Emergence and Aggregation


If we try to understand an individual event—such as a specific sermon, ritual performance, judicial decision, birth, business closing, residential move, or crime—we might turn to the cultural contexts and motivations of the actors, the structural factors that held influence, or the contingencies of historical chance. But when we try to understand aggregates of events, we encounter new possibilities and new challenges. Some—but not all—kinds of individual-level events aggregate up into surprising order. In these cases, order “emerges” at the aggregate level that cannot be predicted from the characteristics of the individual events or actors. How does this happen? And why?

In Spring 2014, Social Science Matrix sponsored a seminar on “Emergence and Aggregation” that drew upon multiple disciplinary perspectives to consider the challenge of “emergence,” also sometimes labeled as “the aggregation problem,” “complexity,” and  “the something from nothing problem.” Convened by Professor Jonathan Sheehan, from the UC Berkeley Department of History, and Professor Jenna Johnson-Hanks, from the Department of Demography and Sociology, the seminar brought together historians, sociologists/cultural demographers, and an economist-demographer to explore how scholars have thought about emergence over the past three centuries, as well as to examine the importance of emergence in the social sciences today.

Through readings and discussions the group contemplated the historical origins of the emergence problem. Readings included Sheehan’s recently completed book, Invisible Hands: Self-Organization in the Eighteenth Century, as well as Johnson-Hanks’ in-progress book about the problem of emergence in contemporary quantitative social science.