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.

Using a sample of 313 societies classified within 24 language phyla, authors put forward a statistical model based on climate data [specifically focused on the 10°C (50°F) winter temperature isotherm] to explain why dispersion of preindustrial language phyla is remarkably homogeneous even despite heterogeneous geographical dispersion of sampled preindustrial cultural groups. They suggest that temperature has been a barrier to migration.

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.

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.

This study examines the relationship between infant stress and early menarche. Empirical analysis suggests that stress in infancy, such as mother-infant separation and head-shaping, are associated with early menarche.

This chapter examines how sorcery, sin, and the superego function in societies to uphold taboos and other forms of social control. The author also explores the child-rearing conditions that are necessary to produce and maintain these cultural mechanisms. Several hypotheses are tested and all are supported.

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.

Building on comparative study of the Mormons, Texans, and Zuni in the Rimrock area of Southwestern U.S., the authors cross-cultural test some hypotheses cross-culturally.

This paper hypothesizes that cross-cultural variation in rhythm is related to variation in infant carrying practices. Suggestions are made regarding the psychological origin of rhythm as well as the function and importance of music in human experience.

This article adds nuanced findings to the previous generalization that high sonority of the vowel explains its more frequent use in warmer climates. The authors find that “speakers in warm-climate languages make more use of the so-called “sonorant” consonants, that is, consonants with some of the qualities of vowels” (123).