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.

This article examines meat avoidance during pregnancy as an evolutionary adaptation. Data suggests that during pregnancy, meat avoidance is significantly more common cross-culturally than other types of food avoidance. The timing of meat avoidance, the presence of meat-borne pathogens, and sensory and ingestive changes in early pregnancy are also discussed.

This study investigates the conceptual frameworks involved in infanticide. Authors first examine data on infanticide and birth ceremonies, particularly the timing of these events and the infant and adult involved in each. Authors also examine reasons for performing infanticide, including illegitimacy, unwanted children, and excess children, finding them similar to reasons for performing abortion. Population control and implications for children's and women's status are also discussed.

Geophagy during pregnancy has been proposed to fulfill a number of adaptive functions, including relieving gastrointestinal distress, detoxification of the secondary compounds found in plant foods, and providing a supplementary source of minerals such as calcium. Using a sample of 60 African populations, the authors investigate geophagy during pregnancy in a cross-cultural perspective, emphasizing variation between dairying and non-dairying populations.

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.

This chapter attempts to explain why the number, importance, and duration of food and sex taboos during pregnancy vary cross-culturally. The author hypothesizes that differences in child socialization will be associated with differences in food taboos, and differences in sexual behavior and sanctions will be associated with sex taboos. Results support the hypotheses.

This study, primarily a review on the evolution of the human diet, also includes a small study on the distribution of meat-eating and its relationship with climate and cultural factors, namely subsistence type. The authors find that societies with subsistence strategies that prioritize fishing, hunting, or pastoralism also tend to consume more animal products, whereas those that focus on agriculture have more plant-based diets. The authors argue that these small-scale societies have a healthier approach to diet than industrialized societies regardless of their subsistence type or meat consumption.

This book examines population growth rate and its correlates by testing 274 hypotheses (derived from multiple theories) with an 18-society sample. Forty-one of these hypotheses were significant at the .05 level, leading the author to accept these relationships as reflective of the real world. The 274 hypotheses are grouped into 51 broader hypotheses, and marked by (*) where relationships are significant as designated by the author or by significance p < 0.05.

This paper is concerned with the variation in sexual behavior in humans. Authors test hypotheses regarding the relationships between sexual behaviors and beliefs concerning sex.

This study examines three theories of the origin of the plow. The author rejects the universalist approach on the basis that not all cultures that are aware of the plow adopt its use. Findings provide partial support for a theory focused on population density, particularly the importance of fallowing practices and labor productivity. The author’s own ecological approach, pointing to a culture’s staple food as a crucial variable, also receives empirical support.