Societies tend to coalesce for pragmatic reasons—food production, shelter, companionship, and defense—evolving distinct cultures in the process. Whereas all societies eventually face the same basic challenges—resource depletion, crime, epidemics, and environmental despoliation, among them—the creative contributions of their diverse cultures, in the sciences and arts, often remain unique. This module (perhaps the most protean of them all) examines a wide range of topics, each a way of understanding how and why people form into groups, cities, and cultures, and the potential positive and negative consequences of such activities.