Extinction of Conditioned Fear: A Test of Wolpe's Reciprocal Inhibition Hypothesis

Wolpe's reciprocal inhibition hypothesis states that fear can be reduced by (a) presenting the fear stimulus, (b) omitting noxious reinforcement, and (c) suppressing fear. An experiment was conducted to test this hypothesis. Seventy-two DBA/2 mice were given fear acquisition training. Next drug and extinction trial (DE) Ss and conventional experimental extinction trial (EE) Ss were administered CS alone trials while drugged with chlorpromazine and saline, respectively. Drug only (D) Ss and no-treatment control (C) Ss were injected with chlorpromazine and saline but were not exposed to the CS. Reciprocal inhibition hypothesis predictions were not supported in postextinction tests. The chlorpromazine (CPZ) extinguished DE mice either did not differ from controls or displayed greater fear.