Tuesday, January 24, 2023

The domains in which people most strongly chose mates who were similar to themselves were politics, religion, intelligence and substance use

A comprehensive meta-analysis of human assortative mating in 22 complex traits. Tanya B Horwitz, Matthew C Keller. bioRxiv, Mar 20 2022. https://doi.org/10.1101/2022.03.19.484997

Abstract: Assortative mating (AM) occurs when the correlation for a trait between mates is larger than would be expected by chance. AM can increase the genetic and environmental variation of traits, can increase the prevalence of disorders in a population, and can bias estimates in genetically informed designs. In this study, we conducted the largest set of meta-analyses on human AM published to date. Across 22 traits, meta-analyzed correlations ranged from r = .08 to r = .58, with social attitude, substance use, and cognitive traits showing the highest correlations and personality, disorder, and biometrical traits generally yielding smaller but still positive and nominally significant (p < .05) correlations. We observed high between-study heterogeneity for most traits, which could have been the result of phenotypic measurement differences between samples and/or differences in the degree of AM across time or cultures.

Humans show higher levels of fearfulness than other great apes, which has been adaptive for care-giving

The human fear paradox: Affective origins of cooperative care. Tobias Grossmann. Behavioral and Brain Sciences, April 18 2022. https://www.cambridge.org/core/journals/behavioral-and-brain-sciences/article/abs/human-fear-paradox-affective-origins-of-cooperative-care/B6DC0651D8B6EC81C43AF41BC22EDD15

Abstract: Already as infants humans are more fearful than our closest living primate relatives, the chimpanzees. Yet heightened fearfulness is mostly considered maladaptive, as it is thought to increase the risk of developing anxiety and depression. How can this human fear paradox be explained? The fearful ape hypothesis presented herein stipulates that, in the context of cooperative caregiving and provisioning unique to human great ape group life, heightened fearfulness was adaptive. This is because from early in ontogeny fearfulness expressed and perceived enhanced care-based responding and provisioning from, while concurrently increasing cooperation with, mothers and others. This explanation is based on a synthesis of existing research with human infants and children, demonstrating a link between fearfulness, greater sensitivity to and accuracy in detecting fear in others, and enhanced levels of cooperative behaviors. These insights critically advance current evolutionary theories of human cooperation by adding an early-developing affective component to the human cooperative makeup. Moreover, the current proposal has important cultural, societal and health implications, as it challenges the predominant view in WEIRD societies that commonly construe fearfulness as a maladaptive trait, potentially ignoring its evolutionary adaptive functions.