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To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to women's fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our species-including high levels of cooperation among males, high dependence on unequally held rival resources, complementarities between maternal and paternal investment, as well as social and legal institutions that enforce monogamous norms.

Converging lines of inquiry from across the social and biological sciences target the adult sex ratio (ASR; the proportion of males in the adult population) as a fundamental population-level determinant of behavior. The ASR, which indicates the relative number of potential mates to competitors in a population, frames the selective arena for competition, mate choice, and social interactions. Here we review a growing literature, focusing on methodological developments that sharpen knowledge of the demographic variables underlying ASR variation, experiments that enhance understanding of the consequences of ASR imbalance across societies, and phylogenetic analyses that provide novel insights into social evolution. We additionally highlight areas where research advances are expected to make accelerating contributions across the social sciences, evolutionary biology, and biodiversity conservation.

Human adaptation depends on the integration of slow life history, complex production skills, and extensive sociality. Refining and testing models of the evolution of human life history and cultural learning benefit from increasingly accurate measurement of knowledge, skills, and rates of production with age. We pursue this goal by inferring hunters' increases and declines of skill from approximately 23,000 hunting records generated by more than 1800 individuals at 40 locations. The data reveal an average age of peak productivity between 30 and 35 years of age, although high skill is maintained throughout much of adulthood. In addition, there is substantial variation both among individuals and sites. Within study sites, variation among individuals depends more on heterogeneity in rates of decline than in rates of increase. This analysis sharpens questions about the coevolution of human life history and cultural adaptation.

Persistent interest lies in gender inequality, especially with regard to the favouring of sons over daughters. Economists are concerned with how privilege is transmitted across generations, and anthropologists have long studied sex-biased inheritance norms. There has, however, been no focused cross-cultural investigation of how parent-offspring correlations in wealth vary by offspring sex. We estimate these correlations for 38 wealth measures, including somatic and relational wealth, from 15 populations ranging from hunter-gatherers to small-scale farmers. Although small sample sizes limit our statistical power, we find no evidence of ubiquitous male bias, at least as inferred from comparing parent-son and parent-daughter correlations. Rather we find wide variation in signatures of sex bias, with evidence of both son and daughter-biased transmission. Further, we introduce a model that helps pinpoint the conditions under which simple mid-point parent-offspring wealth correlations can reveal information about sex-biased parental investment. Our findings are relevant to the study of female-biased kinship by revealing just how little normative descriptors of kinship systems, such as patrilineal inheritance, capture intergenerational correlations in wealth, and how variable parent-son and parent-daughter correlations can be. This article is part of the theme issue The evolution of female-biased kinship in humans and other mammals.

Persistent interest lies in gender inequality, especially with regard to the favouring of sons over daughters. Economists are concerned with how privilege is transmitted across generations, and anthropologists have long studied sex-biased inheritance norms. There has, however, been no focused cross-cultural investigation of how parent-offspring correlations in wealth vary by offspring sex. We estimate these correlations for 38 wealth measures, including somatic and relational wealth, from 15 populations ranging from hunter-gatherers to small-scale farmers. Although small sample sizes limit our statistical power, we find no evidence of ubiquitous male bias, at least as inferred from comparing parent-son and parent-daughter correlations. Rather we find wide variation in signatures of sex bias, with evidence of both son and daughter-biased transmission. Further, we introduce a model that helps pinpoint the conditions under which simple mid-point parent-offspring wealth correlations can reveal information about sex-biased parental investment. Our findings are relevant to the study of female-biased kinship by revealing just how little normative descriptors of kinship systems, such as patrilineal inheritance, capture intergenerational correlations in wealth, and how variable parent-son and parent-daughter correlations can be. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.

Persistent interest lies in gender inequality, especially with regard to the favouring of sons over daughters. Economists are concerned with how privilege is transmitted across generations, and anthropologists have long studied sex-biased inheritance norms. There has, however, been no focused cross-cultural investigation of how parent-offspring correlations in wealth vary by offspring sex. We estimate these correlations for 38 wealth measures, including somatic and relational wealth, from 15 populations ranging from hunter-gatherers to small-scale farmers. Although small sample sizes limit our statistical power, we find no evidence of ubiquitous male bias, at least as inferred from comparing parent-son and parent-daughter correlations. Rather we find wide variation in signatures of sex bias, with evidence of both son and daughter-biased transmission. Further, we introduce a model that helps pinpoint the conditions under which simple mid-point parent-offspring wealth correlations can reveal information about sex-biased parental investment. Our findings are relevant to the study of female-biased kinship by revealing just how little normative descriptors of kinship systems, such as patrilineal inheritance, capture intergenerational correlations in wealth, and how variable parent-son and parent-daughter correlations can be. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.

