Harry Stack Sullivan, a prominent American psychiatrist and psychoanalyst, developed his ideas on the interpersonal through his extensive clinical experience and observation of human behavior.
Sullivan believed that the interpersonal is a fundamental aspect of human experience and that our relationships with others shape our thoughts, feelings, and behaviors. He drew on his observations of patients, as well as his own personal experiences, to develop his theory of interpersonal relations.
Sullivan's interest in the interpersonal was also influenced by his interactions with other prominent psychoanalysts of his time, including Sigmund Freud and Karen Horney, who also emphasized the importance of social and interpersonal factors in shaping human psychology.
Overall, Sullivan's ideas on the interpersonal were shaped by a combination of his clinical experience, personal observations, and interactions with other influential psychoanalysts of his time.
