This study examines the variability of siestas across cultures and considers how factors including climate, subsistence type, and disease susceptability relate to the presence or absence of siestas. The author finds a significant relationship between siestas and the presence of malaria.

This study examines the variability of siestas across cultures and considers how factors including climate, subsistence type, and disease susceptability relate to the presence or absence of siestas. The author finds a significant relationship between siestas and the presence of malaria.

This article focuses on the effect of environmental extremes and unpredictability on human behavior and reproductive strategies. Significant correlations were found between environmental extremes and unpredictability and several variables, including mobility, subsistence mode, and degree of polygyny.

This study explores ecological reasons that might explain why boys are mostly circumcised in tropical regions, particularly in Africa and the insular Pacific. The author postulates a long causal chain linking: 1) tropical climate to the growing of root and fruit crops; 2) the need to keep babies on mother's milk for as long as possible where the adult diet is lacking in protein; 3) a long post-partum sex taboo as a way to space births; 4) the practice of polygyny (and associated mother-child sleeping) in the face of a long sex taboo; 5) patrilocal residence; and 6) male initiation ceremonies which are believed to result from the combination of mother-child sleeping, the long poast-partum sex taboo and patrilocal residence.

This study examines husband-wife relationships, specifically rooming and sleeping arrangements, as they relate to variables such as infant care, subsistence, residence, and cultural complexity. Several hypotheses are tested and all are supported.

Researchers examine the body of literature on the practice of geophagy(the consumption of earth), shining a light on the harms, benefits, and proposed reasoning behind the practice cross-sectionally. In addition to this review of the literature, gaps in the literature and suggestions for future research are discussed.

This study explores ecological reasons that might explain why boys are mostly circumcised in tropical regions, particularly in Africa and the insular Pacific. The author postulates a long causal chain linking: 1) tropical climate to the growing of root and fruit crops; 2) the need to keep babies on mother's milk for as long as possible where the adult diet is lacking in protein; 3) a long post-partum sex taboo as a way to space births; 4) the practice of polygyny (and associated mother-child sleeping) in the face of a long sex taboo; 5) patrilocal residence; and 6) male initiation ceremonies which are believed to result from the combination of mother-child sleeping, the long poast-partum sex taboo and patrilocal residence.

This paper poses and tests relationships between local spatial variability of rainfall and property rights, as well as the degree of hierarchy, across 41 different tribal societies in Sudan. The authors find that there is a significant negative relationship between rainfall variability and degree of hierarchy. They also find that in the presence of local rainfall variability in Sudan, members of a tribe are more likely to establish common property institutions that allow access to all members.

The authors develop and empirically test a model in which exogamy is negatively predicted by community size, due to decreasing heterogeneity from endogenous marriages in small settlements, and positively predicted by disparity in productivity between communities which is 'smoothed out' by transfer of community members through exogamous marriages. Support for both predictions is found, which is used to argue that cultural traits like marriage customs are heavily influenced by population-environment relationships.

This chapter examines infant carrying practices across cultures. The author suggests that infant carrying practices are affected by both climate and history. Findings indicate regional patterns in infant carrying practices and in the borrowing of infant carrying practices within regions. Results support the hypothesis.