This study asserts that premastication (the pre-chewing of food for infant feeding) has existed as a cross cultural human universal stemming from the post natal immaturity of infant development and their need to have nutritional supplements to breast milk before they develop the molars necessary to consume an adult diet. Hypotheses are informally tested by sampling 119 cultures from the eHRAf database and looking for frequency of premastication occurrence. About one-third with information on infant feeding mention pre-mastication.

Dietary variation has been implicated in population-level heath outcomes such as adult height and infant health. Here the author investigates these relationships in a sample of 118 nonindustrial societies, providing a comparative and quantitative assessment of nutrition and health cross-culturally.

This article examines reasons for the variation in sexual foreplay practices cross-culturally. Results suggest that exclusive mother-child sleeping arrangements is significantly associated with the presence of foreplay.

The Trivers-Willard hypothesis posits that concentrations of human milk immune factors vary with maternal condition (maternal diet diversity and body mass index) and the sex of the infant. Using linear mixed-effects models to analyze 358 milk samples from 10 international sites, the authors find minimal support for the Trivers-Willard hypothesis; only one immune factor, IgG, exhibited a significant relationship.

This article examines the effect of infant care on women's contribution to subsistence. Results suggest that women who begin supplementary feeding of their infants early participate in subsistence activities to a greater degree than women who begin supplementary feedings later.

This thesis uses a cross-cultural sample to examine the relationship between anemia and infant feeding practices. Examples from the ethnography are presented. Findings are largely descriptive on practice, but are largely inconclusive with regard to anemia.

This study examines the relationship between pairbonds and lactation, specifically the relationship between pairbond stability, alloparenting, and cross-cultural trends in breastfeeding. Findings show that both conjugal stability and availability of alloparental care are associated with age at weaning.

This study examines 12 matched pairs of closely related societies and suggests that there is a relationship between socialization pressure toward compliance (rather than assertion) and emphasis on food production. Results also indicate that stronger compliance training is associated with higher indulgence in infancy and lower frequency of drunkenness in adulthood.

The relationships of aggression and crime to variables of childhood experience, adult behavior, and social structure are cross-culturally analyzed.

This study tests predictions of homosexuality. Results suggest that homosexuality is significantly associated with father-son contact.