A research team from the University of York has determined that the average person is familiar with around 5,000 faces. This is the first time experts have managed to put a number on how many faces we recognize.
The researchers tested study participants on how many faces they could recall from their personal lives or from the media and television.
While humans typically exist in small groups of around one hundred individuals, the results of the study suggest that our facial recognition abilities enable us to deal with thousands of faces.
“Our study focused on the number of faces people actually know- we haven’t yet found a limit on how many faces the brain can handle,” said study co-author Dr. Rob Jenkins. “The ability to distinguish different individuals is clearly important – it allows you to keep track of people’s behavior over time, and to modify your own behavior accordingly.”
The study participants spent an hour writing down as many faces from their personal lives as possible, including people from school, work. and family. Next, they did the same for famous faces, such as actors and politicians.
The volunteers found it easy to add to the list at first, but thinking of new faces became more difficult by the end of the hour. This change of pace allowed the researchers to estimate when they would run out of faces completely.
The participants were also asked who they recognized out of thousands of photographs of famous people. The volunteers needed to recognize two different photos of each person for consistency. Overall, the participants knew between 1,000 and 10,000 faces.
“The range could be explained by some people having a natural aptitude for remembering faces,” said Dr. Jenkins. “There are differences in how much attention people pay to faces, and how efficiently they process the information. Alternatively, it could reflect different social environments-some participants may have grown up in more densely populated places with more social input.”
The average age of the participants was 24, which may lead to further research.
“It would be interesting to see whether there is a peak age for the number of faces we know,” said Dr. Jenkins. “Perhaps we accumulate faces throughout our lifetimes, or perhaps we start to forget some after we reach a certain age.”
The study is published in the journal Royal Society Proceedings B.