Research

For most of our evolutionary history humans lived in small-scale egalitarian societies of foragers integrated by face-to-face interactions.

The first large-scale complex societies with extensive division of labor, great differentials in wealth and power, elaborate governance structures, and cities appeared roughly 5,000 years ago. How this “major evolution transition” occurred is one of the biggest questions of social evolution, for which we still do not have a widely accepted answer.

This is not only a theoretical question. The ability of today’s societies to construct viable states and nurture productive economies varies enormously from nation to nation. Why do states sometimes fail to meet the basic needs of their populations? Why do economies decline, or fail to grow? In many ways differences between the present-day societies can be as large as differences between us today and our foraging ancestors 10,000 years ago.

My approach to answering these questions blends theory building with the analysis of data. I was trained as a mathematical biologist and now I use the same quantitative tools—mathematical and computer models, sophisticated statistical approaches to testing models and analyzing data—to answer questions about the evolution of societies, states, and civilizations.