Correspondence bias (also known as the fundamental attribution error) is the tendency to overestimate the contribution of lasting traits and dispositions in determining people's behavior, as compared to situational effects. We might see someone kicking a vending machine, and conclude they're an inherently angry person. But maybe they just failed a test, had their driving license revoked, and had the machine eat their money for the third time this week. We think of the other person as an evil mutant and ourselves as righteous actors.
DT Gilbert, PS Malone (1995) The Correspondence Bias (PDF)
“In judging others we can see too well / Their grievous fall, but not how grieved they fell; / Judging ourselves, we to our minds recall, / Not how we fell, but how we grieved to fall.” ―George Crabbe, “Boys at School,” 1819