Abstract
The study proposes a model to explain how gift interactions produce changes in interpersonal relations and, subsequently, the structure of social organizations. The authors also suggest that gift interactions are a driving force in the transition of social organization (bands, tribes, and chiefdoms). According to the model, there is a positive correlation between the frequency of gift transactions and economic and social disparities. To verify their theoretical results, the authors compare this model to statistical analysis performed on 155 societies from the Standard Cross-Cultural Sample. The results support the model, as there are positive correlations between gift interactions and social/economic disparities. As additional results, the authors show that some cultural and environmental factors positively correlate to gift interactions, including population density, surplus production, and herding societies.