When Sarah Palin was introduced to the country, most Americans had never heard of her — but many people noticed that she looked very similar to the then-more-famous actor Tina Fey. Can you tell which is which?
Let’s make this a poll:
We’re amazingly good at recognizing the faces of friends and family members. We can even recognize people we know well by viewing point-light displays of them walking. But what about strangers? If we see the same person twice, do we remember them correctly? How accurate are we at determining whether a person matches the photo on their passport or driver’s license? Obviously this can be very important for everyone from law-enforcement officials to cashiers selling cigarettes.
Studies have found that we can easily recognize people we know well when they change things like their glasses or hairstyle, but that we’re easily fooled by a similar hairstyle on two completely different people. But there hasn’t been much examination of what specific facial features people look at when comparing two people.
A group led by Kingsley Fletcher showed pictures of similar-looking strangers to people, two at a time, and asked them to say whether the photos depicted the same person or two different people. The viewers were wearing an apparatus that recorded their eye movements. Half the time, they were only given two seconds to view the photos, and half the time, they could look at the pictures for up to six seconds (rarely did viewers wait that long before making their judgements). Some of the picture pairs had similar hairstyles, and some of them had different hairstyles, and some of the pairs depicted the same person at different times, while others showed two different people. So, for example, you might see the same person with two different hairstyles, or you might see two different people with the same hairstyle. Here are the results:
So they were more accurate identifying the same person when they had a similar hairstyle (or other external features like clothing and jewelry), and more accurate identifying different people when their hairstyles were different. But this relationship only held when viewers were limited to two seconds of viewing. Given the full six seconds, people were equally accurate regardless of hairstyle.
An analysis of the eye-tracking data found that viewers who spent more time looking at internal features — eyes, mouth, nose — were more accurate than those who spent less time looking at those features. But again, this only held true for the two-second viewing period. Given enough time to view the photos, it didn’t matter where the viewers looked; they were equally accurate regardless of what portions of the photos they looked at.
The authors say security personnel and others who need to check identification should be trained to look exclusively at internal features like the eyes, nose, and mouth, especially when they faced with a time pressure.
And when you need to figure out if you’re looking at Sarah Palin or Tina Fey, you’re better off considering Fey’s asymmetrical smile or Palin’s wider eyes than looking at their hairstyles or eyeglasses.
Kingsley I. Fletcher, Marcus A. Butavicius, Michael D. Lee (2008). Attention to internal face features in unfamiliar face matching British Journal of Psychology, 99 (3), 379-394 DOI: 10.1348/000712607X235872