The Sullivan Institute, and the communal society sometimes called the Sullivanians that grew out of it, was founded in New York in the 1950s by Saul Newton and Jane Pearce, drawing its name and some of its language from the interpersonal psychoanalysis of Harry Stack Sullivan, though it departed sharply from mainstream psychoanalytic practice. Its distinctive teaching was a radical rejection of the traditional nuclear family, which it regarded as the root source of psychological damage; members were encouraged to loosen or sever ties with parents and to avoid exclusive couple relationships in favor of a more communal, non-monogamous life, with child-rearing arranged collectively.
Over time the therapy practice and its clientele evolved into a tightly knit residential community on Manhattan's Upper West Side, active into the 1980s and involved in cultural and theatrical pursuits. It has since been examined chiefly through the accounts of former members and later historical study, some of which describe the therapists' considerable influence over members' major life decisions, including relationships and the raising of children, and disputes over custody as the community broke up. The group is discussed in the literature on "therapy cults" as an example of how a psychotherapeutic practice organized around strong authority can develop into an all-encompassing community; assessments rest largely on retrospective testimony.