Evolution and Human Behavior最新文献

Parental influence over mate choice and marriage is a norm across many cultures and throughout human history; however, more attention has been given to preferences of the mating individuals than to the preferences of parents selecting a son- or daughter-in-law. Using data collected in Nepal, a culture with a tradition of arranged marriages, we compare the preferences of unmarried adults and parents of unmarried adults using a budget allocation task in which respondents allocated two budgets (high and low) to design their ideal spouse or in-law from a set of 14 traits. To compare overall similarities and differences in allocations across all 14 traits, we calculated the Mahalanobis Distance for each dyad type (father-son, father-daughter, mother-son, and mother-daughter) for high and low budgets separately. Parents and offspring disagreed more in high budget allocations than in low budget allocations, indicating that they may agree more on the minimally necessary traits in a spouse/in-law. Parents and offspring showed the largest divergence in allocations over same caste/ethnicity (preferred more by parents) and physical attractiveness (preferred more by offspring), in line with previous comparisons of parent and offspring preferences. Differences in the preferences of parents and offspring were at least as large as differences in preferences between men and women in this sample, indicating that parent-offspring disagreement is substantial and should be given more consideration in the literature on mate choice. Additional research is needed to investigate how parents and offspring negotiate their preferences in arranged marriage contexts.

As most organisms, humans and other apes compete for access to fitness-determining resources and competition is expected to increase with the competitor-to-resource ratio. We use 23 years of behavioural data on five wild groups from the two gorilla species which live in different socioecological environments, to test if female gorillas compete simultaneously for food, mates and/or protectors. Females were more aggressive to each other in medium-sized groups (∩ − shaped relationship) and when the groups contained more females but fewer males (lower sex ratio). Contrarily, female-female aggression was not influenced by the operational sex ratio and female mating activity. Hence, our results support the competition for food and protectors hypotheses but cast doubt on the competition for mates hypothesis. Yet, despite female western gorillas (Gorilla gorilla gorilla) experiencing higher monopolization potential of food and a lower abundance of food and males, they did not exhibit higher aggression rates than female mountain gorillas (Gorilla beringei beringei). Altogether, these results suggest that female competition for males outside the mating context is not unique to humans and might have common evolutionary origins in humans and other apes.

People vent, as when airing grievances about one mutual friend to another. Contrary to a Freudian account, such social venting does not alleviate anger. So, what function might it serve? That people bestow more and more likely support on relatively better-liked friends—support which is associated with greater health, happiness, and economic mobility—highlights a largely overlooked challenge in social groups: competing within the group for certain group members' affections and support. Social venting might be one effective tool for meeting this challenge. We test this—and also compare venting's efficacy with other forms of communication, including a well-studied tactic of partner competition (competitor derogation). In six experiments with U.S. CloudResearch participants (N = 1723), venting causes listeners (people vented to) to prefer venters over targets (people vented about) and to preferentially benefit better-liked venters over targets in a modified Dictator Game. By obscuring the venters' intent to aggress against the target, venting might communicate target-harming information in a way that buffers venters from being perceived unfavorably. Effective venting might thus manipulate listeners' attitudes and behavior in venters' favor.

Witchcraft beliefs are historically and geographically widespread, but little is known about the cultural inheritance processes that may explain their variation between populations. A core component of witchcraft belief is that certain people (‘witches’) are thought to harm others using supernatural means. Various traits, which we refer to as the ‘witchcraft phenotype’ accompany these beliefs. Some can be classified as ‘symbolic culture’, including ideas about the typical behaviour of witches and concepts such as familiars (witches' magical helpers), and demographic traits such as the age and sex of those likely to be accused. We conducted an exploratory study of the cultural evolution of 31 witchcraft traits to examine their inferred ancestry and associations with historic population movements. We coded a dataset from ethnographic accounts of Bantu and Bantoid-speaking societies in sub-Saharan Africa (N = 84) and analysed it using phylogenetic comparative methods (PCMs). Our results estimate that while some traits, such as an ordeal to test for witchcraft, have deep history, others, such as accusations of children, may have evolved more recently, or are limited to specific clusters of societies. Demographic and symbolic cultural traits do not typically co-evolve. Our findings suggest traits have different transmission patterns, and these may result from benefits they provide or from universal psychological mechanisms that produce their recurrent evolution.

Children have evolved “psychological weapons” to endear them to adults, enhancing their chances of surviving. Earlier research has shown that, during early childhood, caregivers feel positively attracted by children's vocal and cognitive cues of immaturity, which in turn provide adults with information about children's attributes and needs. The purpose of this study was to disentangle which of these two cues (vocal or cognitive), if either, might be more relevant for adults in assessing children's attributes and needs. College students (n = 273) listened to four pairs of children reasoning either in a mature or an immature manner about two types of thinking, one we labeled supernatural that reflects “magical thinking” (e.g., “The sun's not out because it's mad”) and the other we labeled natural that reflects abilities such as estimating one's cognition abilities or inhibition (e.g., “I can remember all the words you showed me”). In one condition (Consistent), the immaturity/maturity of children's reasoning matched the immaturity/maturity of their voices, whereas in the other condition (Inconsistent) they did not. Results revealed that, regardless of the type of reasoning, children's vocal cues prevailed over cognitive cues for assessing attributes of positive affect and helplessness. Conversely, children's cognitive cues prevailed over vocal cues for assessing intelligence (but only for supernatural thinking), and negative affect (but only for natural thinking). The results reveal natural selection's use of different cues of immaturity to promote caregiving during early childhood and reflect the complexity of multimodal features when adults evaluate young children.

