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.

Pregnancy sickness is characterized by nausea, vomiting, and food aversions during pregnancy, particularly during the first trimester. Previous work has asserted an adaptationist explanation for this phenomenon: pregnancy sickness protects the embryo from the toxic compounds found in many foods via expulsion (i.e., vomiting) of potentially dangerous foods and by encouraging aversions to foods likely to harbor toxins or pathogens. The authors reexamine 27 small-scale societies previously investigated by Minturn and Weiher (1984) for evidence of pregnancy sickness and food aversions in light of the fetal protection hypotheses.

The author tests various hypotheses regarding cross-cultural occurrence of geophagy, the eating of earth. Nearly 500 years of references to geophagy were compiled into the Database on Human Geophagy, which was then used to examine biological justifications for this little-understood behavior.

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 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.

This study tests the common belief that hunter-gatherers suffer more famine than other subsistence types. Controlling for habitat quality, authors examine the relationship between famine and subsistence type and find that hunter-gatherers actually experience significantly less famine than other subsistence types.

This article focuses on the culture of honor hypothesis, which suggests the distinctive selective pressures of horticultural and pastoral subsistences on culture. The authors explore which cultural evolution model best explains the variations suggested by the culture of honor hypothesis: the memetic, evolutionary psychological, dual inheritance, or niche construction model. The authors use the eHRAF database to test these rival models and explore how human psychology has adapted to pastoral and horticultural environments. The results support that it is more common for pastoral societies to show a reactive psychological phenotype. After considering their analysis and the distinct cases, the authors conclude that the niche construction is the best model to explain their results. They also emphasize the importance of continuing empirical analyses to test these models.

Do tropical hunter-gatherers follow the diet known today as the Paleo diet? Using nutritional data on 11 tropical hunter-gatherer groups, this study asses dietary composition. The results show that there are high levels of variation in the distribution of protein, fat, and carbohydrates among the sample of 11 hunter-gatherer groups.

This study tests the weaning food availability hypothesis, that both the introduction of foods other than breastmilk and the cessation of breastfeeding will vary by society's subsistence type. This hypothesis has implications for demography, as accelerated weaning can lead to increases in both mothers' fertility (due to decreased birth intervals) and infant mortality (due to the presence of pathogens in new foods).

The authors discuss why paraphilias are associated nearly exclusively with males, and why paraphilic tendencies are rare in traditional societies. Authors propose new research using the Zeigarnik affect as a way of thinking about probably causes of human paraphilias.