Can't Place the Face? Maybe It's Your Genes

(Feb. 23) -- A guest at a party taps your shoulder and says, "Remember me?" If you don't, just blame it on your genes.

New research shows that the ability to recognize faces is strongly genetic, meaning that your ability to identify a second cousin last encountered 20 years ago will depend heavily on whether your parents could do the same.

Skill at facial recognition is roughly 75 percent or more inherited, says Wellesley College vision scientist Jeremy Wilmer, the lead scientist behind the new research. That means the next time you draw a blank when someone swears to have met you before, "it's at least 75 percent your parents' genetic fault," Wilmer says.

The environment in which a person grew up does play a small role, but by far the largest influence is the genetic material handed down from parents to children, he says.

Scientists had suspected for years that face recognition might be genetic, because they've tracked down clusters of blood relatives who have trouble recognizing faces. One Las Vegas family, for example, included eight members over four generations, and they all struggled to identify other people by their faces, says Bradley Duchaine of University College London, another member of the research team.

But just because many members of one clan have the same disability doesn't necessarily mean it's in their DNA. It could be that they were all exposed to the same environmental factors in childhood.

So Wilmer and his team set out to study twins. They recruited identical twins, who share 100 percent of their genes, and nonidentical twins, who share only 50 percent of their genes. All the twins took a quiz in which they viewed six faces. Then they were shown a selection of faces and asked to pick those they'd seen before. (Take the test yourself.)

The resulting scores were all over the map. Some people did no better than if they had guessed wildly without even looking at the faces they were supposed to study. Others aced the test.

What intrigued the researchers was that for identical twins, in general, each racked up scores similar to the other twin's score. Fraternal twins were less likely to score close together. That translates to a strong genetic influence on face recognition.

The scientists double-checked their findings by having the twins take word memorization tests. They found that those who were whizzes at word memorization were not necessarily geniuses at face memorization -- meaning that the ability to store and recall faces is a unique and individual skill that has nothing to do with memory overall.

One scientist not affiliated with the research team describes its work as "beautiful." Neurobiologist Margaret Livingstone of Harvard University says that perhaps some genes make people want to look at faces, giving them the practice to shine at the task of recognizing a crooked eyebrow or a thick nose.

The new study was published in the most recent issue of the Proceedings of the National Academy of Sciences.