Is bias positive or negative?
Bias can be either positive or negative. However, all forms of bias (whether favorable or unfavorable) prevent us from judging others fairly.
For example, because of explicit bias, a teacher might openly claim that students from a certain ethnic background are exceptionally good in math. Even though this sounds positive, it means that other students are automatically treated as second-rate. For this reason, bias is linked to unfairness and thus has a negative connotation.