His research focuses on seal production and use in the Indus Civilization, combining experimental, ethnoarchaeological, and formal stylistic approaches to link variability in carving styles and techniques with the social, economic, and political structures in which it took place. More broadly, Gregg is interested in craft production and the organizational dynamics of the world's earliest urban societies. He received his Ph.D. from the Department of Anthropology at the University of Wisconsin, Madison.