Examined S. Revusky's suggestion that long delay learning of taste aversions in rats can be explained by the "belongingness" or "preparedness" principle. The long-delay capability is attributed to minimal taste interference in the period between cs and ucs, I.e., only tastes have much associability with poisoning and rats ordinarily experience few tastes other than the one designated as cs within a long period prior to poisoning. In experiments with 153 female white rats, it was demonstrated that longer delays led to smaller learned taste aversions, even if no interfering tastes were available during the delay. The explicit introduction of 3 novel or previously poisoned interfering solutions during the delay interval did not prevent a learned aversion to novel sucrose. It is concluded that although the relative absence of interference may contribute to the long delays possible in taste-aversion learning, it cannot be the sole explanation of this phenomenon. (16 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)