones have large effects on interest and engagement in gendered activities, moderate effects on spatial abilities, and relatively small (or no) effects on gender identity, gender cognitions, and gendered peer involvement. In addition to showing the complexity of androgens’ effects on gendered behavior, studies of females with CAH provide an opportunity to test theories of gender development, gain insight into how nature and nurture work together, and examine mechanisms of development. The implications of this work have often been misunderstood, so we consider what it means—and does not mean—for biology to influence gender-related behavior.

Keywords: congenital adrenal hyperplasia, differences of sex development, gender development, gender identity, interests, natural experiments, peers, prenatal androgens, spatial abilities

New Research Claims Darwin Made an Error About Sexual Selection: Evolution of large males is associated with female-skewed adult sex ratios in amniotes

Evolution of large males is associated with female-skewed adult sex ratios in amniotes. András Liker, Veronika Bókony, Ivett Pipoly, Jean-Francois Lemaître, Jean-Michel Gaillard, Tamás Székely, Robert P. Freckleton. Evolution, May 22 2021. https://doi.org/10.1111/evo.14273

Abstract: Body size often differs between the sexes (leading to sexual size dimorphism, SSD), as a consequence of differential responses by males and females to selection pressures. Adult sex ratio (ASR, the proportion of males in the adult population) should influence SSD because ASR relates to both the number of competitors and available mates, which shape the intensity of mating competition and thereby promotes SSD evolution. However, whether ASR correlates with SSD variation among species has not been yet tested across a broad range of taxa. Using phylogenetic comparative analyses of 462 amniotes (i.e., reptiles, birds, and mammals), we fill this knowledge gap by showing that male bias in SSD increases with increasingly female-skewed ASRs in both mammals and birds. This relationship is not explained by the higher mortality of the larger sex because SSD is not associated with sex differences in either juvenile or adult mortality. Phylogenetic path analysis indicates that higher mortality in one sex leads to skewed ASR, which in turn may generate selection for SSD biased toward the rare sex. Taken together, our findings provide evidence that skewed ASRs in amniote populations can result in the rarer sex evolving large size to capitalize on enhanced mating opportunities.

Popular version Darwin Made an Error About Sexual Selection, New Research Reveals (sciencealert.com):

In a new study, my colleagues and I have confirmed a link between sexual selection and sex ratios, as Darwin suspected. But surprisingly, our findings suggest Darwin got things the wrong way round. We found that sexual selection is most pronounced not when potential mates are scarce, but when they're abundant – and this means looking again at the selection pressures at play in animal populations that feature uneven sex ratios."

[...]

This in no way invalidates Darwin's theories of natural selection and sexual selection. Our finding simply shows that a different mechanism to the one Darwin proposed is driving mating competition for animals living in sex-skewed populations.

Darwin's assumption was based on the idea that the most intense competition for mates should occur when there's a shortage of mating partners. But more recent theories suggest this logic may not be correct, and that sexual selection is actually a system in which the winner takes all.

That means that when there are many potential partners in the population, a top male – in our study, the largest and heaviest – enjoys a disproportionately high payout, fertilizing a large number of females at the expense of smaller males, who may not reproduce at all.

Autism diagnosis and symptoms were associated with greater brain maleness, but the effects appeared to be driven by differences in brain size; brain maleness may be due to he same factors that influence brain size

Testing the extreme male brain hypothesis: Is autism spectrum disorder associated with a more male-typical brain? Liza van Eijk, Brendan P. Zietsch. Autism Research, May 19 2021. https://doi.org/10.1002/aur.2537

Abstract: Autism spectrum disorder (ASD) is more common in males than females and has been linked to male-typical behavior. Accordingly, the “Extreme Male Brain” hypothesis suggests that ASD is associated with an exaggeratedly male-typical brain. To test this hypothesis, we derived a data-driven measure of individual differences along a male–female dimension based on sex differences in subcortical brain shape (i.e., brain maleness) by training our algorithm on two population samples (Queensland Twin IMaging study and Human Connectome Project; combined N = 2153). We then applied this algorithm to two clinical datasets (Autism Brain Imaging Data Exchange I and II; ASD N = 1060; neurotypical controls N = 1166) to obtain a brain maleness score for each individual, representing maleness of their brain on a male–female continuum. Consistent with the Extreme Male Brain hypothesis, we found a higher mean brain maleness score in the ASD group than in controls (d = 0.20 [0.12–0.29]), parallel to higher scores for control males than control females (d = 1.17 [1.05–1.29]). Further, brain maleness was positively associated with autistic symptoms. We tested the possibility this finding was driven by the ASD group's larger brains than controls (d = 0.17 [0.08–0.25]), given that males had larger brains than females (d = 0.96 [0.84–1.07]). Indeed, after adjusting for differences in brain size, the brain maleness difference between the ASD group and controls disappeared, and no association with autistic symptoms remained (after controlling for multiple comparisons), suggesting greater maleness of the autistic brain is driven by brain size. Brain maleness may be influenced by the same factors that influence brain size.

Lay Summary: A popular theory proposes that individuals with autistic spectrum disorder (ASD) have an “extreme male brain”, but this has not been subject to rigorous, direct tests. We developed a measure of individual differences along a male–female dimension and then derived this measure for 1060 individuals with ASD and 1166 neurotypical controls. Individuals with ASD had slightly more male-type brains. However, this difference is accounted for by males and individuals with ASD having relatively larger brains than females and controls, respectively.