Some insight into why it's harder to recognize different-age faces

ResearchBlogging.orgLast year's movie Changeling tells the story, from the late 1920s, of a mother whose son is kidnapped. Then, six months later, the police say they've found the boy and return him to his mother, who immediately claims that the boy they returned was not her son. She's then coerced into taking this child in, and doctors are brought forward to convince her that this is really her son. People change, she is told, and she's has been through severe mental trauma. Surely the best medical minds in the country know better than a single mother.

The film ends up being a scathing indictment of the LAPD, but even more, the sad state of what passed for psychiatric care in that era. But it also brings up a very different question: what does it mean to be an "expert" at recognizing an individual? Does a mother have a special ability not shared by others? In another scene, the kidnapper's nephew is asked to identify pictures of the children he was forced to abduct. He recognized a photo of our heroine's son. Can we trust him?

Several studies have shown that people are better at recognizing others who look like themselves (same race, same age) compared to those who look different. The same-race effect has been studied more extensively (and we've discussed some of it here), but the same-age effect is quite strong too.

But what causes the effect? Are we better at recognizing faces we see more often, so since whites are less likely to encounter black people, they're simply not as good at recognizing black faces? Or do we have separate process for people who are in our group, versus outside it? Or are we better at recognizing the faces we care about more? This would explain one study, which found that while white South African university students were better at recognizing white faces than black faces, the reverse did not hold true for black students. Arguably, it's more important for black people to be able to identify white people, since whites are the dominant social group in that setting.

A recent study by Virginia Harrison and Graham J. Hole was able to address some of these questions. They showed faces of boys (age 8-11) and adult men to 66 university students. Half of these students were in a teacher-training program and had been working with kids this age for an average of more than a year. The other half had very limited contact with children.

Everyone saw 32 pictures of faces, 16 from each age group (either smiling or neutral), flashed for three seconds at a time. They were told to memorize the faces for a test. They were then distracted for three minutes, and tested on a new set of photos: 32 different people, plus 32 of the original group, but in a different pose (smiling or neutral). For each photo, the students had to say, as quickly and accurately as possible, whether they had seen that face before. Here are the results:


There was no difference in recognition of their own age group, but the teacher trainees were significantly better at recognizing kids' faces than the non-teachers. There were similar results for reaction time.

So age-related differences in face recognition appear NOT to be due to an in-group/out-group process. Teachers clearly aren't in the same group as their students, but teachers still recognize kids better than other adults their age. But it's possible that exposure to people in a different age group may be what causes the results we see (since teachers spend more time with kids). It's also possible that teachers do better because are just more motivated to recognize kids. This study can't tell which of these explanations is more important (or whether both contribute), but the researchers say they're working on a new study which can answer that question.

By the way, it almost goes without saying this work also suggests that a mother like the woman Angelina Jolie portrays in Changeling should be exceptionally well-qualified to recognize her own child, even months later. What better training at recognizing an individual could there be than rearing him or her from birth?

Harrison, V., & Hole, G. (2009). Evidence for a contact-based explanation of the own-age bias in face recognition Psychonomic Bulletin & Review, 16 (2), 264-269 DOI: 10.3758/PBR.16.2.264

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When my children were babies, I could identify most other children's ages between birth and age 2 to the nearest month. Now I am much vaguer, but I am still pretty good at identifying the ages of children + or - a year within my children's ages. That seems a similar phenomenon.

It could be that the motivation to recognize kids for pure identification is only part of the elements to a more correct identification. The other could be from pure observation of emotions, extra. Just as a mother is more likely to recognize her child's needs moreso than
another, the teacher trainees have been conditioned to pay closer attention to the children's emotional needs as well which is largely facial oriented. Thus the part at is in tune isn't purely identification but that which embodies the emotional element as well.

By jlorraine (not verified) on 27 Apr 2009 #permalink

There is a third related effect. At the age of about 40 I was carded by a vietnamese proprietor before he would sell me cigarettes. I commented on that, and he demonstrated to me that I was as incapable of guessing his age as he was of guessing mine. Not even my already graying beard was a clue for him.

I have also noted that my ability to guess same-race ages has changed over the years. Either today's 60 year olds really do look much younger than they used to, or my catching up to them is the cause, but I have always been aware of a cebtral spread around my own age that is more difficult than the extremes to guess.

re Changeling: I thought they could have made more of things like academic achievement and intelligence? The real son was obviously more intelligent than the substitute. Although it was seen through the eyes of young actors, so I cannot vouch for the accuracy of that observation of mine.

By GrayGaffer (not verified) on 27 Apr 2009 #permalink

As for me it indicates that our natural tendency is to distinguish our age and race better. But there is still question if it's natural because evolution prepared us or because we spend most time with certain group?. What is interesting we are still able to learn precise distinct other ages/races. And again - is it possible because of our motives or the amount of time we spend with definited groups? I look forward successive studies!

As a white American that has lived for extended periods of time in both Asia and Africa and who is married to an African man, I can say that recognition, to the extent that it is related to our ability to distinguish unique facial features, is a question of exposure.

When I first moved to Africa, "all Africans looked the same." I can now recognize which features are common to specific ethnic groups. West Africans, by the way, often say that all white people look the same. The South African study may not have found that due to the large presence of whites in South African media (I'm not familiar with the study).

Many Americans say that all asians look the same, while anyone who has spent time in the region (or who has many friends of asian decent in the US) can tell the difference between a Chinese person, a Japanese, a Korean, etc.

I have to agree with Jenn. I'm an American white male who lived in Asia for 5 years.. before living in the region, I couldn't tell faces apart. By the time I left, the reverse was true: I could easily no longer distinguish between white faces, and had a hard time remembering if I'd seen white faces before. (I also felt more uncomfortable in crowds of white people than of Asians people, and it seemed like the distribution of whites was uncomfortably high when I moved back to the states).

I believe exposure is the predominant driver of the phenomenon. Despite the diverse ethnic makeup of the US, our individual social circles are usually much more homogeneous. I would be interested to see a study which measures ability to accurately identify people of various ethnicities in relation to quantity and frequency of exposure to each group.

I agree with Jenn. I grew up in a small white community in the (NE USA). I was ultimately sent by a Federal Investigative Agency to an 80% black city in the south and handed 50 Mug shots, all of blacks. (African-Americans) With no experience in identifying racial characteristics, it took me about a year to learn them well, but after I did, whites (Caucasians) were more difficult to remember. After 12 years in the community, I wondered why it was difficult in the first place. Reading the posts on this matter, I now know why.