Using paternal investment theory, the authors examine the relationship between paternal confidence and paternal investment in humans.

This study tests possible explanations for sexual dimorphism in human post-reproductive life-spans. The author focuses on explanations involving male paternal investment and finds that men in agricultural societies are more likely to invest in their offspring than men in hunter-gatherer societies.

This study retests data on sexual dimorphism of body size from the Wolfe and Gray (1982) study. The authors challenge previous explanations for variation in sexual dimorphism across cultures. They find that there is a consistent level of sexual dimorphism across cultures, regardless of cultural traits or average body size.

This study tests two models that predict the presence of dowry cross-culturally: the female competition model and the labor-value model. Results suggest that both models are predictive of dowry, however discriminant analysis finds the female competition model to be superior.