Human Nature-An Interdisciplinary Biosocial Perspective最新文献

Human leadership and followership take many forms, shaped by the social, economic, political, and cultural contexts of our groups and societies. Underlying this complexity, we argue, are key elements of human social psychology regarding social comparison and the resolution of coordination and collective action problems. The Multi-Capital Leadership (MCL) theory posits that leader emergence and effectiveness depend on perceptions of individuals' abilities to provide benefits or impose costs in solving challenges of group living, through the deployment of different forms of capital: material, social, somatic (e.g., physical formidability, height, immune functionality), and neural (e.g., knowledge, intelligence, personality, supernatural abilities). We integrate this framework with a review of leadership across human societies, including in non-state and non-industrial contexts, and with novel comparative analyses of ethnographic data. This synthesis highlights how context-specific demands for coordination and collective action, and the accuracy of social comparison, shape the structure and dynamics of leadership and followership across cultures.

Height preferences when choosing a partner might reflect adaptive mating strategies, whereby tall men are deemed attractive to potential partners due to links with health and resource acquisition. However, height preferences are highly variable across populations and could reflect socially constructed gender norms. We examined the relationship between ideal partner height, the importance placed on partner height and endorsement of traditional gender norms. Participants (n = 242; 18-39yrs; UK-based, heterosexual) completed (i) five height-related questions (including own height, ideal partner height, maximum/minimum acceptable height), (ii) three gender norm questionnaires (sexist attitudes, feminist attitudes and alignment with masculine/feminine gender roles), and (iii) two open-ended questions about why height is important. Although ideal height ratio did not correlate with any gender role endorsement measures in either women or men, women who placed greater importance on height scored higher on sexism, lower on feminism and were less likely to find a short partner acceptable than women who placed less importance on partner height. Men who placed greater importance on height, and men who described themselves as more traditionally masculine, were less willing to accept a tall partner than men who scored lower on these measures. Women who rated height as important wanted to feel 'feminine/protected', whereas men wanted to feel 'masculine/dominant'. In this study, the 'male-taller' preference was exhibited, with women's preferences for tall partners being stronger than men's preferences for short partners. Height preferences were related to gender norm endorsement, suggesting that gene-culture co-evolutionary processes could potentially influence human height dimorphism.

Highly educated individuals have their first child at later ages compared to less-educated individuals, and parental investment is associated with the childbearing of adult children. However, no studies have explored the association between maternal and paternal investment and the timing of parenthood for adult daughters and sons, and whether this association varies by education level. Based on the parenthood penalty and life-history theory, it is hypothesized that parental investment decreases the age at first birth of highly educated adult children and increases the age at first birth of less educated and those currently enrolled in education, particularly between mothers and adult daughters. Event-history analyses were conducted on 4,111 participants and 894 first births from 13 waves of the longitudinal and population-based German Family Panel Analysis of Intimate Relationships and Family Dynamics Study (Pairfam). Results show that contact with mothers was associated with earlier parenthood in less-educated adult children and later parenthood in highly educated adult children. However, contact with fathers was associated with later parenthood in currently enrolled adult children and earlier parenthood in highly educated adult sons. Europe's fertility decline is largely due to delayed age at first birth and parental investment in adult children can contribute to and counteract this trend.

Previous research indicates that having children can negatively affect relationship satisfaction, yet it may also strengthen bonding between partners. Romantic love is hypothesized to serve as a commitment device contributing to marital satisfaction. Interestingly, the relationship between romantic love and the number of children is complex and has received limited empirical attention, especially in diverse cultural contexts. However, some evidence from traditional societies suggests a positive correlation. Guided by Sternberg's Triangular Theory of Love, we examined the relationship between the number of children and romantic love and its three components (passion, intimacy, commitment) across 25 populations. Based on prior research, we hypothesized that the number of children would be positively associated with passion and commitment but negatively associated with intimacy. Our global sample included 3,187 married or engaged individuals (55.9% women), aged 18-99 years (M = 38.69, SD = 10.55), from 25 countries. Contrary to our predictions, having children, but not the number of children, was negatively related to overall romantic love, intimacy, and passion, but unrelated to commitment. These findings suggest that parenthood may be linked to reduced romantic love, particularly in terms of intimacy and passion, across diverse cultural settings. This pattern may reflect challenges commonly associated with the transition to parenthood, including increased stress, fatigue, financial strain, and work-life conflict, which can diminish partners' sense of closeness and attraction. Overall, the results underscore the importance of supporting couples' romantic relationships during the parenting stage to help sustain emotional and physical connection under the demands of family life.

