Living in bigger, denser settlements allowed the inhabitants of ancient cities to be more productive, just as is true for modern urbanites, according to a new study by scientists at the University of Colorado Boulder and the Santa Fe Institute.
As modern cities grow, they obey certain rules. As the population increases, for example, the settled area becomes denser instead of sprawling outward. This allows people to live closer together, use infrastructure more intensively, interact more frequently, and as a result, produce more per person.
In a paper published last year, the research team—led by Scott Ortman, an assistant professor in CU-Boulder’s Department of Anthropology—found that this set of rules, known as urban scaling, appears to apply to ancient cities as well as modern ones. In that study, the researchers analyzed how artifacts were scattered and how houses were distributed to show that ancient cities also became denser as the population grew.
Now, the researchers have expanded this work to show that inhabitants of ancient settlements also became more productive as the size and density of their settlements grew, just as in modern cities. The new findings are being published today in the journal Science Advances.
“As the population of a community or settlement grows, the total production of that group grows even faster,” Ortman said. “Urban scaling theory makes the argument that the increase in productivity emerges from the increased rate of social interactions that occur. It’s cheaper for people to interact with each other because they are physically closer.”
For the study, Ortman and his colleagues, including SFI’s Luis Bettencourt, tabulated measurements of ancient settlements, temples and houses in the pre-Hispanic Basin of Mexico, what is now Mexico City and nearby regions. In the 1960s—before Mexico City’s population exploded—surveyors examined all its ancient settlements, spanning 2,000 years and four cultural eras in pre-contact Mesoamerica.
Using this survey data, the research team analyzed the dimensions of hundreds of temples and thousands of houses from about 4,000 settlements ranging from villages to imperial capitals to estimate populations and densities, construction rates of monuments, and household productivities.
Their results indicate that the more populous the settlement, the more productive it was, and the rate at which productivity increased was exactly the same as in modern cities.
“It was amazing and unbelievable,” says Ortman. “We’ve been raised on a steady diet telling us that, thanks to capitalism, industrialization, and democracy, the modern world is radically different from worlds of the past. What we found here is that the fundamental drivers of robust socioeconomic patterns in modern cities precede all that.”
Bettencourt adds: “Our results suggest that the general ingredients of productivity and population density in human societies run much deeper and have everything to do with the challenges and opportunities of organizing human social networks.”