South African monkeys switched foods purely because of peer pressure, suggest the results of a study in Thursday's journal Science.

"We're not as unique as we would like to think," said lead author Erica van de Waal, of the University of St. Andrews in Scotland. "We can find many of the roots of our behaviors in animals."

For her study, 109 vervet monkeys living in groups in the wild were given a choice of food tinted pink or blue by the researchers. One color for each group was tainted with aloe to give it a harmless yucky flavor. After a few meals, the food was no longer tainted, but the monkeys still wouldn't eat the color they figured was bad.

But that changed when some of them tried to fit in with a new group of monkeys. Blue-food eaters instantly switch when they moved to an area full of pink-food eaters, even though they shunned pink food before. Pink eaters also changed when they moved to a blue-food area.

The social pressure may be like "teenagers with a desperate need to be just like the other guys," said co-author Andrew Whiten, also of St. Andrews. Or it could be that the monkeys are learning to adapt to local custom — think restaurant reviews or the old saying "when in Rome, do as the Romans do," he said.