Did you know that humans have a fascinating ability to recognize faces, sometimes even seeing them in places where they don’t actually exist, like on the moon or Mars? This skill is crucial for social animals like us, but the exact process of how we identify faces is still a bit of a mystery. Take the Thatcher effect, for example, which shows that our brains don’t simply accept sensory input when determining what a normal face looks like.

A recent study recently published in the journal Cognition sheds light on how our perception of a person can influence how we see their facial features. Essentially, we tend to think that people with similar personality traits look alike. This social aspect of facial recognition was explored in a study involving approximately 200 volunteers who were shown images of famous faces and asked to match them as quickly as possible.

The study participants, all white men for consistency, were shown images of celebrities like Justin Bieber, George W. Bush, and Vladimir Putin. They were then asked to rate the likelihood of each person having specific personality traits. The results showed that volunteers were more likely to believe that individuals with similar traits looked more alike than those with different traits.

Further studies confirmed these findings, showing that the effect also works in reverse – people with similar faces were perceived to have similar traits. Even when participants were shown unfamiliar faces, they still reported seeing similarities based on the personality traits they were told the individuals possessed.

Lead author Jonathan Freeman from New York University’s Department of Psychology highlighted the impact of social knowledge on facial perception. He explained that our perception of facial identity is influenced not only by physical features but also by the social information we have learned about others, leading us to see alternate identities even when there is no physical resemblance.

This study adds to our understanding of facial recognition as a “social-conceptual” process, suggesting that our perception of a person is intertwined with our perception of their face. Other studies have shown that the context in which we see faces also plays a role in how we recognize them. So, while it may remain a mystery why some volunteers see similarities between Justin Bieber and Vladimir Putin, it highlights the complex interplay between social knowledge and facial perception.