Animals have been studied in their natural habitat largely because of a history of field research in zoology. Invariant species-specific behaviors have been studied primarily because those behaviors helped zoologists classify species. For example, two early pioneers in ethology, Konrad Lorenz and Charles Otis Whitman, studied the behavior of ducks and pigeons, respectively, because they were interested in classifying those families, and behavior helped them do that. In ducks, sexual behavior proved the most useful, and in pigeons, drinking behavior served the same role. However, ethologists soon branched out to study behavior more generally, beyond its usefulness for classification.
For many years, psychology and ethology were strangers to each other. Psychology developed primarily in the United States, while ethology developed in Europe. Psychology became very concerned with the study of learning, while ethology studied species-specific behaviors. When, in the 1950s, they came into more intimate contact, their different emphases and methods caused them to criticize each other severely. Gradually, however, they came to respect each other's data and methods, and each changed significantly because of their contact. Today, the old disciplinary barriers of the two fields are much lower than in the past.
There are no Nobel prizes for the study of behavior, because when Alfred Nobel created the award, psychology was in its infancy. Several prizes have been awarded for the study of behavior, however, and the first was to three ethologists: Konrad Lorenz, Niko Tinbergen, and Karl von Frisch in 1973. They were awarded the prize in physiology and medicine. Since then psychologists Roger Sperry and Herbert Simon have also been awarded Nobel prizes. Sperry's, too, was in physiology and medicine, Simon's in economics, but both were for psychological research.