sentence: Many people cooperate if and only if others cooperate in return.
sentences_before: A person is more likely to help another if there is a chance that the other person will help them in return, whether immediately or eventually. This is about reciprocity.
sentences_after: Reputation may become important in this. A person with a good reputation for reciprocity have a higher chance of receiving help even from persons they have had no direct interactions with previously.
concept_name: people
headings: Altruism Evolutionary psychology
categories: Ethics Evolution Sociology