Kids perceive faces differently than we do. Specifically, they’re not great at recognizing a person if their appearance has changed. If you get a haircut, or grow a mustache, an adult who knows you will still spot you. A seven-year-old child, though, will probably be fooled by your “disguise.”
A study done at the Ruhr-Universität Bochum, in Germany, demonstrated that while kids between five and 10 years are pretty good at facial recognition, they’re still not as good as the grown-ups. The test put seven-year-olds inside an fMRI scanner, and showed them photographs of people. The pictures came in three sets of six. One set showed the same photo six times over. The second showed different people in each picture. The third set showed different pictures of the same person.
When adults see things over and over, habituation sets in, and our brains pay less and less attention. If we see the same photo six times in succession, our brains stop showing activity. When we see pictures of different people, the brain keeps lighting up, thanks to the new stimulus. But when we see different images of the same person, we only partly switch off.
Kids responded differently. Professor Sarah Weigelt and PhD student Marisa Nordt recorded the brain activity of the youngsters while they looked at the photos, focusing on the the fusiform face area in the temporal lobe, which specializes in facial recognition. They found that when kids look at the different pictures of the same person, they either think that they’re all different, or all the same.
“If children see different photos of one and the same person, they appear to say either, this is the same person, or these are two different people,” says Weigelt. “There’s nothing in between.”
This varies from child to child, suggesting that the age range studied by Weigelt and Nordt—five to 10 years old—is the time that kids are developing their facial recognition skills.
Another test also showed surprising results. Both adults and kids were shown pictures of people in profile. Kids are terrible at drawing people in profile, often putting the nose on the side, but still drawing two eyes. The expectation was that kids would develop the ability to read profiles as they got older, but the experiments showed that kids and adults are both bad at recognizing faces in profile.
Today’s thinking on how age relates to facial recognition is split into two camps. One thinks kids are done learning these skills by age five. The other says we keep improving until we reach the oddly-specific age of 32. Weigelt and Nordt’s results show that we’re definitely not done by five years old, but doesn’t help with the upper limit. The most interesting part, however, might be the binary aspect of the learning, the fact that kids either recognize all the photos as the same person, or none of them. As somebody who makes a good second income from tricking kids out of their pocket-money at family gatherings, I shall hold onto this fact. It’s a potential gold mine.
All Photos: © RUB, Damian Gorczany