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.

One of the core psychological concepts of early childhood development is mother-infant attachment, an infant's drive to form a bond with one caretaker. John Bowlby identified this form of attachment as a fundamental evolved adaptation, with alternative forms of "insecure" attachment being deviations from the healthy developmental trajectory. In contrast, life-history theory emphasizes that alternative developmental trajectories can be thought of as adaptive strategies which match phenotypes to local conditions, and thus variation in infant attachment may be adaptive under different environmental conditions. Here the authors attempt to investigate whether variation in fertility and mortality rates are significant predictors of variation in infant attachment. However, they do not find enough variation to test their hypotheses since very few societies in the HRAF sample exhibit both low fertility and low mortality.