Ultimate attribution error
The ultimate attribution error is explaining an outside group's bad acts by their character while writing off their good acts as luck or special circumstances. For our own group, we tend to do the reverse.
In everyday life
Staff in one department say a rival department's mistake shows those people are careless, while their own department's mistake was caused by an impossible deadline.
When a player on the rival team helps an injured opponent, you say he only did it for the cameras, but when a player on your team does the same, you say it shows what a good person he is.
Why your mind does this
We rarely have full information about a person or situation, so the brain fills gaps with what usually holds true for similar cases. Relying on categories, rules of thumb and trusted sources saves a huge amount of time and effort. For most of history, following the group and trusting experienced elders was a safe bet.
Its family, in 30 seconds: Stereotypes
How to spot it
Ask whether you would explain the same act the same way if someone from your own side had done it.
How to counter it
Swap the group labels in your head and check whether your explanation still holds.
Same family: Stereotypes
SourcesPettigrew (1979)·Wikipedia