Intent and mitigating circumstances play a central role in moral and legal assessments in large-scale industrialized societies. Al- though these features of moral assessment are widely assumed to be universal, to date, they have only been studied in a narrow range of societies. We show that there is substantial cross-cultural variation among eight traditional small-scale societies (ranging from hunter-gatherer to pastoralist to horticulturalist) and two Western societies (one urban, one rural) in the extent to which intent and mitigating circumstances influence (...) moral judgments. Although participants in all societies took such factors into account to some degree, they did so to very different extents, varying in both the types of considerations taken into account and the types of violations to which such considerations were applied. The particular patterns of assessment characteristic of large-scale industrialized societies may thus reflect relatively recently culturally evolved norms rather than inherent features of human moral judgment. (shrink)

Maternal grandmothers play a key role in allomaternal care, directly caring for and provisioning their grandchildren as well as helping their daughters with household chores and productive labor. Previous studies have investigated these contributions across a broad time period, from infancy through toddlerhood. Here, we extend and refine the grandmothering literature to investigate the perinatal period as a critical window for grandmaternal contributions. We propose that mother-daughter co-residence during this period affords targeted grandmaternal effort during a period of heightened vulnerability (...) and appreciable impact. We conducted two focus groups and 37 semi-structured interviews with Himba women. Interviews focused on experiences from their first and, if applicable, their most recent birth and included information on social support, domains of teaching and learning, and infant feeding practices. Our qualitative findings reveal three domains in which grandmothers contribute: learning to mother, breastfeeding support, and postnatal health and well-being. We show that informational, emotional, and instrumental support provided to new mothers and their neonates during the perinatal period can aid in the establishment of the mother-infant bond, buffer maternal energy balance, and improve nutritional outcomes for infants. These findings demonstrate that the role of grandmother can be crucial, even when alloparenting is common and breastfeeding is frequent and highly visible. Situated within the broader anthropological and clinical literature, these findings substantiate the claim that humans have evolved in an adaptive sociocultural perinatal complex in which grandmothers provide significant contributions to the health and well-being of their reproductive-age daughters and grandchildren. (shrink)

Across a wide variety of cultural settings, kin have been shown to play an important role in promoting women’s reproductive success. Patrilocal postmarital residence is a potential hindrance to maintaining these support networks, raising the question: how do women preserve and foster relationships with their natal kin when propinquity is disrupted? Using census and interview data from the Himba, a group of semi-nomadic African pastoralists, I first show that although women have reduced kin propinquity after marriage, more than half of (...) married women are visiting with their kin at a given time. Mobility recall data further show that married women travel more than unmarried women, and that women consistently return to stay with kin around the time of giving birth. Divorce and death of a spouse also trigger a return to living with kin, leading to a cumulative pattern of kin coresidence across the lifespan. These data suggest that patrilocality may be less of a constraint on female kin support than has been previously assumed. (shrink)

Humans are an exceptionally cooperative species, but there is substantial variation in the extent of cooperation across societies. Understanding the sources of this variability may provide insights about the forces that sustain cooperation. We examined the ontogeny of prosocial behavior by studying 326 children 3–14 y of age and 120 adults from six societies (age distributions varied across societies). These six societies span a wide range of extant human variation in culture, geography, and subsistence strategies, including foragers, herders, horticulturalists, and (...) urban dwellers across the Americas, Oceania, and Africa. When delivering benefits to others was personally costly, rates of prosocial behavior dropped across all six societies as children approached middle childhood and then rates of prosociality diverged as children tracked toward the behavior of adults in their own societies. When prosocial acts did not require personal sacrifice, prosocial responses increased steadily as children matured with little variation in behavior across societies. Our results are consistent with theories emphasizing the importance of acquired cultural norms in shaping costly forms of cooperation and creating cross-cultural diversity. (shrink)

The mother–adult daughter relationship has been highlighted in both the social sciences and the public health literature as an important facet of social support networks, particularly as they pertain to maternal and child health. Evolutionary anthropologists also have shown positive associations between support from maternal grandmothers and various outcomes related to reproductive success; however, many of these studies rely on proximity as a surrogate measure of support. Here I present data from the Puerto Rican Maternal and Infant Health Survey (PRMIHS) (...) comparing geographic proximity of mother and daughter with a self-reported measure of mother-to-daughter support. These two measures were used to predict infant health outcomes as well as various measures of instrumental and emotional aid provided during pregnancy and after birth. Primary support was shown to have a positive effect across the analyses, whereas geographic proximity was associated with an increased risk of infant mortality and low birth weight as well as reduced odds of receiving support. This paradox was then examined using a combination variable that teased out the interactions of maternal support and proximity. Women who were geographically close to their mothers but who did not consider them a primary source of support had increased odds of infant death and low birth weight, and were less likely to receive either tangible or intangible forms of aid, while women whose mothers were both close and primary showed uniformly positive outcomes. These results place the role of propinquity within the larger context of social support and highlight the need for more detailed studies of social support within evolutionary anthropology. (shrink)

Humans are obligate cooperative breeders, relying heavily on support from kin to raise children. To date, most studies of cooperative breeding have focused on help that supplements rather than replaces parental care. Here we propose that fosterage can act as a form of dispersed cooperative breeding, one that enhances women’s fitness by allowing them to disinvest in some children and reallocate effort to others. We test this hypothesis through a series of predictions about the costs and benefits of fosterage for (...) mothers, foster parents, and foster children using data from the Himba, a group of Namibian agro-pastoralists. We show that fostering out children enhances mothers’ fitness, and we provide evidence for a causal link from fosterage to enhanced fitness by showing that fosterage of early-born children is associated with greater maternal reproductive success. Foster parents minimize the costs of fosterage by skewing their care toward their postreproductive years, and by mainly fostering close kin. However, the system is associated with some detrimental effects on foster children, who are more likely to be stunted and underweight than their non-fostered counterparts. (shrink)

We argue that Benenson et al. need to consider not only sex differences in the effects of care on offspring survival but also in age-specific fertility when predicting how longevity affects fitness. We review evidence that staying alive has important effects on both women's and men's fitness, and encourage consideration of alternative explanations for observed sex differences in threat responses.