Female-Female Competition Occurs Irrespective of Patrilocality

Repercussions of patrilocal residence on mothers' social support networks among Tsimane forager-farmers

While it is commonly thought that patrilocality is associated with worse outcomes for women and their children due to lower social support, few studies have examined whether the structure of female social networks covaries with post-marital residence. Here, we analyse scan sample data collected among Tsimane forager-farmers. We compare the social groups and activity partners of 181 women residing in the same community as their parents, their husband's parents, both or neither. Relative to women living closer to their in-laws, women living closer to their parents are less likely to be alone or solely in the company of their nuclear family (odds ratio (OR): 0.6, 95% CI: 0.3-0.9), and more likely to be observed with others when engaging in food processing and manufacturing of market or household goods, but not other activities. Women are slightly more likely to receive childcare support from outside the nuclear family when they live closer to their parents (OR = 1.8, 95% CI 0.8-3.9). Their social group size and their children's probability of receiving allocare decrease significantly with distance from their parents, but not their in-laws. Our findings highlight the importance of women's proximity to kin, but also indicate that patrilocality per se is not costly to Tsimane women. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.

Thriving together: the benefits of women's social ties for physical, psychological and relationship health

The relationship between social support and well-being is well established in social psychology, with evidence suggesting that these benefits are especially prominent among women. When faced with an environmental stressor, women are more likely to adopt a tend-and-befriend strategy rather than fight-or-flight. Furthermore, female friendships tend to be higher in self-disclosure and more frequently relied on for social support, which is associated with physical and psychological benefits. Women are also more effective at providing social support, further augmenting those benefits. We begin with an overview of the characteristics of women's social ties and how they can be especially useful in times of stress. We then transition to the benefits of female social networks even in the absence of negative events and incorporate research from health and social psychology to consider the positive implications of having strong social bonds and the negative implications of lacking such bonds. Additionally, we consider cross-cultural differences in tendencies to seek out social support and its subsequent benefits, as well as the need for more research with culturally diverse samples. It remains unclear the extent to which patterns of social support benefits for women vary cross-culturally. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.

Kin networks and opportunities for reproductive cooperation and conflict among hunter-gatherers

Little is known about the potential for reproductive conflict among hunter-gatherer populations, who are characterized by bilateral kinship ties, flexible residential mobility, and high offspring mortality. To assess the potential for reproductive conflict, we use longitudinal residence and reproductive history data for two bands of South American foragers. Using multilevel logistic regressions (N = 44 women, N = 712 person years), we examine how yearly measures of (i) camp composition, (ii) distribution of female kin and (iii) a woman's position in a female kinship network impact the likelihood of giving birth or experiencing a child's death. We compare conflict models to a demographic model that accounts for the proportion of women giving birth in a given year. Contrary to conflict models, results show that the odds of giving birth increase with the presence of highly related women. However, the odds of experiencing an offspring death are insensitive to the presence of coresident women. Network measures of closeness and centrality in the female kin network also show no significant effect on reproductive outcomes. Furthermore, chances of both births and deaths increase in years when proportionally more women are giving birth. We argue that demographic stochasticity relating to ecological conditions best predicts reproductive outcomes for women. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.