In the Economist,
MOST people, even the law-abiding, have ambiguous feelings towards the police. They are a salvation when it comes to protecting life, limb and property, but their efforts are, perhaps, slightly less welcome if your foot happens to slip momentarily on the accelerator. Few, however, would argue that human societies could dispense with their activities altogether. Even in villages, where everybody knows everybody else and social disapproval and the near-certainty of exposure are enough to discourage most criminal acts, the local bobby is a reassuring presence.
Most people, too, would assume such policing is uniquely human. But they would be wrong—at least if Jessica Flack, of the Santa Fe Institute in New Mexico, and her colleagues are correct. For Dr Flack thinks that monkey societies also have police. Moreover, removing those police makes such societies less happy places…
Dr Flack had discovered this behaviour in earlier research. Her latest work, just published in Nature, looked at how important policing is in maintaining harmony in the monkeys she studies, an Asian species called the pigtailed macaque. To do so, she went to the opposite end of the biological scale from that occupied by ethology (the science of animal behaviour) and borrowed a technique from genetics, called knockout analysis. In genetics, this involves “knocking out” a particular gene and seeing what effect its absence has on a cell’s biochemical network. In ethology, it involves removing particular animals from a group and seeing what effect that has on the group’s social network.