Mere exposure Effect

An unknown student wore a binbag to class every day; Only the professor knew who they were. 

The other students’ attitude toward them went from hostile to friendly just through exposure.

We tend to have a preference for things just because we are familiar with them

See the full study here :

Zajonc, R. B. (1968). Attitudinal effects of mere exposure. Journal of personality and social psychology9(2p2), 1.

Want to know more about biases?

Take-the-best Heurisitc

Rhyme-as-Reason Effect

Humor Effect

Pratfall Effect