The goal of the proposed research is to examine the effects of interpersonal rejection on interpersonal functioning. Study 1 employs a diary method to examine how daily feelings of acceptance or rejection affect next day measures of affiliation. Study 2 manipulates rejection by one person and examines its effect on helping behaviors toward another person who is either approachable or dismissive. Study 3 manipulates rejection by a group and assesses its impact on helping toward a second accepting or neutral group. Study 4 examines the interactive effects of rejection and personality (self-esteem and rejection sensitivity) on aggression (Study 4) and affiliation (Study 5) toward intimates and non-intimates. Study 5 also examines the self-fulfilling nature of rejection expectancies by isolating the specific verbal and nonverbal behaviors exhibited by people who are rejected. The results from these studies are expected to show that rejected people behave in ways that fortify and strengthen interpersonal bonds when they expect to be accepted, but they behave in ways that damage or destroy interpersonal bonds when they expect to be rejected. Implications for reversing the destructive coping behaviors of people high in rejection sensitivity and low in self-esteem are discussed.