Bride kidnapping, where Women are abducted for marriage, persists in Kyrgyzstan despite being illegal. Although it is estimated that up to one-third of marriages in Kyrgyzstan result from abduction, the true prevalence of this practice is unknown. Estimates are based on self-reporting of a practice that has become illegal. Here we examine whether there are sex and intergenerational differences in this reporting, that reflect a changing legal and social environment that might influence the self-reporting of bride kidnapping marriage. Using data from 468 participants in two Kyrgyz villages collected through 2023, this study examines self-reporting discrepancies in kidnap marriages among married couples. Significant differences were found in how husbands and wives report their marriages: husbands often describe the marriages as consensual, while wives see them as non-consensual. These discrepancies show a convergence over time, with couples married more recently agreeing on the marriage type. Furthermore, fathers often reported their son's marriages as consensual, while the sons themselves reported them as non-consensual, highlighting a generational divide. Our findings suggest a normative transformation driven by cohort replacement, where evolving attitudes toward consent erode the cultural mechanisms sustaining bride kidnapping. This offers insight into the evolutionary dynamics of such gender-biased harmful practices, highlighting how legal reforms and societal pressures reshape perceptions over time.

Social dilemmas in the real world, such as pollution and the extraction of resources, often differ regarding the visibility of involved actors and their behavior. While publicly disclosing individual decisions in social dilemmas is known to increase cooperation, little is known about whether revealing individual identities specifically makes a difference. This study uses an artefactual public good field experiment conducted in rural Namibia with 144 villagers, who are randomly assigned to one of two experimental conditions: one in which group members' identities are not disclosed and one in which they are. Individual contributions to the public good remain private in both cases, so the only difference lies in whether participants can see who their group members are. In addition, the experiment's setting in village communities entails pre-existing social ties between participants, which likely amplify potential effects that revealing identities can have on cooperation and allow investigating the role of group composition, such as the share of friends and family members. Results, somewhat unexpectedly, show that contributions to the public good are significantly higher when group members cannot identify one another - a finding that can be explained by several, not necessarily mutually exclusive, mechanisms. Exploratory analyses further reveal that contributions in the identified condition are distinctly lower when group members are socially distant from each other. Although overall variability of contributions does not differ across the two experimental conditions, decisions are more homogenous within groups and more heterogeneous between groups when identities are disclosed.

The evolution of menopause, grandmothering and long lifespan represent key events in the evolution of human life history. Demographic studies have amply demonstated inclusive fitness benefits from grandmaternal care, but the hormonal bases of such care, and how it evolved in relation to other reproductive and demographic traits, have yet to be addressed in detail. We propose and evaluate a novel hypothesis for the coevolution and adaptive covariation of life history, physiology, and behavior among women in this context. The hypothesis centers on relatively low testosterone, which promotes: (1) earlier, higher fertility and fecundity, (2) earlier cessation of ovarian activity (leading to earlier grandmothering), and (3) enhanced alloparental care. The hypothesis can help to explain among-female variation in grandmaternal care, and potential trajectories for the concerted evolution of grandmothering, prolonged human lifespan, and associated life history traits. A suite of convergent evidence supports the hypothesis, and it makes new predictions that are straightforward to test.

Compared to other apes, humans show a distinctive capacity for the cultural learning and transmission of know-how: we extract know-how from other individuals and artifacts in ways that regularly give rise to forms of know-how that no single individual could realistically invent on their own. Such a capacity is plausibly foundational to humans' striking cultural prowess and hence all that goes with it (e.g., symbolic language, religion). In this article, we critically examine attempts to date the transformation of know-how copying in the hominin lineage through an estimation of the costs of stone toolmaking. More specifically, we take as our target the idea that the costs inherent in making early stone tools, that is, Oldowan and Early Acheulean tools, already likely reflect a meaingful upgrade in hominin know-how copying abilities. Our survey of potentially relevant costs of stone toolmaking is generous, covering: (i) the risks and dangers of toolmaking; (ii) the time, energy, and opportunity costs of toolmaking; and finally (iii) the material costs of toolmaking. Ultimately, we find that, based on current evidence pertaining to these costs, the case for inferring know-how copying abilities in Oldowan or even Early Acheulean stone toolmakers is weak. This skeptical conclusion, combined with independent evidence that the design of stone tools during this period likely remained within the range of what the relevant hominins could invent without know-how copying, points to a later date for the establishment of this crucial human skill.