Two chimps are better than one

Way back in kindergarten, most folks were taught the importance of cooperation. It turns out humans aren’t the only members of the animal kingdom to learn this lesson, however. A recent study by behavioral scientist Alicia Melis has shown that our hairy cousins can cooperate in a more sophisticated fashion than previously thought.

A pair of chimps holding hands. Graphic by Haylie Wise.
A pair of chimps holding hands. Graphic by Haylie Wise.

Melis, a professor of behavioral science at the University of Warwick in England, set out to discover whether chimps cooperate by chance when multiple individuals go after the same object, or if they could actually assume team roles and work together on purpose.

The study, published in the scientific journalĀ Biology Letters, supports the latter idea. Twelve chimps were paired off into teams of two, and each team was offered a box of grapes. Of course, scientists love to boobytrap things, and the boxes were rigged to only give out grapes if the chimps correctly used two specific tools in a specific fashion.

To further mess with the chimps’ heads, researchers gave both tools to one chimp in each pair, requiring that chimp to figure out the necessity of passing one of the tools to its partner. Ten out of the 12 chimps triumphed over this bit of sneakiness, and once the chimps had exchanged tools one time, they did it again almost every time the scientists put them to the test.

The box was placed in the middle of two adjoining rooms, one room containing each chimp. In order to get the grapes, the tool-wielding chimp had to pass the correct tool to its partner, while retaining the correct tool for its own end of the box. The chimps passed across the correct tool 75 percent of the time.

The results led Melis to suggest that chimps are limited in their cooperation more by a lack of motivation than by a lack of cognitive ability. Once the chimps realized they would personally profit from cooperating for the experiment, they did so very efficiently.

The fact that humans and chimpanzees both have the smarts to coordinate among themselves may indicate that such an ability originated in a common evolutionary ancestor, researchers said. Further studies with other primates, such as bonobos, could confirm this idea.

Now, if only researchers could confirm that legend about monkeys writing the works of Shakespeare, we’d be on the path to learning something about our history.