Tipping. Why do we tip in restaurants? I think it is because we care about the opinions of the waiters and waitresses, even when we know we will never meet them again. If the social convention is to pay a tip, and I do not, then I feel shame at the rightful scorn of the waiter. The effect is strongest if the waiter knows that I have not tipped him. I think there is another effect at work, though, that would operate even if I knew the waiter would not blame me. Suppose the waiter thought that Smith was paying for the dinner, and blamed Smith for the lack of a tip, but actually it was I that paid the bill. I will still feel bad. Part of this is guilt-- the feeling that I have done something wrong. Another part, though, is shame-- the feeling that if others only knew, they would disapprove.