Abstract:

The conjunction fallacy in probability judgment refers to a phenomenon of probability judgment bias, which results from violating the conjunction rules of event occurrence probability and regarding that the occurrence probability of conjunction event that contains multiple independent events is greater than that of conjunct events in it. The definition standard of conjunction fallacy is incongruent. The relevant mental mechanism includes causal model theory, confirmation theory and surprise theory and so on, and many factors affect conjunction fallacy, like frequency effect, training effect, individual differences, and many others. Studies in the future should combine the mental mechanism of inverse conjunction fallacy to perfect the existing explanatory theory, meanwhile, the conjunction fallacy in application and its irrationality should be noticed.

Key words: conjunction fallacy, psychological mechanism, effect factors, inverse conjunction fallacy, irrationality