The costly signaling theory of religion states that costly religious behaviors, badges, and bans (“religious practice” for short) are signals of commitment to the ingroup and its moral code. Such signals are proposed to increase cooperation. Here we review the empirical literature, which suggests that religious actors are often perceived as especially trustworthy and may be more likely recipients of help and cooperation. The evidence does not present a clear picture regarding the actual trustworthiness nor prosocial tendencies of religious actors. Limited available evidence suggests that routine forms of religious behavior are associated with ingroup favoritism. High-cost, infrequent, highly social forms of religious practice are associated with an increase in religious identity, but also an expanded social identity and greater tolerance for outgroup members. Following the literature review, we provide a discussion of proposed future research directions pertaining to the costs and benefits of religious practice, moderators, secular versus religious practice, and mediation of the relationship between observed religious practice and perceptions of religious actors' trustworthiness.

While scholars largely agree men's infidelity evolved by increasing offspring quantity, the evolutionary drivers of women's infidelity remain debated. The “good genes” (dual mating strategy) hypothesis posits infidelity allows women to pair the preferred genes of an affair partner with the preferred investment of their primary partner (Gangstad & Thornhill, 1998). The mate-switching hypothesis instead argues infidelity helps women obtain a new mate without a period of deprivation (Buss et al., 2017). To test these hypotheses, we conducted a pre-registered survey of 254 individuals from 19 countries and 6 continents who were previously or currently engaged in infidelity. We measured individuals' perception of their primary partner and their affair partner across four domains: physical attractiveness, personal attractiveness, attractiveness as a co-parent, and overall desirability (mate value). We also asked participants to report their motivations for the affair. Consistent with a dual mating strategy, women experienced stronger physical attraction to their affair partners and stronger parental attraction to their primary partners. Contrary to the mate-switching hypothesis, women did not prefer their affair partners overall, parentally, or personally. There were no significant gender differences in these findings, suggesting strategic dualism in men as well. Our qualitative data revealed a more nuanced story at the individual level, with participants reporting motives consistent with a variety of evolutionarily coherent strategies. While our quantitative results speak to the relevance of the dual-mating hypothesis to understanding infidelity, our findings also suggest that seeking infidelity's primary explanation in either gender is, perhaps, too simple an approach to the issue.

What past selection pressures have shaped human traits and their variation and covariation across individuals? These are key questions in the evolutionary social sciences. Recent advances in the field of human genomics have yielded a wealth of evidence that sheds light on these questions, yet the findings and their implications seem to be little known in the evolutionary social sciences. In this paper I aim to bring together these findings while explaining the conceptual and technical background that is often assumed knowledge for reading the primary reports. First, I outline the genomics methodologies that have enabled the relevant findings, such as genomewide association studies and DNA-based heritability estimation. I describe how these methodologies reveal the genetic architecture of traits, and then how this information in turn enables inferences about past selection. The findings show pervasive evidence that the genetic architecture of complex traits has been shaped by negative (purifying) selection, implying that the extant genetic variation in the traits has been maintained by mutation-selection-drift balance. On the other hand, there is no evidence that balancing selection has substantively shaped complex traits, and strong evidence that it has not. Finally, I discuss the implications of these findings for issues such as the dimensional structure of personality variation and the plausibility of psychological life history theory.

This study responds to Martin Daly's critique of our 2022 study on the correlation between income inequality and homicide rates in Mexican municipalities. Our updated analysis incorporates both immediate and lagged effects of income inequality, revealing significant non-linear relationships between past inequality and current homicide rates. We find that higher levels of past inequality interact with present inequality to increase homicide rates, particularly among currently average and highly unequal municipalities –not so much in less unequal municipalities. These findings support Daly's argument that economic inequality's influence on violent behavior accumulates over time, highlighting the need for a time dimension in homicide rate models. Our study emphasizes the importance of considering historical economic conditions when addressing socio-economic determinants of homicide, aiming to contribute constructively to ongoing attempts to effectively reduce homicidal violence.

We examined how children reason about dominance and prestige in Colombia, Finland, and the USA, contexts that vary in terms of societal inequality and hierarchical organization. We tested 496 children aged 4–11 years old to determine whether they: i) recognized and discriminated between dominance and prestige, ii) preferred to learn from a dominant or prestigious character, iii) assigned leadership to a dominant or prestigious character, and iv) self-identified more with a dominant or subordinate character. Older children were more likely to recognize, prefer, learn from, and assign leadership to the prestigious character, and to identify with the subordinate. There were no cross-cultural differences in learning preferences, supporting evolutionary theories that posit a universal bias towards social learning from prestigious individuals. There was variation in leadership preferences; children were the most likely to assign leadership to a prestigious character in more egalitarian Finland, and least likely in more unequal Colombia. We argue that societal factors including levels of inequality and hierarchical social organization shape an underlying propensity for children to learn to reason about rank and to broadly favor prestige in leaders and models for learning from.