chimp-zoo
Humans and chimps have a lot in common. SIA KAMBOU/AFP/Getty Images

Self-control can be used as a measure of a person’s intelligence, and it turns out the same thing is true for chimpanzees.

Researchers have previously known the relationship between intelligence and self-control in humans but a new study extends the link to one of our closest relatives, the chimp. The paper, in the journal Current Biology, says that the animals who performed better on intelligence tests were also better at delaying gratification — they were able to turn down an immediate reward in exchange for a bigger one later on.

“The fact that such a relation exists in species other than humans likely reflects something foundational about the role of inhibitory, cognitive processes in general intelligence.,” the study says. “From an evolutionary perspective, the present data suggest that this relation has, at minimum, a shared origin within humans and apes. Future research with other species will be needed to illustrate whether other primates, and perhaps non-primate species, also show this relation.”

As Georgia State University points out, the test is related to a famous experiment called the “marshmallow test” in which children chose between taking a single marshmallow in front of them or waiting to have two marshmallows later on.

Part of the experiment is watching how the subjects react as they are attempting to wait for the larger reward, including seeing which emotions they display during that time.

With the chimps, just like the human children from the original test decades ago, the ones who performed best on tests of general intelligence were also the best at delaying their gratification and holding out for a bigger reward.

If this link were to be found in any animal other than humans, it’s not exactly surprising that it should be the chimpanzees. We share the overwhelming majority of our DNA with those fellow primates and previous experiments and studies over the years have found numerous other ways in which we are similar. That includes research that compared the lifespans of chimpanzees with those of hunter-gatherer humans and investigations into the social traditions of chimpanzees, which at times mirror our own.