Face Time: How many faces can one person recognise?
Ready for my close up?
I came across an article from the Guardian which claimed that we humans can recognise up to 5000 individual faces. Certainly more than our human ancestors ever had to differentiate between in our hunter gather past; Maximum group size was estimated to be in the region of 150 members (Dunbar. et al, 2007). It begs the question why would we need to recognise so many people?
The original study under taken by the head of Psychology at the University of York and published in Royal Society of Biology proceedings, link here.
There are a few things about the study itself which stand out to me, although I am not nor claim to be an expert on psychology studies, please comment if you feel I am been unfair:
- Small sample size (26)
- First part of the study has no way to confirm the participant isn't lying
- The second part of the study relied on recognising famous people, we all have different exposure levels to the media.
- Mixing two studies together to draw a conclusion
A small sample size means that the results may not be representative of the population at large. In this case it is exaggerated as all the people undertaking the study were undergraduate students at the university which falls into a classic problem with a lot of psychological studies whereby study's are basically examining the psychology of middle class white young adults.
Part one of the study relied on the individuals undertaking the study to conjure a mental image of a person’s face and noting that down. There was no way to confirm the person was telling the truth or not.
All of us have different amount of exposure to famous people, while some may spend their days reading gossip style magazines and soaking up television others may rarely come across that type of media, the total is subject to personal preferences and the variability between people.
Main main issue with the study is that it seems to be two different experimental designs put into one study. Part one relies on creating a mental image which is unconfirmed whereas part 2 relied on looking at pictures of celebrities, a positive or hit, was when the participant rightfully recognised two different images as the same individual. The data from both studies is then combined to give the 5000.
Criticism aside, the weighting of the publication and those undertaking the study lend considerable credibility to the evidence presented, it may be simply the spin the article gives. The original study estimates that individuals recognise between 1000–5000 faces which in actuality looking back at the case of a ancient hunter gathers in a group of around 150, possibly coming into contact with other groups along the way and given the length of a lifetime isnt so implausible in my view.
Could it be that modern life itself and our early exposure to the media and the sheer amount of humans around, has given us the number of people we are able to recognise. The ability to separate faces in our day to day life is crucial to determine friend from foe and a valuable skill, I look forward to hearing the latest developments in this story.
Thanks for reading.
References
Dunbar. R, Barrett.L, Lycett.J, (2007) ‘The Social Whirl’, Evolutionary Psychology, London, Clays LTD
R. Jenkins, A. J. Dowsett, A. M. Burton (2018) ‘How many faces do people know?’, Proceedings Of the Royal Society Of Biology, [Vol] 285, [Online]. Available at http://rspb.royalsocietypublishing.org/content/285/1888/20181319 (accessed 25/10/18)
Sample, I. (2018) ‘ Psychologists’ face off reveals humans can recognise 5,000 people’, The Guardian, [Online]. Available at https://www.theguardian.com/science/2018/oct/10/how-many-faces-average-person-recognises-5000 (Accessed 25/10/18)
Image used courtesy of :
© Breda Dance Music / PVP Media / Patrick
