The Preparedness Theory of Phobias: The Effects of Initial Fear Level on Safety-Signal Conditioning to Fear-Relevant Stimuli.

The preparedness theory of phobias implies that fear-relevant stimuli are biologically contraprepared for safety-signal conditioning. Thus it should be very difficult to establish a pictorial snake as a safety-signal predicting the absence of shock in a Pavlovian conditioned inhibition paradigm. Since this contrapreparedness is postulated as species-wide, the snake stimulus should be an ineffective safety-signal even in those subjects who do not fear snakes. In contrast, the prior fear hypothesis suggests that this difficulty should occur only in those subjects who already fear snakes. To test these hypotheses, subjects reporting either high or low snake fear were exposed to electrodermal conditioning trials designed to establish a fear-relevant CS (a pictorial snake) and a fear-irrelevant CS (a pictorial flower) as safety-signals by nonreinforcing each in compound with a fear-eliciting CS. The results provided marginal support for the prior fear hypothesis. [ABSTRACT FROM AUTHOR]