The central problem in the history of animal behavior has been the inability to perceive the phenotype as the result of an interaction between genome and environment, despite the considerable lip service paid to the interaction. In North America the comparative study of animal behavior was overshadowed by the growth of an experimental psychology that produced the general-process view of learning, holding that the mechanisms underlying learning are much the same in all species. That made evolution irrelevant. During the same period ethology emerged in Europe as the study of naturally occurring behavior in an evolutionary context. Because evolution is fundamental to ethology, the genetic basis of behavior was a central precept. Ethology and psychology collided after World War II. After a vigorous exchange on the issues, a synthesis by Robert Hinde materialized, one that advanced the study of behavior and produced a sophisticated understanding of nature and nurture. A few decades later sociobiology appeared and was immediately assailed for making what were seen as unwarranted extensions from animal to human behavior, and for emphasizing genetic control of behavior. Much of the debate that ensued was distractingly political and threw little light on the scientific merits of the issues although it moderated the stance of sociobilogists; on the other hand, the politically inspired debates may have harmed the field of animal behavior.