Face recognition: We use different methods to identify strangers

ResearchBlogging.orgWhen 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?

i-b8fd1324cb0038a7ac548eb5c3fd5ae3-fletcher1.jpg

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:

i-8690a5999d1744dedaac0571cd0db290-fletcher2.gif

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

More like this

Humans are exceptionally good at recognizing faces they've seen before. It doesn't take much study to accurately recall whether or not you've seen a particular face. However, this pattern breaks down when faces come from unfamiliar races. A white person who lives primarily among other whites will…
Nalini Ambady has become famous for her research on "thin slicing," the idea that ordinary people can make accurate judgments about others amazingly quickly. We've discussed work from her lab showing that people can accurately predict teaching ability by watching just six seconds of video of a…
This past weekend, I went to two different holiday parties. While many of the people at the parties were friends, I was also introduced to a couple dozen new people -- out of town guests of the hosts, friends of friends, or people from our small town that I somehow had never met. If I run into one…
We can quickly spot a face staring at us in a crowd. We can do this much quicker, for example, than we can determine that no one is staring at us, as this movie demonstrates. A grid of 100 pictures of Greta will be flashed for about 1/3 of a second. Can you spot the photos where she's looking at…

I often don't recognize baseball players without their batting helmets or ballcaps on.

Recently I saw Iron Man but could not name the actor playing Obadiah Stane. The voice was familiar, but with the shaved head and the beard, I could not recognize Jeff Bridges.

Incidentally, Fey's ears (A) are distinctly different from Palin's (B).

I'm going to look silly if I'm wrong, but...

This poll doesn't really work, because photo B is a commonly used stock photo for Sarah Palin. Thus for a lot of people, they're not recognising that it's the same person - they're recognising that it's the very same photograph, which is much easier.

I'm going to look silly if I'm wrong, but...

This poll doesn't really work, because photo B is a commonly used stock photo for Sarah Palin. Thus for a lot of people, they're not recognising that it's the same person - they're recognising that it's the very same photograph, which is much easier.

Sorry, I'm too big of an SNL fan. I can easily tell them apart.

Alex: Actually I took both pictures from screen-shots of the debates (the real one, and the fake one on SNL). So neither is a stock photo.

That said, people are pretty good at recognizing Palin -- I think she's gotten enough press lately that people can easily recognize her. Has anyone seen a similar poll from back when Palin was first announced as a VP candidate?

Interesting as ever. Does the "zoom" of the photo matter? Even though they're both clearly viewable, B "feels" magnified a bit.

Alternatively, this points to a difference (that I felt like I relied on): B's lower jaw is fuller and rounder.

By rsaunders_37205 (not verified) on 07 Oct 2008 #permalink

#1 - it took me FOREVER to place Jeff Bridges... I went through half the movie before I turned to the person next to me and said "He's the Dude."

I find that I more often recognise a voice than a face on TV programs, which is odd because I am poor at taking in verbal information.

By Richard Simons (not verified) on 07 Oct 2008 #permalink

Since I only saw Tina Fey once on YouTube (when she played the part of Palin being interviewed by Couric), I had to go with my first impression of her. "She's prettier than Palin."

So, I chose B.

By Monimonika (not verified) on 07 Oct 2008 #permalink

Palin is the one with the distinctly vacuous look in her eyes.

Huh, her eyes are wider. Wonder if that makes her more adorable when cornered?

It's funny. The first time I saw Palin, I thought "She looks just like Tina Fey". A few weeks after that, there's no comparison. Tina Fey is beautiful and awesome. Palin... not so much.

I can recognize faces very well, however I often forget their names.
But I can better recognize people on how they move. They may be fatter, thinner or even changed their hair style, I can still recognize them on how they move. That's if they don't make the effort to change the way they move....

By Al Joevid Mirasol (not verified) on 07 Oct 2008 #permalink

I was sitting in a restaurant when a waitress came up and spoke to my colleague in the local language, that I do not understand. The waitress had recognised my colleague from 30 years earlier when she, the waitress, had baby-sat her as a 4-year-old. My colleague did not want to get into a discussion so denied it but the waitress was adamant. I was astounded when I was told what had taken place. How does anyone extrapolate from a young child to an adult with no obvious scars, disfigurements or other peculiarities? There was not even a strong family likeness to her parents.

By Richard Simons (not verified) on 07 Oct 2008 #permalink

I have incredible difficulty remembering faces and attaching the right names to them (and I'm a high school teacher. Sigh). Very often, I'm using hair and clothing cues, as well as position in the classroom to figure out which of my students is which. Fortunately for me, they quite often favour the same hairstyle or ballcap or something. A student I'd had for a couple of months bleached his hair, and it took me at least a few minutes to figure out who he was.

I would say that at the end of the year, I might manage to recognize and identify by name about half of my students if I saw them in an unfamiliar setting. For the others I would simply be able to say "that one was one of mine at some point".

Despite this, I also know that I'm much more a visual learner than any other way, so my issue seems to be strictly with faces. But I had no problem with Fey vs. Palin - probably because I've been overexposed to both over the past couple of months...

For me, the tip-off is Palin's Crazy Eyes.

I'm with you guys. Tina looks like a woman. Sarah looks like a zombie. Easy for me, and I'm British so I;ve had slightly less exposure to this woman than most of you, and none at all to Tina.

I cannot access te paper and I am not very familiar with the literature.
Has anyone checked whether the ethnic background of the test subjects and/or of the individuals depicted affects (1) recognition success and (2) recognition mode?

I am quite good with faces, but I find it consistently more difficult to recognize people of different ethnicity from mine (Caucasian)

I'm a brit, and I just thought the one on the left looked like an actress and the one on the right looked like a politician.

God only knows why that worked!

By Justin Rowles (not verified) on 07 Oct 2008 #permalink

I agree with #20, there's a cultural / ethnic element to this as well. Ask sub-saharan black Africans (in rural sub-saharan Africa) how they recognise people - its a very different feature set to how I recognise people (as a European caucasian). Or ask Chinese people how they measure a 'big' nose (depth of bridge for them, against width of fleshy part for me).

Surely therefore how well we are able to decode facial differences depends on the feature set that we 'normally' use - from which comes my suggestion that our recognition ability is framed and shaped by cultural / ethnicity / geography.

In case there is any question about this -- the answer is B. Clearly our readers are quite familiar with Ms. Palin and Ms. Fey, since they were amazingly accurate.

It might have been fun to just briefly flash the photos to see if there was a difference in the response.

Clearly our readers are quite familiar with Ms. Palin and Ms. Fey, since they were amazingly accurate.

I think that 'and' should be an 'or'.
Over here on the other side of the world, I had never seen Ms. Fey before. I have seen Ms. Palin's face in the newspapers of course, but not as much as I imagine most US-ians have.
Nonetheless, I had absolutely no hesitation in knowing with certainty that photo B was Ms. Palin, given the knowledge that only one of them really was her.

Any mention of the fact that prosopagnosia may be more common than previously thought? I'm surprised this hasn't come up more often in relation to eyewitness testimony relating to crime scenes (I've just seen Spike Lee's CLOCKERS again, the plot of which partly hinges on the facial recognition of the murderer).

By David Group (not verified) on 10 Oct 2008 #permalink

ok this isn't a very worthy comment because there must be thousands of these examples, but a really freaky hard-to-recognise actor is Mel Gibson in The Singing Detective

By snaxalotl (not verified) on 18 Oct 2008 #permalink