On average, possibly somewhere around 5,000, according to researchers from the University of York, England. The findings of their study were published in Proceedings of the Royal Society B on October 09
“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 Dr Rob Jenkins from the Department of Psychology at York. “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.”
First, the research team asked participants to spend an hour and recall as many faces as possible from their personal lives. These included old school friends, co-workers, romantic partners, and more.
For the second part of the study, the participants were asked to recognise more than 3,000 famous faces including actors, singers, sports people, politicians, and other public figures.
While people were initially able to recall many faces quickly, this inevitably slowed down as they kept going. By recording the rate at which their recall slowed down, the researchers were able to estimate when they would hit a dead end.
The results revealed a large range – between 1,000 to 10,000 faces — which would be 5,000 on average.
“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,” Jenkins added. “Alternatively, it could reflect different social environments–some participants may have grown up in more densely populated places with more social input.”
Another major exception here would be the segment of the population who experience ‘face blindness’ or prosopagnosia, a condition which affects the ability to recognise faces. According to a Harvard study conducted in 2006, approximately 2 per cent of Americans have the condition.
As for limitations, the first part of the study largely relied on the honesty of the participants. The method of estimation could also be prone to inaccuracies, though the range provides a very useful baseline for future research. It would help to conduct similar experiments with larger groups as only 25 people were involved in this study.
In addition to understanding why some brains were better at remembering more faces, the researchers also wanted to examine the role of age. Since the mean age of the group was 24, Jenkins believed it may be worth exploring if there is a ‘peak age’ for the brain to accumulate the memories of faces.
Source: Medical Daily