“The face is an observable proxy for a wide range of factors, like your life history, your development factors, whether you’re healthy,” he said.

Faces contain a significant amount of information, and using large datasets of photos, sophisticated computer programs can uncover trends and learn how to distinguish key traits with a high rate of accuracy. With Kosinski’s “gaydar” AI, an algorithm used online dating photos to create a program that could correctly identify sexual orientation 91% of the time with men and 83% with women, just by reviewing a handful of photos.