Most big cities today are seen as centers of innovation and technology, gathering together wealth, culture, and creative ideas in order to keep pushing forward the cutting edge of human society. However, new research reveals that the way in which cities grow as their populations exponentially increase has followed the same pattern for centuries.

The study, conducted by anthropologist Scott Ortman and complex systems researcher Luis Bettencourt, analyzed archaeological data from thousands of ancient sites in Mexico. They found that even among the oldest ruins, social indicators such as public monuments and private houses were built in predictable ways.

Ortman, who is a professor at the University of Colorado, Boulder, and Bettencourt, who works at the Santa Fe Institute in New Mexico, based their research on the principle of “urban scaling.” Urban scaling is the theory of how cities impact social interactions among its residents, and how an increased population density can magnify certain social factors. For example, whenever a city’s population doubles, there is usually a 15 percent increase in the city’s “output per capita.” This increase can be positive, such as increased wages and GDP, or a negative increase in violent crime. Amazingly, the increase of 15 percent is fairly steady across the board in all relevant categories.

According to Ortman, he first realized that urban scaling could be applied to ancient cities as well as modern when he realized that the causes of the 15 percent phenomenon had nothing to do with modern social constructions such as capitalism or industrialization. Instead, he said, the “parameters are basic properties of human social networks on the ground. And so I thought, ‘Well, gosh, if that’s true, then these models should apply very broadly.’”

Ortman and Bettencourt based their research on an extensive and rare data set that was collected during an archaeological survey of the pre-Hispanic Basin of Mexico in the 1960s and 1970s. The survey covered 2,000 years of history and 1,550 square miles, from small towns to bustling metropolises such as Tenochtitlan, which had an estimated population of 200,000 in its heyday.

These ancient cities, the researchers found, grew in much the same way that modern cities do, by becoming primarily denser instead of wider as the population increased. Public monuments such as temples provided a good example of the cities’ socioeconomic productivity, while domestic houses portrayed the growth of private wealth.

The research, Ortman enthuses, “implies that some of the most robust patterns in modern urban systems derive from processes that have been part of human societies all along.” He added, “I just think that’s an amazing concept.”