Humans get a bad press. Whether through organised war or individual acts of brutality, we seem to be responsible for an inordinate amount of death and destruction. So it might be surprising to realise that we are a relatively peaceful species. Not only that, according to psychologist Steven Pinker, human acts of violence have been steadily decreasing in frequency over millennia and continued to do so through the last century.
Chimpanzees, our closest relatives, exist in much more bloodthirsty societies than we do. Male chimpanzees have been estimated to have a one-in-three chance of dying a violent death over their lifespan. Not only that, gangs of chimpanzees frequently organise unprovoked massed raids on other chimp groups, which can lead to murder and cannibalism.
Great ape warfare requires carefully coordination within the attacking group, but commitment to one’s chimpanzee comrades can be highly fleeting. Alliances shift rapidly, according to the pay-offs for individuals. In fact, although chimpanzees cooperate in certain circumstances, their default behaviour is competitive. When two chimps can find food either by working together or separately, the psychologist Michael Tomasello has found that they naturally shun the opportunity to put their heads together in favour of competing.
This competitive stance contrasts with the human tendency for cooperation. Jeremy Goslin of Plymouth University says that comparing human and chimpanzee performance in simple pairwise games shows differences between our species that may underpin the relative peacefulness of human society.
Game theory, initially developed by the mathematician John von Neumann in the first half of the twentieth century, provides experimental psychologists with methods for examining collaboration and cooperation in the laboratory. “Even splitting a cake between two children has a game-theory solution to minimise envy and maximise satisfaction,” says Goslin. “How children, adults or chimpanzees deviate from optimal behaviour is highly informative about our natural social biases.”
A recent Scientific Reports paper shows that chimpanzees outperform humans in finding optimal strategies in simple competitive games. By contrast, a study of economic decision-making games published in Nature finds that people “who reach their decisions more quickly are more cooperative”, suggesting that our own first impulse is to work with our fellow humans, not compete.
Human civilisation is founded on cooperation. It is our ability to work together that has led to our physical domination of the planet. Very often this expansionist agenda has caused brutal and bloody conflict between societies. But Steven Pinker argues that our ever-expanding intellectual horizons and greater awareness of those with whom we share the planet means that our cooperative spirit embraces a much wider circle of humanity than it previously did. “While violence within society would appear to have declined as rationality has increased, the key to social cooperation lies with our irrational trust in our fellows,” says Jeremy Goslin. “Fortunately, until our close cousins can emulate our trust in others, they have little chance of replacing us with a ‘planet of the apes’”.
This post originated from a British Psychological Society Psychology in the Pub presentation by Jeremy Goslin, 19th June 2014.