The Brain and Behavior 77
ment of ways of explaining and predicting behavior, it might
seem at first that current neurophysiological findings are of
little value. Certainly, the neurophysiologists of 1900 pro-
vided a clear, simple, mechanical model which early psy-
chologists could and did use to develop their theories. Con-
temporary neurophysiology does not provide such a model,
but, by revealing the complexity and flexibility of man’s struc-
tural characteristics, it forces psychology to develop richer
and more refined ways of specifying both behavior and the
conditions under which it occurs. Such a specification will be
necessary for the development of neurophysiology itself, for-
as Harlow (1958) has pointed out and the material in this
paper can illustrate: “no interdisciplinary research (in this
area) can be better than the behavioral measures which pro-
vide its dependent variable or variables” (p. 5).
To the extent that Harlow’s statement is relevant, it would
seem that tire differences in the results of research on sensory-
motor, intellectual, and emotional processes noted in the
preceding sections of this paper might be related to differ-
ences in the adequacy with which the behaviors involved
for each can be specified. Observations of sensory and motor-
processes can be made both objective and measurable.
Studies of intellectual processes are less objective, but it is
still possible to specify criteria for their measurement. Judg-
ments about emotional processes are neither objective nor
measurable. To the writer it would thus appear that, follow-
ing Harlow, the future of research on the relations between
the brain and behavior would depend more on the adequacy
with which we can refine our techniques for measuring be-
havioral variables and less on developments in neurophysi-
ology, neuroanatomy, or biochemistry. Tlius, although re-
search in neurophysiology since 1900 has not resulted in a
model for explaining and predicting human behavior, it has