A new study from UCLA researchers shows that the same mathematical models that describe how honeybees parsal their territory can be applied to gangs in Los Angeles. UCLA Newsroom interviewed lead author Jeffrey Brantingham for their article:
The way gangs break up their neighborhoods into unique territories is a lot like the way lions or honey bees break up space.
Further, the research demonstrates that the most dangerous place to be in a neighborhood packed with gangs is not deep within the territory of a specific gang, as one might suppose, but on the border between two rival gangs. In fact, the highest concentration of conflict occurs within less than two blocks of gang boundaries, the researchers discovered.
For the Criminology study, the team used Lotka–Volterra equations, which were designed to model the population dynamics of species competing for common resources. Since the 1930s, ecologists have used the equations to study the relationships between competing groups as diverse as bee colonies, troops of chimpanzees and prides of lions.
The equations are based on the principle that competition between groups determines where the boundaries between rivals form, and even a tiny amount of competition is enough to cause territories to form.
“What’s at work is a competitive balancing act where both gangs are trying to keep their rival as far away as possible,” Brantingham said.
The team looked at 13 gangs in the 6.5-square-mile area of Boyle Heights, a densely populated neighborhood on Los Angeles’ east side that is bounded by three freeways.
Using police records, the researchers then mapped 563 known gang crimes that occurred between 1999 and 2002 and have been attributed by police to at least one of the 13 gangs. To their surprise, most of the crimes fell on the borders that the model laid between gang territories. When crime locations did deviate from the borders, they did so in a configuration that was consistent with the model. For instance, the theory predicted that 58.8 percent of the crimes would occur within one-fifth of a mile of the border between two gangs — or just under two blocks — and 87.5 percent within two-fifths of a mile of the border — or just over three blocks. Overall, 99.8 percent of crimes could be expected to occur within one mile of the border, according to the theory.
In fact, the team found that 58.2 percent occurred within two blocks of the border and 83.1 percent within just over three blocks of the border; in total, 97.7 percent of the crimes took place within one mile of the border between gangs.
“You would think that we’re more complicated than other animals, so a model this simplistic shouldn’t work, but I was surprised that it fit as well as it did,” said co-author Martin B. Short, an assistant adjunct professor of mathematics at UCLA.