Proceedings of the Annual Meeting of the Cognitive Science Society

When A causes B and B causes C, under what conditions isA a good explanation for the occurrence of C? We proposethat distal causes are only perceived to be explanatory if thecausal mechanism is insensitive to inessential variations ofboundary conditions. In two experiments, subjects first ob-served deterministic A → B → C relationships in a single ex-emplar of an unknown kind. They judged A to be crucial forC by default. However, when they subsequently learned thatthe causal mechanism fails to generate the A → C dependencyin other exemplars of the same kind, subjects devalued A asa crucial explanation for C even within the first exemplar. Werelate these findings to the idea that good explanations pick outportable dependency relations, and that sensitive causes fail tomeet this requirement.