Final answer:
Hildegard Peplau's theory of interpersonal relationships in nursing is based on the foundation provided by Sigmund Freud's psychoanalytic principles.
Step-by-step explanation:
The theory of interpersonal relationships developed by Hildegard Peplau was based on the psychoanalytic principles of Sigmund Freud. Peplau's work expanded upon Freud's understanding of the unconscious and the dynamics of personality, applying these concepts to the nurse-patient relationship. Peplau viewed the therapeutic nurse-patient interaction as a key component of nursing practice. Her model identifies four sequential phases in the interpersonal process: orientation, identification, exploitation, and resolution. By incorporating psychoanalytic principles into her theory, Peplau contributed to the psychological and therapeutic dimensions of the nursing profession.