Proceedings of the Annual Meeting of the Cognitive Science Society

The conjunction fallacy (CF) describes a pattern where individuals disregard the principles of probability by assessing certain conjunctive statements as more probable than the individual parts of those statements. The fallacy may be fruitfully reconstructed as the normatively correct assessment of something else than probability, for instance of inductive confirmation or coherence. We argue that these approaches have some counter-intuitive consequences in scenarios that have not yet been experimentally tested. We then suggest a novel explanation of the CF according to which the fallacious reasoning arises due to an assessment of explanatory power.