Reciprocity A mutual exchange between what we give and receive—for example, liking those who like us.
Relative deprivation Feelings of discontent aroused by the belief that one fares poorly compared with others.
Reluctant altruism Altruistic kinds of behavior that result from pressure from peers or other sources of direct social influence.
Replication Repeating a research study to see if the results are similar to those found in the original study.
Resource dilemmas Social dilemmas involving how two or more people will share a limited resource.
Rumination In the context of aggression, rumination involves repeatedly thinking about and reliving an anger-inducing event, focusing on angry thoughts and feelings, and per- haps even planning or imagining revenge.