Monkeys can think about thinking too

Macaques have joined an exclusive group of animals that possess metacognition—the ability to think about their own thoughts.

Humans have long believed themselves to be masters of metacognitive processes—the ability to reflect on their own mental states. Recently, captive primates have shown otherwise. A new study of semi-wild rhesus macaques (the most famous species of macaque) provides important evidence that metacognition is not the preserve of humans, apes, or solely trained animals.

Alexandra Rosati (Harvard University) and Laurie Santos (Yale University) conducted an experiment with 120 rhesus macaques that involved searching for food either at the end of a single tube or in one of two V-shaped tubes. Half of the «subjects» were able to observe how the food was hidden; the other half were left in the dark. Each macaque participated only once.

The main question is what the screened monkeys do in the two-tube condition. The most effective strategy is to peer inside the gap where the tubes form a V, allowing them to check both tubes at once. However, choosing this approach requires metacognition. Specifically, the monkey must acknowledge that it doesn’t know where the food is hidden, then consider its options and choose a course of action.

Ultimately, 27 of the 30 monkeys began searching for food by peering inside the gap, compared to 13 uninitiated monkeys. When faced with two tubes concealing food, the monkeys mostly approached the central gap. They weighed their options and chose the most effective strategy. Moreover, the monkeys in the hidden, two-tube condition took a few seconds longer to begin searching, suggesting they were thinking before acting.

«They could have checked each tube individually by chance, but they didn’t,» says Rosati, suggesting metacognition was at work.

Michael Beran of Georgia State University, who studies metacognition in monkeys, hails the study as important new evidence: «By demonstrating that this was true in a group of semi-wild monkeys, we can have greater confidence that some animals engage in metacognitive processes.»

Original article at Scientific American.