Metacognition is the ability to be aware of your mental state — to think about thinking. Historically, psychologists have assumed it’s a pretty high-level process, which we can’t really do until age five or so. Researchers would test preschoolers on their ability to assess their own mental state, and find that the kids couldn’t.

But Simona Ghetti, assistant professor of psychology at UC Davis, recently wondered if the problem wasn’t simply in the experiments. She noticed that most tests of metacognition asked the participants to use words to describe their internal states — which, she theorized, is why little kids couldn’t do it very well. The barrier was linguistic, not cognitive. So she devised a metacognition test that asked preschoolers instead to point to pictures to illustrate their internal state. Ghetti would pose the kids a question, and ask them to point to a picture of a confident-looking child if they were sure of the answer, or a doubtful-looking child if they weren’t sure.

Bingo: The preschoolers apparently had no trouble identifying their internal state. As Ghetti put it:

The tests showed that young children are aware of their uncertainty in the moment. Even 3-year-olds pointed to the confident face when they correctly identified, for example, a drawing of a monkey that had some features removed to make it harder to recognize. They pointed to the doubtful face if they could not come up with a correct answer.

“Even 3-year-olds are more confident when they’re right than when they’re wrong,” Ghetti said.

This experiment, of course, comes on the interesting work of the neuroscientist Jonathan Crystal, who this spring argued that even rats demonstrate metacognition. Again, his trick was simply in devising a more-clever way of scrutinizing rat thought processes.

Granted, either or both of these studies could prove to be flawed or ultimately misleading. But in general, they demonstrate the part of the scientific process that I always really love — the ability of a new experimental protocol to unveil new information about the world. I write a lot about scientists, and I’ve grown to hugely admire the ones who are really good at devising elegant new experimental techniques.