Research by Mirella Walker and others.
"We form these immediate impressions of people - we just can't help it," Alexander Todorov, a psychology professor at Princeton University, told Business Insider.
Todorov's lab tests responses to computer-generated faces to model traits associated with perceived attractiveness, trustworthiness, competence, and more.
Todorov warns that these impressions are highly inaccurate. People have many biases, including halo effects - where we assume one positive trait will be followed by others - and stereotypes - where we associate behaviors with looks. Still, the professor says it's worth understanding them, if only to fight them.
We've highlighted some findings from Todorov and others below.