This work explores sources of conflict among forager-horticulturalist women in Amazonian Bolivia, and applies life history theory as a tool for understanding competitive and cooperative social networking behaviors among women. In this study, 121 Tsimane women and girls were interviewed regarding current and past disagreements with others in their community to identify categories of contested resources that instigate interpersonal conflicts, often resulting in incidences of social aggression. Analysis of frequency data on quarrels (N = 334) reveals that women target several diverse categories of resources, with social types appearing as frequently as food and mates. It was also found that the focus of women's competition changes throughout the life-course, consistent with the notion that current vs. future reproduction and quantity-quality trade-offs might have different influences on competition and social conflict over resources within women's social networks across different age groups. Aggr. Behav. 38:194–207, 2012. © 2012 Wiley Periodicals, Inc.