This article tests the effect of environmental risk on parental investment, differentiating between maternal and paternal care. Results indicate that the saturation point of parental investment may be a function of environmental risk, as parental care experiences diminishing returns due to extrinsic risks.

This article tests a hypothesis regarding patterns of infant care in non-industrial societies. The authors find that a consistent pattern of infant care that emphasizes mother-infant contact exists among hunter-gatherers and other non-industrial societies. These infant care practices differ from those found in the United states that do not promote extensive infant-mother contact.

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 the presence of parent-infant body contact at birth in non-industrial societies and its effects on subsequent infant care. The results show that immediate parent-infant contact is not common among most societies and does not have a significant effect on the quality of infant care.

"The kin selection hypothesis posits that male androphilia evolved because androphilic males invest more in kin, thereby enhancing inclusive fitness." However, increased kin-directed altruism has only been seen in societies that exhibit transgendered male androphilia. To test the validity of the kin selection hypothesis for male androphilia, the authors examine the relationship between ancestral sociocultural conditions, access to kin, and societal reactions to homosexuality and the expression of male androphilia as transgendered or non-transgendered. They find that ancestral sociocultural conditions and bilateral and double descent systems were more common in transgendered than non-transgendered societies.

This article investigates paternal warmth, particularly its relationship with parental proximity (often used as its proxy) and maternal warmth. The author also investigates whether paternal warmth, paternal proximity, materal warmth, and socialization for aggression are good predictors of theft, homicide, and violence in offspring.

This study tests the validity of two previous diachronic studies examining the relationship between subsistence strategy and sexual dimorphism of stature with synchronic data. The authors find that neither hypothesis is valid.

This article explores the association between father-son relationships and bridewealth. Bridewealth becomes an instrument through which male parents impose their will on their male offspring. The hypotheses are supported by the results presented.

Previous studies have proposed a model of sexual selection that dictates that along with female and male choice, parental choice constitutes a significant sexual selection force in our species. This article aims at examining whether this model can also account for the mating patterns typical of agricultural and pastoral societies. The hypotheses are supported by the results presented.

This article tests hypotheses put forth by Murdock that female contribution to subsistence is associated with matrilocal residence.