My research examines the evolution of the human life course. This work has at various times focused on food sharing, fertility decisions, parental investment, sex roles, subsistence behavior, intelligence, and life span.

My empirical work draws on fieldwork with a number of populations including the Ache (Paraguay), Mashco-Piro (Peru), Yora/Yaminahua (Peru), Machiguenga (Peru), and Xhosa (South Africa). My past work on fertility and parental investment has also drawn on a data collected from men living in Albuquerque, New Mexico. I currently direct the Tsimane Health and Life History Project with Michael Gurven (UC Santa Barbara).