Exploring Cooperative Behaviors Among the Sena of Gorongosa National Park, Mozambique and the Dolgan/Nganasan of Ust'-Avam, Siberia

Why do humans cooperate? Mechanisms including inclusive fitness, reciprocal altruism, indirect reciprocity, and costly signaling provide explanations for human cooperation and partner choice. Using data from the Sena people of Gorongosa National Park, Mozambique and the Dolgan/Nganasan of Ust’-Avam Siberia, I examine several questions relating to cooperation. During a preliminary study, interview and observational data was collected that provide insight on the day-to-day activities of 33 households in Gorongosa National Park. Cooperative activities include cooperative socializing, play, cooperative breeding, and household labor. It was found that most daily activities observed were done solitarily and men were most likely to be participating in the cooperative activities. A social network analysis of cooperative hunts among the Dolgan and Nganasan allowed me to test the influence of relationship type, reciprocity, and centrality on partner choice and hunting returns. Hunters were more likely to choose kin and friends as partners, and these relationships had greater reciprocity than neighbors and acquaintances. Hunters with high outdegree centrality and betweenness centrality had greater production per capita hunting returns. These outcomes are consistent with inclusive fitness and reciprocal altruism, and the benefits associated with cooperation.