The ability of adults to digest lactose is common only in populations of European and circum-Mediterranean origin, a distribution thought to be a result of genetic adaptation to drinking milk from domestic livestock. Two additional hypotheses have been proposed to explain the distribution of high lactose digestion capacity: (1) supplemental calcium in high-latitude populations prone to vitamin D deficiency and (2) maintenance of water and electrolytes in the body in highly arid environments. However, these hypotheses are confounded by the shared ancestry of populations whose lactose digestion capability has been tested. Therefore, the authors test all three hypotheses using a phylogenetic comparative method for 62 cultures.

The author utilizes Beardsley et al.'s (1956) settlement pattern typology to develop a five-rank scale of cultural complexity. The scale was developed using 30 traits converted into categorical form. The scale is designed for use by archaeologists to infer or presume the existence of certain nonmaterial cultural traits in a given society.

Textor summarizes cross-cultural findings on pregnancy and childbirth pertaining to cultural, environmental, psychological, and social phenomena.

This article examines the relationship between sonority and climate. Results suggest that languages spoken in warmer climates have higher levels of sonority than languages spoken in colder climates.

A model for the development of counting systems is tested. The hypothesis presented predicts that unpredictable climate conditions result in inconsistent food supply which leads to the need for food storage and, thus, a system to account for the stored food. Results strongly support this hypothesis.

Prior research by Oswalt (1973, 1976) and Torrence (1983, 2001) has suggested that risk of resource failure is a significant predictor of toolkit complexity and diversity among hunter-gatherers. In this paper, the same relationship is tested among small-scale herding and farming groups. However, no significant correlation is discovered between any measure of resource risk and any measure of toolkit complexity. The researchers suggest that this absence may be the result of greater reliance on non-technological diversification methods among farmers (i.e. spatial diversification, mixed farming, intercropping), or of other unaccounted-for sources of risk (i.e. intergroup raiding and warfare).

This book investigates a broad hypothesis linking social solidarity and initiation ceremonies. The author proposes that “the degree of solidarity of a given social system determines the degree to which status transitions within it will be dramatized” (1). A variety of operational hypotheses are supported for both male and female initiation ceremonies.

This paper builds off previous research into the effect of population size and resource risk on complexity of subsistence technology by investigating the relationship between these independent variables and total number of material items and techniques used by various western North American hunter-gatherer groups. This tally of total technological complexity is found to be insignificantly related to population size or residential mobility; however, there is a significant correlation in the expected direction between technological complexity and one measure of resource risk (mean annual temperature during driest month). Tying this finding to previous analyses of subsistence technologies, the authors theorize that environmental risk is a pervasive driver of technological ingenuity and cultural evolution.

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.

Textor summarizes cross-cultural findings on the status of women in relation to cultural, environmental, psychological, and social phenomena.