2. Initiation rites improve group evaluations
Existing groups don't let others join for free: the cost is sometimes monetary, sometimes intellectual, sometimes physical—but usually there is an initiation rite, even if it's well disguised.
Aronson and Mills (1959) tested the effect of initiation rites by making one group of women read passages from sexually explicit novels. Afterwards they rated the group they had joined much more positively than those who hadn't had to undergo the humiliating initiation. So, not only do groups want to test you, but they want you to value your membership.
