If He Looks Stupid, He Probably Is

In a new study, both male and female subjects were able to accurately evaluate the intelligence of men simply by viewing photographs of their faces.

While many avow that you can't judge a book by its cover, researchers Karel Kleisner, Veronika Chvátalová, and Jaroslav Flegr, all based out of Charles University in the Czech Republic, showed that if that book is a man, you probably can.

For the study, which is published in PLoS ONE, 80 science students from Charles University -- 40 men and 40 women -- took an in-depth exam to gauge their IQ and were subsequently photographed with neutral face expressions. Another 160 participants assessed the photographs, judging the subjects' attractiveness and intelligence on a scale of 1 (the highest ranking) to 7 (lowest ranking).

When Kleisner, Chvátalová, and Jaroslav Flegr tore into the data, they returned an intriguing finding.

"Raters were able to estimate intelligence with an accuracy higher than chance from static facial photographs of men but not from photos of women."

Next, the team placed the photographed faces on computerized grids in an attempt to glean whether any facial features were associated with perceived intelligence.

"Faces that are perceived as highly intelligent are rather prolonged with a broader distance between the eyes, a larger nose, a slight upturn to the corners of the mouth, and a sharper, pointing, less rounded chin," the authors described. "By contrast, the perception of lower intelligence is associated with broader, more rounded faces with eyes closer to each other, a shorter nose, declining corners of the mouth, and a rounded and massive chin." (See the image above.)

But when the researchers checked to see if actual intelligence (indicated by measured IQ) was associated with specific facial features, they found no significant correlations.

"This means that our raters accurately assessed intelligence from faces of men based on visual cues that simply are not explicable from shape variability in men’s faces."

So why could both men and women accurately predict the intelligence of men, but not women, based on their looks?

One explanation the researchers put forth is that physical cues of intelligence may be sexually dimorphic. So while intelligence may be physically plastered on the faces of men, women may signal it in other ways.

While the study's principal finding merits a booze-bolstered conversation at a dinner party, it will need to be replicated among men of broader age and cultural backgrounds before we take it too seriously.

Source: Kleisner K, Chvátalová V, Flegr J (2014) Perceived Intelligence Is Associated with Measured Intelligence in Men but Not Women. PLoS ONE 9(3): e81237. doi:10.1371/journal.pone.0081237