Researchers have found that monkeys can cooperate to solve a problem, demonstrating that coordination among groups does not necessarily require language. The scientists, who report their findings in the journal Current Biology, had a group of vervet monkeys play a game called the forbidden circle. A single low-ranking female was trained to open a container holding a large amount of food — but only when dominant monkeys in the group stayed outside an imaginary circle. For anyone to get any treats, they all had to coordinate their activity and show restraint.

It took 30 trials, but after learning the rules, all the monkeys followed them.

“Think of a human situation where a schoolteacher has a movie in mind if the class is quiet for an hour,” said Ronald Noë, a behavioral ecologist at the University of Strasbourg in France. “That is really hard for kids to understand — if one is noisy, the film is not shown.”

Yet, trial after trial, the monkeys patiently waited for one another to understand the game.

“They don’t react with aggression,” Dr. Noë said. “Everyone was keen on opening the box as fast as possible.”