“合取谬误”指的是这样一种推理谬误:人们认为单个条件发生的概率要小于多个条件联合发生的概率。由于很多心理学被试都在相关实验中犯下这一谬误,因此就有人认为其普遍存在,进而说明了人类在本性上是非理性的,具有违背概率论的顽固倾向。但本文试图为特定条件下出现的“合取谬误”提供三重合理化辩护。第一,在一定背景知识给定的情况下,若整个合取式从中所得到的被确证度要大于某个合取项从中所得到的被确定度,那对前者的偏好就是合理的;第二,合取式由于往往比合取项包含了更多的信息,因此对采集—狩猎时代人类的生存斗争来说就更具生存指导价值,故而对前者的心理偏好也就可能有着深刻的演化论根源;第三,在赌博中对内在概率较小的合取式的偏好也是合理的。这类偏好虽比对合取项的偏好更难得到满足,但一旦得到满足,其获得的收益也往往更大。 “Fallacy ” refers to the fallacy of reasoning: people think that the probability of occurrence of a single condition is less than the probability of occurrence of multiple conditions. Because many psychology subjects made this mistake in relevant experiments, some people think that they are ubiquitous, which shows that human beings are irrational in nature and have stubborn tendencies to violate the theory of probability. However, this article attempts to provide a triple justification defense for “Fallacy ” arising under certain conditions. First, given a certain background knowledge, the preference of the former is reasonable if the degree of affirmation obtained from the whole affirmative is greater than the degree of affirmation obtained from an affiliation; Second, the conjunctures, which often contain more information than the conjunctive items, are more valuable for survival in the struggle for human existence in the capture-hunting era. Therefore, the psychological preferences of the former may also profoundly evolve On the root causes; Third, it is also reasonable for gambling to favor congruences with a low internal probability. Although such preferences are harder to satisfy than the preferences of the co-opt items, they tend to yield greater benefits once satisfied.