The need to belong is a powerful motivational basis for interpersonal behavior, and it is thwarted by social exclusion and rejection. Laboratory work has uncovered a destructive set of consequences of being socially excluded, such as increased aggressiveness and reduced helpfulness toward new targets. Rejected persons do, however, exhibit a cautious interest in finding new friends. Theory and intuition associate social exclusion with emotional distress, but laboratory research finds instead that the first response is a reduced sensitivity to pain and an emotional insensitivity that hampers empathy and may contribute to a variety of interpersonal behaviors. Self-regulation and intelligent thought are also impaired as a direct result of being rejected.