This study examines how community perceptions, family‐related factors, and other psychosocial factors collectively shape young adults' intentions to stay in their nonmetropolitan communities for employment. Research on nonmetropolitan populations' intentions to stay has increasingly highlighted community factors, including perceptions of the community and social connections. However, perceptions of the community have often been studied linearly and researchers have overlooked the multidimensional nature of employment decisions. Thus, this study conducted a latent profile analysis of 513 nonmetropolitan young adults and identified four distinct profiles: positive perceptions of social and professional characteristics (38.79%), positive perceptions of overall community characteristics (35.28%), positive perceptions of long‐term life planning characteristics (15.79%), and negative perceptions of overall community characteristics (10.14%). Path analyses indicated that community perception profiles, characterized by more positive perceptions of family‐friendliness and enjoyment of an active social and professional life, are associated with greater intention to obtain or retain local employment in a nonmetropolitan community. The findings are mediated by the effects of embeddedness within a community and organization. Family support also plays a crucial role in job seekers' intentions to stay for employment. They also value their own perceptions of fewer barriers to staying in nonmetropolitan organizations. These findings provide policy implications for attracting and retaining young nonmetropolitan workers by aligning their aspirations with community, work, and social characteristics. [ABSTRACT FROM AUTHOR]

Objective: Parental time with children varies across cultures but has mostly been studied in a European context. In this paper we estimate whether the association of work and gender with parental allocation of time is different in South Korea and the United States. Background: We suggest that household level characteristics are associated with the time parents spend with their children, but that these associations are more gendered in South Korea than in the United States. Method: We used data from the 2003–2018 American Time Use Survey (n = 38,562) and 2004–2014 Korean Time Use Survey (n = 12,828). Using ordinary least squares, we estimated the association of the intersection of gender and work in predicting parental time with children. Results: Gender is an important factor in time allocation in South Korea, where education was positively associated and working hours were negatively associated with mothers', but not fathers', time spent with their children. In the United States, resources and work have a dominant role, as both parents tend to spend more time with their children if they have higher education and income and work fewer hours. Conclusion: In South Korea, a gendered regime is associated with the allocation of parental time only; mothers are influenced by their spouses' time allocation and resources. The United States follows a trade‐off regime, where resources are associated with time spent with children, whereas gender plays a smaller role in parental time allocation. Implications: Studying parental time allocation should account for the intertwined relationship of culture, resources, and gender. [ABSTRACT FROM AUTHOR]

With apologies, an incorrect author list was given in the article. An additional author, Chris von Rueden, (Jepson School of Leadership Studies, University of Richmond) also contributed to this work. Author Ryan Schacht's affiliation was out-of-date. His correct affiliation is: Department of Anthropology, East Carolina University.

Monogamy appears to have become the predominant human mating system with the emergence of highly unequal agricultural populations that replaced relatively egalitarian horticultural populations, challenging the conventional idea-based on the polygyny threshold model-that polygyny should be positively associated with wealth inequality. To address this polygyny paradox, we generalize the standard polygyny threshold model to a mutual mate choice model predicting the fraction of women married polygynously. We then demonstrate two conditions that are jointly sufficient to make monogamy the predominant marriage form, even in highly unequal societies. We assess if these conditions are satisfied using individual-level data from 29 human populations. Our analysis shows that with the shift to stratified agricultural economies: (i) the population frequency of relatively poor individuals increased, increasing wealth inequality, but decreasing the frequency of individuals with sufficient wealth to secure polygynous marriage, and (ii) diminishing marginal fitness returns to additional wives prevent extremely wealthy men from obtaining as many wives as their relative wealth would otherwise predict. These conditions jointly lead to a high population-level frequency of monogamy.

Objective: In this study, we examined the bidirectional association between fathers' work satisfaction and children's socioemotional skills from T1 (age 2) to T2 (age 4–5) and the mediating role of fathers' parenting. Background: For many parents, balancing family and work roles can be challenging, particularly for fathers who are now expected to be both "ideal workers" and "involved fathers." With multiple roles, fathers' experiences at work and in the family may have a mutual influence on each other. Method: This study used structural equation modeling on secondary data from the Early Childhood Longitudinal Study, Birth Cohort, to examine the associations and mediation mechanisms. Results: Results indicate a positive association between fathers' work satisfaction at T1 and children's socioemotional skills at T2 through fathers' higher self‐efficacy and lower parenting stress. Additionally, there was a positive association between children's socioemotional skills at T1 and fathers' work satisfaction at T2 through fathers' higher responsibility and lower parenting stress. Conclusion: Findings provide support for the spillover theory regarding the mutual influence of fathers' work‐related experiences and children's development. Implications: To help parents balance the demands of work and family, effective parenting education programs and supportive or person‐centered workplace policies are both essential. [ABSTRACT FROM AUTHOR]

Despite agreement that humans have evolved to be unusually fat primates, adipose patterning among hunter–gatherers has received little empirical consideration. Here we consider the development of adiposity among four contemporary groups of hunter–gatherers, the Aka, Savanna Pumé, Ju'/Hoansi and Agta using multi-level generalized additive mixed modelling to characterize the growth of tricep skinfolds from early childhood through adolescence. In contrast to references, hunter–gatherers show several consistent patterns: (i) children are lean with little fat accumulation; (ii) no adiposity rebound at 5 years is evident; (iii) girls on average have built 90% of their body size, and reach menarche when adiposity is at its maximum velocity; and (iv) a metabolic trade-off is evident in young, but not older children, such that both boys and girls prioritize skeletal growth during middle childhood, a trade-off that diminishes during adolescence when height velocity increases in pace with fat accumulation. Consistent results across hunter–gatherers living in diverse environments suggest that these patterns reflect a general forager pattern of development. The findings provide a valuable baseline for adipose development not apparent from reference populations. We emphasize both generalized trends among hunter–gatherers, and that inter-populational differences point to the plasticity with which humans organize growth and development. [ABSTRACT FROM AUTHOR]