Humans have been called “cooperative breeders” because mothers rely heavily on alloparental assistance, and the grandmother life stage has been interpreted as an adaptation for alloparenting. Many studies indicate that women invest preferentially in their daughters’ children, but little research has been conducted where patrilocal residence is normative. Bangladesh is such a place, but women nevertheless receive substantial alloparental investment from the matrilateral family, and child outcomes improve when maternal grandmothers are alloparents. To garner this support, women must maintain contact (...) with their natal families. Here, the visiting behavior of 151 interviewed mothers was analyzed. Despite the challenges of patrilocality and purdah, almost all respondents visited their own mothers, and mothers-in-law were visited far less. This contrast persists in analyses controlling for proximity, respondent age, postmarital residence, family income, and marital status. These results affirm the importance women place on matrilateral ties, even under a countervailing ideology. (shrink)

Previous research on warfare in a worldwide sample of societies by Ember and Ember (Journal of Conflict Resolution, 36, 242–262, 1992a) found a strong relationship between resource unpredictability (particularly food scarcity caused by natural disasters) in nonstate, nonpacified societies and overall warfare frequency. Focusing on eastern Africa, a region frequently plagued with subsistence uncertainty as well as violence, this paper explores the relationships between resource problems, including resource unpredictability, chronic scarcity, and warfare frequencies. It also examines whether resource scarcity predicts (...) more resource-taking in land, movable property, and people, as well as the commission of atrocities. Results support previous worldwide results regarding the relationship between resource unpredictability and warfare frequency. Results regarding resource-taking and atrocities are more nuanced and complex. In almost all findings, relationships are generally in opposite directions in nonstate and state societies. In post-hoc analyses, atrocities are significantly more likely to be committed in states than in nonstates. (shrink)

The papers in this special issue of Human Nature collectively consider societal and individual responses to a wide variety of environmental and social risks. The first paper considers societal level effects of pathogen risk on collectivism and conformity, avoidance of outsiders, and in-group loyalty in a worldwide cross-cultural sample. The second deals with societal-level effects of resource unpredictability on the nature and conduct of warfare in eastern Africa. The third deals with effects of volcanic eruptions and earthquakes and mediating factors (...) on individual perceptions of risk in Mexico and Ecuador. The final paper deals with effects of various types of father absence on women’s reproductive life histories in Bangladesh. (shrink)

The hypothesis that father absence during childhood, as well as other forms of childhood psychosocial stress, might influence the timing of sexual maturity and adult reproductive behaviors has been the focus of considerable research. However, the majority of studies that have examined this prediction have used samples of women of European descent living in industrialized, low-fertility nations. This paper tests the father-absence hypothesis using the Cape Area Panel Study (CAPS), which samples young adults in Cape Town, South Africa. The sample (...) contains multiple racial groups (blacks, coloureds [mixed race], and whites) and includes both males and females. Dependent variables include age at menarche, age at first sexual intercourse, and age at first pregnancy. Childhood stress is measured by father absence by age six (either never lived with father or lived with father some but not all years) and an index of childhood exposure to violence (measuring threatened or actual verbal or physical abuse). The hypothesis received no support for effect on age at menarche but was supported for age at first sex and first pregnancy. The model showed stronger support for coloureds and whites than blacks and had no predictive power at all for black males. (shrink)