Two eyes, aligned horizontally, above a nose, above a mouth. These are the basic elements of a face, as your brain knows quite well. Within about 200 milliseconds of seeing a picture, the brain can decide whether it’s a face or some other object. It can detect subtle differences between faces, too — walking around at my family reunion, for example, many faces look similar, and yet I can easily distinguish Sue from Ann from Pam.

Our fascination with faces exists, to some extent, on the day we’re born. Studies of newborn babies have shown that they prefer to look at face-like pictures. A 1999 study showed, for example, that babies prefer a crude drawing of a lightbulb “head”