复旦学报:社会科学版
複旦學報:社會科學版
복단학보:사회과학판
Fudan Journal(Social Sciences Edition)
2014年
2期
110~118
,共null页
合取谬误 概率论 合理性 自然选择
閤取謬誤 概率論 閤理性 自然選擇
합취류오 개솔론 합이성 자연선택
conjunction fallacy; probability theory; rationality j natural selection
“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.
“閤取謬誤”指的是這樣一種推理謬誤:人們認為單箇條件髮生的概率要小于多箇條件聯閤髮生的概率.由于很多心理學被試都在相關實驗中犯下這一謬誤,因此就有人認為其普遍存在,進而說明瞭人類在本性上是非理性的,具有違揹概率論的頑固傾嚮.但本文試圖為特定條件下齣現的“閤取謬誤”提供三重閤理化辯護.第一,在一定揹景知識給定的情況下,若整箇閤取式從中所得到的被確證度要大于某箇閤取項從中所得到的被確定度,那對前者的偏好就是閤理的;第二,閤取式由于往往比閤取項包含瞭更多的信息,因此對採集—狩獵時代人類的生存鬥爭來說就更具生存指導價值,故而對前者的心理偏好也就可能有著深刻的縯化論根源;第三,在賭博中對內在概率較小的閤取式的偏好也是閤理的.這類偏好雖比對閤取項的偏好更難得到滿足,但一旦得到滿足,其穫得的收益也往往更大.
“합취류오”지적시저양일충추리류오:인문인위단개조건발생적개솔요소우다개조건연합발생적개솔.유우흔다심이학피시도재상관실험중범하저일류오,인차취유인인위기보편존재,진이설명료인류재본성상시비이성적,구유위배개솔론적완고경향.단본문시도위특정조건하출현적“합취류오”제공삼중합이화변호.제일,재일정배경지식급정적정황하,약정개합취식종중소득도적피학증도요대우모개합취항종중소득도적피학정도,나대전자적편호취시합리적;제이,합취식유우왕왕비합취항포함료경다적신식,인차대채집—수작시대인류적생존두쟁래설취경구생존지도개치,고이대전자적심리편호야취가능유착심각적연화론근원;제삼,재도박중대내재개솔교소적합취식적편호야시합리적.저류편호수비대합취항적편호경난득도만족,단일단득도만족,기획득적수익야왕왕경대.
The so-called "conjunction fallacy" occurs when it is theoretically assumed that the conjunction of two conditions is more probable than a single general one. Since a high ratio of subjects are tending to commit this fallacy in psychological experiments, it may be tempting to assume that human-beings are by nature irrational in the sense that most of them cannot avoid violating simple rules of probability theory in practical reasoning. But perhaps philosophers can still defend human rationality by re-interpreting conjunction fallacy. More specifically, three arguments will be provided in this article for rationalizing human's preference of conjunctions rather than conjuncts. First, when certain background information is given, conjunctions partially confirmed by it should be more favorable than conjuncts entirely irrelevant to it. Second, conjunctions are more favorable than conjuncts also from the evolutionary perspective in the sense that the former is routinely more valuable in guiding and forming agents' actions leading to their survival and reproduction. Last, the risk of betting on a conjunction (with a low intrinsic probability value) would sometimes be offset by the higher reward of doing it, whereas the reward of betting on a conjunct is usually lower.