In-Groups and Out-Groups
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
An in-group is a group a person identifies with and feels loyalty toward; an out-group is one they define themselves against.
Show
Supporters of rival teams describe identical behavior as passion in themselves and as bad conduct in the others.
Watch for
The boundary itself does the work — the trait distinguishing the groups may be trivial.