How many of these faces can you recognize?

Even though these are extremely famous individuals, it’s unlikely that you’ll be able to identify all four of them, because the pictures were taken early in life, before they became famous. But give it your best shot and try to name them in the comments. I’ll reveal the correct answers later today.
We know that there are some individuals who have great difficulty identifying even current photos of very famous people, and often can’t identify the faces of close friends or family members. This condition, called prosopagnosia, was once thought to be rare, but more recent estimates put its incidence at as high as 2.5 percent of the population. If this many people experience prosopagnosia, can we really call it a disorder? Perhaps some people are simply better than others at recognizing faces.
If this was the case, however, we would also expect that there are some people who are exceptionally good at recognizing faces, and for many years it seemed that no such people existed. But now a team of researchers led by Richard Russell has found several people they call “super-recognizers,” who have an amazing ability to recognize faces. One of these people, whose initials are C.S., says “it doesn’t matter how many years pass, if I’ve seen your face before I will be able to recall it.” In fact, she sometimes pretends she doesn’t remember a person, “because it seems like I stalk them, or that they mean more to me than they do when I recall that we saw each other once walking on campus four years ago in front of the quad!”
Russell’s team showed photos of 56 famous people before they were famous to these four individuals, and also to 25 people with normal face recognition ability. The super-recognizers identified more faces than any of the other respondents. But the “before they were famous” test has some problems. Test takers might have seen photos of the famous people early in life, or they might have never heard of the famous people in question.
So in a new experiment, volunteers (and the four super-recognizers) were trained to recognize a set of six non-famous faces. Then they shown different photos of the same individual, some of which were obscured with visual noise, along with distractor images of people they had never seen. For each of these images, they indicated whether they had seen the face before. As before, the super-recognizers performed significantly better. This graph shows the scores of each group on both tests:

The black squares show the scores of the super-recognizers and their initials; the other volunteers are represented by gray diamonds. The super-recognizers scored better than all the normal volunteers on both tests. Three of the super-recognizers took a third, even more difficult test and again fared better than everyone else.
But what is at the root of the super-recognizers’ special ability? One possibility is that rather than having superior memory, they are actually better at recognizing differences between faces. In a new experiment, volunteers and the super-recognizers completed a different task. They were shown eight sets of faces like this:

The six faces at the bottom are computer-altered versions of the face at the top. Each face has been changed a different amount by morphing the original with a different face. So in one case, the face might be 88 percent original, and 12 percent different, while in another only 40 percent of the original face is represented, while the morphed face accounts for 60 percent of its features. The task is to sort the faces in order of similarity to the original face. No memory is involved, just recognition. The task was completed both with the faces right-side-up and upside-down.
The test was also given to prosopagnosics, who show little difference in success rates: they perform equally badly whether the faces are upside-down or right-side-up. On this task, the super-recognizers were significantly better than both the normal volunteers and the prosopagnosics, as long as the faces were upright. When the faces were inverted, there was no significant difference between the super-recognizers and any other group, including prosopagnosics.
The researchers say these results suggest that there is a continuum of face-recognition ability. Prosopagnosia isn’t a “disorder,” it’s just one end of a spectrum of abilities capped off by the uncanny ability of super-recognizers to identify and categorize faces.
How common is super-recognition? This study can’t tell us, but given the fact that all the super-recognizers in this study say they often don’t fess up to their ability, It’s quite possible that a sizable number of people are highly adept at recognizing faces.
Are you a super-recognizer? If you can identify the four photos at the beginning of this post, you just might be. Post your guesses in the comments.
Russell, R., Duchaine, B., & Nakayama, K. (2009). Super-recognizers: People with extraordinary face recognition ability Psychonomic Bulletin & Review, 16 (2), 252-257 DOI: 10.3758/PBR.16.2.252