Within a few seconds of seeing someone — whether on a date or at the grocery store — we decide on numerous things about them, from how smart they are to how likely they are to commit a crime.
Surprisingly, our first impressions can be remarkably accurate in some instances. In others, they can be wildly off base.
Here are a few of the things we determine about people based on how they look.
Thanks to a phenomenon that social psychologists call "the halo effect," we tend to assume that good-looking people possess other positive qualities aside from their looks, such as intelligence and commitment.
Daniel Hamermesh, a University of Texas at Austin psychologist who studies beauty in the workplace, found that, among other things, this cognitive bias means good-looking people tend to get paid more.
Similarly, in a study of male undergrads who were asked to evaluate an essay written by an unnamed female peer, the participants judged the writer and her work more favorably when they were shown a photo of an attractive woman whom they believed to be the writer, as opposed to when they were shown a photo of an unattractive woman or no photo at all.
People can tell a surprising amount about your personality from your portrait.
In a 2009 study, researchers showed participants the photos of 123 undergrads from the University of Texas at Austin in which the undergrads either were told to have a neutral expression or were allowed to pose however they wanted.
No matter which position the people took, the viewers were better than chance at judging the following: how extroverted they were, how high their self-esteem was, how religious they were, how agreeable they were, and how conscientious they were.
In 2013, a group of psychologists, neuroscientists, and computer scientists from Europe and the US had a small group of participants look at portraits of 47 white men and 83 white women and evaluate them first on their height and next on their ability to lead.
The researchers found that people used factors in the photos like gender and face length to make guesses about people's height and then used these same factors when they judged their leadership qualities. Faces that appeared to belong to taller people were rated as belonging to better leaders.
A small 2013 study by researchers at the Center for Behavior Change at the University College London suggested that men with higher testosterone levels were (not surprisingly) more likely to have wider faces and larger cheekbones. Men with these facial features also tended to have more aggressive or status-driven personalities.
In a 2015 study, scientists showed people photos of 10 different people with five different facial expressions and then asked them to rate how friendly, trustworthy, or strong the photographed person appeared.
Not surprisingly, viewers tended to rank people with a happy expression as more friendly and trustworthy than those with angry expressions. They also tended to rate people with broad faces as stronger.