In psychology and other social sciences, the contact hypothesis suggests that intergroup contact under appropriate conditions can effectively reduce prejudice between majority and minority group members. Following WWII and the desegregation of the military and other public institutions, policymakers and social scientists had turned an eye towards the policy implications of interracial contact. Of them, social psychologist Gordon Allport united early research in this vein under intergroup contact theory.

In 1954, Allport published The Nature of Prejudice, in which he outlined the most widely cited form of the hypothesis. The premise of Allport's hypothesis states that under appropriate conditions interpersonal contact could be one of the most effective ways to reduce prejudice between majority and minority group members. According to Allport, properly managed contact should reduce issues of stereotyping, prejudice, and discrimination that commonly occur between rival groups and lead to better intergroup interactions.

In the decades following Allport's book, social scientists expanded and applied the contact hypothesis towards the reduction of prejudice beyond racism, including prejudice towards physically and mentally disabled people, women, and LGBTQ+ people, in hundreds of different studies.

In some subfields of criminology, psychology, and sociology, intergroup contact has been described as one of the best ways to improve relations among groups in conflict. Nonetheless, the effects of intergroup contact vary widely from context to context, and empirical inquiry continues to this day.