Do We Turn Against Each Other When Resources Are Limited?

What happens to us as a society when resources are limited? Do we turn on each other, Mad Max style? Do we behave like the children in William Golding's novel The Lord of the Flies and go very quickly from friends to mortal enemies? With climate change at our heels, which will significantly reduce the available resources, this is obviously a burning question.

A new study on the behavior of rhesus macaque monkeys seems to offer a glimmer of hope here. The study examined the effects of a major hurricane on a population of rhesus macaques on an island off the coast of Puerto Rico. The hurricane devastated most of the trees in the monkey's habitat, which meant less shadow, a crucial resource for this species of rhesus macaques. So, how did the monkeys react?

Surprisingly, they did not become more aggressive toward one another. In fact, they became less aggressive and more tolerant. Macaques are not very good at sharing any kind of resources—food, drink, shadow—even if they are plentiful. So one would expect even more conflicts between them as resources get scarcer. But the opposite happened: The social ties and the level of social tolerance had increased.

Humans Are Not Macaques

This is a fairly heartwarming story with maybe a heartwarming message for how humans would react to a similar kind of situation. The problem is that humans are not macaques. In fact, one of the most important steps in the course of human evolution was the radical reduction of in-group aggression. If you put 30 macaques (or even 30 chimpanzees) on a bus, they will literally kill each other. But we humans are pretty good at not doing so day in and day out.

So just because a crisis situation lowered the aggression level of macaques, it does not follow at all that human aggression levels would not increase in a similar situation—as human aggression levels are incredibly low in comparison to any of our nonhuman relatives. So, as heartwarming as the macaque findings are, the jury is still out about whether we humans would turn against each other in a similar situation.

Aggression and Human Evolution

There is one important aspect of this study, though, that is very much relevant to understanding human evolution. It is one of the grand questions of understanding hominoid evolution and why human aggression has decreased so rapidly and so radically—especially as it is this change that, in turn, made a number of uniquely human traits possible. It has been suggested that the aggression reduction may have had to do with the increased size of human groups. But the recent findings about macaques may point to a different explanation: If sudden environmental catastrophes, which limit available resources, do lower aggression levels, then—paradoxically—the path of human evolution may have been made possible by repeated exposure to environmental catastrophes.