PERCEPTUAL SELECTIVITY AND AMBIVALENCE OF STIMULI.

In the study of motivational determinants of perception, there is a tendency to identify motivational with wish fulfilling. Once it has been demonstrated that needs and values may systematically affect perceptual organization, it is tempting to conclude that perception is the servant of the organism's wishes and at all times strains for the satisfaction of these wishes as far as stimulus conditions will permit. It is true that under some conditions of deprivation, perceptual selectivity favors goal objects and sources of satisfaction, but the evidence is mounting that such is by no means the general rule. Experiments on the perceptual effects of food deprivation provide one example. It is necessary to put the interpretation of motivational factors in perception on a basis broader than is provided by a principle of autistic wish-fulfillment or a single-minded application of the theory of defense mechanisms. Whether perception will appear to be wish-fulfilling and defensive, overvigilant, or realistic depends at least in part on the frequency with which positively and negatively valued hypotheses have been confirmed in the past. No matter how strong the motivational support for any given perceptual hypothesis, confirmation or nonconfirmation from the environment continually modifies the strength of the hypothesis.