If you’ve ever had trouble telling apart animal faces, it’s probably because you became attuned to recognizing human faces through a developmental process called perceptual narrowing. Behavioral ecologist Michael Sheehan of the University of California, Berkeley compares the process to infants learning a new language.

"You start out being able to learn any language possible, right? And over time you hear certain sounds and you kind of focus in on those sounds that make or you hear the most regularly. And then over time you sort of become specialized, you know, so to speak from learning one language. The same thing happens with faces so like human infants when they’re younger are actually better at sort of telling apart primate faces than adults are because of the fact that we become more specialized on looking at humans in particular."

Sheehan says perceptual narrowing also explains why people often think that individuals of other races look the same.

"We’re much better at telling apart individuals that look like the group of people we saw growing up than people that look a bit different. So even though every group of people is very diverse in their appearance, our brains just don’t process it in the same way."

Photo: © Dr. Chris Lalonde