Research

What exactly are emotions? And how can we quantify them. I am using several approaches to understand basic emotions, or affective states, in apes. One method is measuring breathing rate as an indicator of physiological arousal. But that doesn't distinguish positive or negative affective valence. I am using pose-estimation and machine learning to quantify subtly variation in facial and bodily expressions that may indicate differences in affect.

What holds a community together? Why, sometimes, do things fall apart? I am working with the Ngogo Chimpanzee Project and experts in social network analysis to examine how the largest community of chimpanzees ever known permanently split. What led to the breaking of social ties and the emergence of lethal aggression? How do community members go from "friend" to "foe"?

What is the physiology of friendship? When is an individual an adolescent and then an adult? To answer these questions, I collect urine from chimpanzees to determine levels of various metabolites indicative of growth, puberty, and social stress.

I build on research from earlier in my career, including comparative studies of lemur cognition and analyses of group size across primates, to frame how we ask and answer big questions in primatology and biological anthropology. Check out my talk, "Within-species Variation, Data Quality, and the Aims of Primatology," from Sept 22, 2020 for the Seminar on Frontiers in Social Evolution.