One of the best documented findings in psychology is the halo effect, a bias where you unconsciously take one aspect of somebody as a proxy for their overall character. It's why we think beautiful people are good at their jobs, even when they aren't necessarily.
As psychologist and writer Scott Barry Kaufman notes, the halo effect works in other ways too.
In a 2014 Chinese study, more than 100 young people looked at images of men and women's faces and rated them on attractiveness. Each face pictured was paired with a word that described either a positive personality trait - like kindness or honesty - or a negative personality trait, like being evil or mean.
Results showed that the people described with positive traits were rated more attractive.
"Even though beauty is an assessment of fitness value, there is no reason why assessment of fitness needs to be purely physical," Kaufman writes, meaning that acting kind can make you appear more attractive.