My perspective is that of human behavioral ecology, which attempts to explain variation in behavior as adaptive solutions to the competing life-history demands of growth, development, reproduction, parental care, and mate acquisition. Behavioral ecologists develop and test models to explain behavioral and cultural diversity. My research focuses on:

(1) biodemography of human lifespan and implications for understanding development, aging, intergenerational transfers and familial organization.

(2) social and economic behavior among foragers and forager-farmers. I am interested in understanding proximate and ultimate explanations for the diversity of pro-social behaviors we find in small-scale, traditional populations, as well as in large-scale modern societies.

These interests have culminated in the Tsimane Life History and Health Project, funded by NSF and NIH/NIA

I have conducted fieldwork with two South American lowland Indian populations, the Ache of Paraguay and the Tsimane of Bolivia.