What's fair is fair, even to a monkey.

Do children learn morality from their parents and teachers, or is ethical behavior wired into their genes? Researchers at Emory University in Atlanta reported in September that capuchin monkeys, which are found in South America, display at least some sense of fairness, a key criterion for judging right from wrong. They trained the monkeys to trade pebbles for food. If a monkey saw a researcher giving her neighbor a grape in return for a pebble, but she herself received only a cucumber slice, she would signal displeasure by slamming down the pebble or refusing to eat the cucumber. The study suggests that monkeys have a sense of fair treatment and protest when their expectations are violated. The research is part of an effort by evolutionary biologists to prove a genetic basis for social behavior. If a sense of fairness exists in these monkeys, it probably developed early in primates, and the genes that promote it are likely present in people too.