Defining Psychology and Its Methods

Changes in the psychological experiment in apparatus and methods and the shift in roles of observer and experimenter occurred amid debate over the subject matter of psychology and the methods appropriate to it. The growth in the range of subject matter under experimental investigation and in the methods employed in the study of psychology reflected James McKeen Cattell’s definition of psychology’s subject matter as anything that a psychologist is interested in, as a psychologist (Cattell, 1947a). The experimental psychology that arose in North America resembled the research practices of G. E. Müller more than those of Wilhelm Wundt in the range of topics addressed in the laboratory and the apparatus and methods that were employed. The psychology that evolved in college and university departments of philosophy and, as the century matured, in independent
departments of psychology reflected the functional spirit of the mental philosophers and the influence of the theory of evolution. Mental philosophy had attempted to describe how mind worked, how its cognitive and conative processes operated to produce volitional acts. American psychologists, imbued with the spirit of evolutionary theory, were focused on the
utility of mind and consciousness in the adaptation of species and individuals to the environment. This concern with function (what is mind for? what is its function? —presumably, to aid adaptation) was coupled with other aspects of function, namely, how mind works (how does it function?) and on what mind depends (of what is mind a function? how complex must a nervous system be before mind becomes possible?). These implicit and broad concerns for mental function in psychology were made more explicit and embodied in a selfconscious school of psychology by James Rowland Angell (1869–1949) in response to the programmatic statement of E. B. Titchener (1867–1927), who advocated a structural
psychology. These schools of thought were but two among general systematic positions that competed for dominance in psychology (Heidbreder, 1933; Murchison, 1926, 1930;
Woodworth, 1948).