You know so many faces. Your family, friends, co-workers, people you used to know, celebrities, TV personalities, athletes – you can recognize so many faces it is quite incredible. But how many exactly? You probably cannot count them all, but scientists from the University of York have been able to put a figure on how many faces people actually know and it is staggering.

First of all, remember what we are. Before TV and internet people lived in rather small circles. For thousands of years. In medieval times you only met a handful of people in your entire lifetime. Humans naturally don’t gather in huge communities like we have now. And yet, as scientists found, on average we can recognize 5000 faces, which is truly incredible. It is hard to believe this figure, but that is what scientists discovered. In fact, it is just what we know on average – our limit is still unknown.

Recognizing faces is obviously important. Our sense of smell is not that great, which is why we use our facial recognition to know, which people belong to our group, how they behave, how we are supposed to follow them or move away. Scientists invited participants to spend one hour writing down faces they would recognize. At first – their family members, current and former friends and other people from their circle. Then – celebrities, politicians, business leaders and other famous people. Then participants were shown literally thousands of pictures of celebrities. Some people were shown twice to ensure consistency. And so, participants knew from 1000 to 10 000 faces. It is quite a large range, but some people a natural aptitude for remembering faces – they pay more attention to people’s faces.

Some people don’t even look at your face when they are talking with you. That is why for some it is more difficult to remember faces. The range could also be explained by different environments that these people came from – those who come from more densely populated areas will meet more people. And then there is a simple truth of life that some are just not interested in pop culture. Although young people typically are and the mean age of participants was 24. Dr Rob Jenkins, lead author of the study, said: “It would be interesting to see whether there is a peak age for the number of faces we know. Perhaps we accumulate faces throughout our lifetimes, or perhaps we start to forget some after we reach a certain age”.

5000 faces are a lot, but even that number is nothing compared to advanced facial recognition algorithms. On the other hand, it is quite weird that you will never know your number – our brain does not catalogue them, which makes it difficult to count how many face you actually recognize.

Source: University of York