Most children practice this mental trick: When asked to wait patiently for a promised treat–say, an hour of television–they occupy themselves with a toy or a book. Researchers have now shown that chimpanzees engage in similar self-distraction, a finding that further blurs the cognitive and behavioral boundary between humans and other primates.
The discovery comes from a study conducted at Georgia State University in Atlanta. Psychologists Theodore Evans and Michael Beran put each of four chimps in front of a container connected to a candy dispenser. The chimps could reach over and pick up the container to eat the accumulated candies at any time, but doing so stopped the dispenser from delivering any more. That allowed the chimps to delay the reward as long as they wanted–so that they could get more of it.