Ostracism occurs when someone is ignored and excluded by others. According to Kipling Williams and his colleagues, the act of ostracism is an adaptive response that occurs within groups as a [Page 629]reaction to burdensome members who threaten the group's strength or safety. Ostracism can allow the ostracized individual to correct his or her behavior or seek out other groups to join, thereby ensuring the individual's survival. Al though considered largely a group phenomenon, ostracism can also occur within dyadic relationships, where it is commonly known as the silent treatment.

Since the mid-1990s, researchers have conducted hundreds of experiments assessing the impact of ostracism (and the related phenomenon of rejection) on an individual's physiological responses, cognitions, emotions, and behaviors. A variety of paradigms have been used ...