Robert D. Drennan pursues comparative analysis aimed at delineating patterns of variation in the developmental trajectories of early complex societies worldwide. He has carried out archaeological field research with a focus on regional settlement demography, communities, and households in Mesoamerica, northern South America, and northeastern China. He is Distinguished Professor of Anthropology and Director of the Center for Comparative Archaeology at the University of Pittsburgh, and a member of the U.S. National Academy of Sciences. C. Adam Berrey is an archaeological anthropologist specializing in the comparative study of early complex societies. His research focuses on the interplay between demographic, sociopolitical, and socioeconomic processes, particularly in the Isthmo-Colombian Area. He has carried out archaeological field research in central and eastern Panama, and is currently a Postdoctoral Researcher at the Universidad de los Andes in Bogota, Colombia. Christian E. Peterson identifies, analyzes, and compares patterns of variation in trajectories of complex society growth and decline so as to better understand the dynamics of social change. Topics emphasized in his research include regional settlement distribution, community patterning, and demography; household artifact assemblage analysis; public works investment; quantitative analysis, spatial analysis, and agent-based modeling. He conducts archaeological fieldwork in northeastern China. He is Professor of Anthropology at the University of Hawai'i at Manoa.