The moment we sort people into “us” and “them”, we start reading the exact same behavior two different ways. Pick an action, then flip the lens between the two groups — and watch the verdict follow the team, not the deed.
Pick an action
The action is identical both times. Only the team of the person doing it changes.
Same act, whose team?choose an action and a lens to begin
1 · What happened?
2 · Who did it? Flip the lens
The science. Even a coin flip is enough: in Henri Tajfel’s minimal group studies, people handed rewards to their own group for no real reason at all. Muzafer Sherif’s Robbers Cave camp watched the same rivalry ignite in days — and cool only once the two groups shared a common goal.
The tell. Notice the verdict pill never changes with the team — it’s favorable for “us” and denied to “them” every time. Only the excuse flips. That asymmetry is the ultimate attribution error.