What People Learn About You From Your Selfies

3 minute read

According to new research, there are scientific reasons why you judged that girl who posted a selfie on Instagram last night.

It’s no secret that people make snap judgments about each other, but the study, conducted by researchers in the Department of Psychology at the University of York, was able to accurately predict what those judgments would be based on facial measurements such as “eye height” and “eyebrow width.”

Previous studies have shown that first impressions often fall into three categories: approachability, dominance, and attractiveness. The researchers at the University of York took 1,000 photographs from the Internet, analyzed the facial features of the subjects (who were all Caucasian), and studied how people reacted to each photograph. They were then able to develop a statistical model that predicted what the viewer’s impression of the face would be based on the measured facial features.

The findings of this study help illuminate the importance of these impressions in an age of social media, in which pictures of faces proliferate and people meet, talk, and even date online. According to the researchers‘ report, curating the perfect photo for these websites isn’t as trivial as it seems. “Some of the features that are associated with first impressions are linked to changeable properties of the face or setting that are specific to a given image,” they wrote. “So things like expression, pose, camera position, lighting can all in principle contribute alongside the structure of our faces themselves.”

Perhaps the most surprising finding was that snap judgments based on a photo could shape the way we respond to a person even after we’ve met them in person. The researchers explain it this way in the introduction to their report: “Although first impressions are formed rapidly to faces, they are by no means fleeting in their consequences. Instead… facial appearance can affect behavior, changing the way we interpret social encounters and influencing their outcomes.”

Less surprisingly, the research showed that “masculine” faces, determined by factors such as cheekbone structure, eyebrow height and skin texture, were seen as dominant, whereas more feminine faces were perceived as more attractive and youthful.

But the researchers also found that the shape and size of a person’s mouth directly affected his or her perceived approachability, and that larger eyes tend to predict higher levels of attractiveness.

So it’s time to stop making fun of people who obsess over choosing their profile picture. Richard Vernon, a PhD student who worked on the study, said, “Showing that even supposedly arbitrary features in a face can influence people’s perceptions suggests that careful choice of a photo could make (or break) others’ first impressions of you.”

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Write to Tessa Berenson at tessa.Rogers@time.com