Contiguity vs. Drive-Reduction in Conditioned Fear: The Proximity and Abruptness of Drive-Reduction

This study attempts to determine the conditions under which the response of fear becomes attached to an initially neutral stimulus. Many psychologists, following the lead of Hull,' currently hold that all learning depends upon the occurrence of some form of drive-reduction. Since the development of a functional connection between a formerly neutral stimulus and the response of fear is a form of learning, these psychologists, to be consistent, must hold that the development of such a connection likewise is dependent upon drive-reduction. In contrast, others, including the present authors, believe that the drivereduction formula, while useful in accounting for the selective learning of skeletal responses ('habits'), is not adequate to account for certain other forms of learning-conspicuous among which is that involved in the acquisition of fear. Here, it appears, the conditions of reinforcement are provided by stimulus-contiguity.2 Since one of the best ways of causing a neutral stimulus to acquire the capacity to elicit the response of fear is to pair that stimulus with an electric shock, the difference between the two theoretical positions just described can be reduced to very simple and very specific terms by saying that for Hull and his followers this type of learning depends upon what happens