How does cognition evolve? Phylogenetic comparative psychology.

I have two broad research interests, sexual differentiation and social behavior, both focused on hyenas and primates. I am particularly interested in unusual species in which the females display a suite of masculinized characteristics, including male- like or exaggerated external genitalia and social dominance.
The study of naturally occurring hormones in such unique mammals can reveal general processes of hormonal activity, expressed in genital morphology, reproductive development, and social behavior. Taking a combined laboratory and field approach allows me to relate captive data to various facets of the animals' natural habitat, thereby enhancing the ecological validity of assay procedures and enriching interpretation in an evolutionary framework. The goal of comparative studies of hyenas and lemurs is to help elucidate the mechanisms of mammalian sexual differentiation.

My research program in social behavior focuses on social learning and group cohesion. Using naturalistic tasks that I present to captive animals in socially relevant contexts, I can investigate how social interaction modulates behavior, problem- solving, and cognitive performance. By studying and comparing models of carnivore and primate foraging, I can better understand how group-living animals modify their actions to meet environmental demands. A primary interest is determining whether similar factors, related to having a complex social organization, influence learning and performance across taxonomic groups. I am also interested in how animals learn rules of social conduct and maintain social cohesion, as evidenced by their patterns of behavioral developmental, the intricate balance between aggression and play, the expression of scent marking, and the social facilitation or inhibition of behavior.