Chimpanzees are smart, perhaps the smartest living things on Earth besides humans – that much is not in dispute. But exactly how smart are they, and how deep does their knowledge go? A new study by researchers at Georgia State University suggests that they may be more like us than anyone thought: They’re capable of metacognition, or the ability to think about and ponder one’s own knowledge.
An example of metacognition: A baseball player stands in the batter’s box, with the count full at three balls and two strikes. The pitcher delivers the next pitch – the batter, drawing on his knowledge and experience, recognizes the ball as being outside and flips his bat, reflexively starting off towards first base before the umpire signals the ball (and the resulting walk). Apparently, chimps are able to do more or less the exact same thing, indicating a more sophisticated level of cognitive function than scientists believed possible.
“The team’s approach was to think about what chimpanzees might naturally do in the wild that requires them to reflect on their knowledge and then act confidently or perhaps hesitate before moving,” said Dr. Michael Beran, associate director of the Language Research Center at Georgia State.
The study involved giving chimpanzees a series of computerized memory tests, designed to manipulate the strength of their memories based on the complexity of what they were asked to remember. After each test, correct answers were rewarded with food after a short delay, while incorrect answers weren’t rewarded at all. Crucially, the rewards appeared at a distance from the testing site, and disappeared quickly. This was the crux of the study – chimps were forced to either move to the food area based on the confidence of their answers, or wait for the computer to tell them and then rush to get the food before it disappeared if they were correct.
Confidence is, obviously, easier to measure in humans. We can vocalize it, and even quantify it with something like a 1-10 scale. Not only that, but we can belie our own lack of confidence if our body language doesn’t align with what we say. With chimps, it’s not so simple. That’s why the difference in testing and reward locations was crucial – they found that when chimps moved to the feeding area early, it was a signal of confidence in their answers. When the chimps gave incorrect answers, they didn’t move to the feeding area at all, indicating that they knew the answer was wrong when they submitted it.
“They did not have to do this,” said researcher Audrey Parrish. “The computer would always tell them whether they were right or wrong, but by moving early when they knew they were right, they got a head start toward retrieving their reward.”
This metacognition is useful to chimps outside of the laboratory. When swinging through branches high above the ground, they must be able to gauge whether or not they can make it to the next branch, for example. Though this is the first evidence that another species besides humans has this capability, that’s not to say that they’re able to apply it to situations as complex as we do. Still, the result is intriguing, and the researchers now want to test other primates (as well as non-primates) to see just how far down the family tree metacognition goes