Summary: A new study reveals that, on average, we are able to recognize 5,000 different faces.
Source: University of York.
For the first time scientists have been able to put a figure on how many faces people actually know- a staggering 5,000 on average.
The research team, from the University of York, tested study participants on how many faces they could recall from their personal lives and the media, as well as the number of famous faces they recognised.
Humans have typically lived in small groups of around one hundred individuals, but the study suggests our facial recognition abilities equip us to deal with the thousands of faces we encounter in the modern world – on our screens as well as in social interactions.
The results provide a baseline with which to compare the “facial vocabulary” size of humans with facial recognition software that is increasingly used to identify people at airports and in police investigations.
Dr Rob Jenkins, from the Department of Psychology at the University of York, said: “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.
“The ability to distinguish different individuals is clearly important–it allows you to keep track of people’s behaviour over time, and to modify your own behaviour accordingly.”
For the study, participants spent an hour writing down as many faces from their personal lives as possible – including people they went to school with, colleagues and family. They then did the same for famous faces, such as actors, politicians, and other public figures.
The participants found it easy to come up with lots of faces at first, but harder to think of new ones by the end of the hour. That change of pace allowed the researchers to estimate when they would run out of faces completely.
The participants were also shown thousands of photographs of famous people and asked which ones they recognised. The researchers required participants to recognise two different photos of each person to ensure consistency.
The results showed that the participants knew between 1,000 and 10,000 faces.
Dr Jenkins added: “The range could be explained by some people having a natural aptitude for remembering faces. 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 mean age of the studies participants was 24 and, according to the researchers, age provides an intriguing avenue for 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.”
Source: Shelley Hughes – University of York
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to Dr Rob Jenkins, University of York.
Original Research: Open access research for “How many faces do people know?” by R. Jenkins, A. J. Dowsett, and A. M. Burton in Royal Society Proceedings B. Published October 10 2018.
How many faces do people know?
Over our species history, humans have typically lived in small groups of under a hundred individuals. However, our face recognition abilities appear to equip us to recognize very many individuals, perhaps thousands. Modern society provides access to huge numbers of faces, but no one has established how many faces people actually know. Here, we describe a method for estimating this number. By combining separate measures of recall and recognition, we show that people know about 5000 faces on average and that individual differences are large. Our findings offer a possible explanation for large variation in identification performance. They also provide constraints on understanding the qualitative differences between perception of familiar and unfamiliar faces—a distinction that underlies all current theories of face recognition.