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.

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.

This study proposes ways in which the environment may affect behavioral and psychocultural processes. Results provide moderate support for a relationship between climate and emotional expressiveness.

In this book, the author conducts a cross-cultural analysis of the complexities of different types of food-getting technology. This book centers around the "technounit" which is a term the author coined meaning a discrete component of a tool, weapon, or other technology. The research in this book is chiefly concerned with measuring technological complexity by counting these technounits. Qualitative analyses and quantitative measurements are conducted for different types of food getting technology including tools, weapons, and facilities, both tended and untended. Additionally, this type of analysis is conducted for different types of exploitative networks in various climates. The author concludes that each type of technology (tools to weapons to facilities) is more complex than the last. Other findings of this analysis are as follows: hunters tend to have more complex technology than farmers, cultures in the desert and tropical climates have less complex technology than those in temperate and arctic climates, and intensive hunters tend to have more complex technology than intensive gatherers. The author also concludes with theoretical notes on human technological production and on the possibilities of this type of cross-cultural research.

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.

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 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.

Previous studies have yielded contradictory results on the relationship between population size and cultural evolution. Focusing on tool complexity these authors introduce the risk of resource failure as a possible confounding variable. They conclude that population does not predict tool kit complexity when controlling on other factors. There were significant correlations between tool kit complexity and some of the resource measures.

This article explores the relationship between sexual dimorphism of stature and variables of marriage, diet, subsistence and environment. Significant associations were found between security and plentifulness of food supply, protein availability, and sexual dimorphism of stature.

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.