McDougall William (1871–1938), British and American (after 1920) psychologist. He was probably the first to define psychology as the science of behavior (Physiological Psychology, 1905; Psychology: The Science of Behavior, 1912) and he invented hormic (purposive) psychology. By the early twentieth century, as psychology strove to become scientific, purpose had become a suspect concept, but following Stout, McDougall argued that organisms possess an ‘intrinsic power of self-determination,’ making goal seeking the essential and defining feature of behavior. In opposition to mechanistic and intellectualistic psychologies, McDougall, again following Stout, proposed that innate instincts (later, propensities) directly or indirectly motivate all behavior (Introduction to Social Psychology, 1908). Unlike more familiar psychoanalytic instincts, however, many of McDougall’s instincts were social in nature (e.g. gregariousness, deference). Moreover, McDougall never regarded a person as merely an assemblage of unconnected and quarreling motives, since people are ‘integrated unities’ guided by one supreme motive around which others are organized. McDougall’s stress on behavior’s inherent purposiveness influenced the behaviorist E. C. Tolman, but was otherwise roundly rejected by more mechanistic behaviorists and empiricistically inclined sociologists. In his later years, McDougall moved farther from mainstream thought by championing Lamarckism and sponsoring research in parapsychology. Active in social causes, McDougall was an advocate of eugenics (Is America Safe for Democracy?, 1921). T.H.L.