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Key points
- Face masks can disrupt face recognition. During the pandemic, people have experienced difficulty recognizing well-known friends wearing masks.
- Seeing someone without a mask and then with one makes recognition difficult.
- Recognizing someone’s entire face when you’ve only seen them in a mask is also surprisingly difficult.
Bank robbers wear masks for a reason. Masks make it harder to recognize a person. You may have noticed this over the last two years as the Covid pandemic has raged. You fail to recognize a friend when they wear a mask. And now, you might have problems recognizing someone you met during the pandemic when you see them without a mask.
The Pandemic, Face Masks and Disrupted Face Recognition
Many states, communities, and businesses will soon be dropping Covid mask requirements. The CDC has updated the guidance on masking based on Covid case numbers dropping as the Omicron surge passes. If you have lived somewhere where people have been routinely wearing masks, this is likely to bring a real change. Suddenly, you may be able to see a person’s entire face. And if this is someone you’ve only known since the pandemic, you may have never seen them without a mask. Will you recognize them?
Of course, you have probably already experienced problems recognizing people wearing masks. Maybe you have friends you’ve known for a while – you’ve always been able to recognize them. But when the masks came out, it was like attending a masquerade ball. You might think someone looked familiar, but you may have had problems recognizing them.
I’ve experienced this in my role as a college professor. When we meet in a classroom, my students wear masks. I have gradually learned to recognize them with their masks. Repeatedly seeing the upper part of their faces, the eyes, hair, and forehead has allowed me to learn my students eventually.
But then a student visits my Zoom office hours, and I see them on-screen. Their whole face is revealed. And I often experience a shock. I fail to recognize them immediately. They just don’t look right. Somehow seeing the whole face is disruptive. They don’t look the way I expected them to – not that I really know how I expected them to look.
Masks Disrupt Both When Added to a Face and When Taken Off
What I find interesting is that the problem of recognizing masked and unmasked faces goes in both directions. In a nice investigation from before Covid, Manley et al. (2019) looked at the ability to recognize masked and unmasked faces. If you saw someone wearing a mask, trying to recognize them later was actually harder if you saw their whole face than if you saw them in a mask again. It worked the other direction too. If you saw their whole face first, then recognition was better if seeing the whole face again than if you saw them masked.
Since the onset of Covid, other researchers have also looked at whether masks disrupt face recognition. In an interesting demonstration, Carragher and Hancock (2020) found that not only was recognition of new faces disrupted, but so was the recognition of familiar faces. In other words, if you are approached by a friend wearing a mask, you may fail to recognize them at first.
Face Recognition Resiliency
The critical finding is that the transition between wearing a mask and seeing someone’s full face disrupts recognition for new faces and familiar ones. But while the disruption is meaningful, face recognition is nonetheless robust. People still correctly recognized most of the faces they saw in these studies. And recognition of people in real settings, as opposed to simply looking at pictures, is likely to be even better.
With seeing a person, you have access to more information than just the face. You have the entire body, the way they move, and how they sound. This means that while masks disrupt face recognition, we can nonetheless recognize people wearing masks. So this meaningful disruption in recognition is not an excuse to not wear a mask. Your friends will still recognize you, although they may be a little slower to do so.
The Amazing Nature of Face Recognition
Face recognition is an amazing skill. Almost everyone can recognize the faces of familiar people (even when we can’t remember where we met them). But face recognition is particularly interesting because of the way we recognize faces. If we see a person’s whole face, we process that differently than if we only see a few features.
We engage in holistic processing. We recognize a part of a face better when seen in the face again than when seen alone. Someone’s eyes would not look the same on a different face. We are also more dependent on face recognition orientation than on other objects.
Recognizing upside-down faces is really hard. It’s also harder to notice something odd about an upside-down face than a right-side-up face. This is a cool phenomenon known as the Thatcherization effect (Thompson, 1980). Just google ‘thatcherized faces’ to see some funny and disturbing examples of faces that have been changed. When those changed faces are upside-down, they can look fine. But when you flip them over – look out.
We shouldn’t be surprised that masks disrupt face recognition. The interesting part is that masks will disrupt twice. Masks disrupted the recognition of people when we put them on early in the pandemic. And now masks will disrupt recognition as we remove them at the end of the Omicron surge. But face recognition remains remarkably resilient, and you will be able to recognize your friends.
References
Carragher, D. J., & Hancock, P. J. (2020). Surgical face masks impair human face matching performance for familiar and unfamiliar faces. Cognitive research: principles and implications, 5(1), 1-15.
Manley, K. D., Chan, J. C., & Wells, G. L. (2019). Do masked-face lineups facilitate eyewitness identification of a masked individual?. Journal of Experimental Psychology: Applied, 25(3), 396-409.
Thompson, P. (1980). Margaret Thatcher: A new illusion. Perception, 9, 483-484.
