Department of Psychology.
Department of Psychology, Plymouth University.
J Exp Psychol Learn Mem Cogn. 2014 Mar;40(2):544-54. doi: 10.1037/a0034887. Epub 2013 Nov 11.
Base-rate neglect refers to the tendency for people to underweight base-rate probabilities in favor of diagnostic information. It is commonly held that base-rate neglect occurs because effortful (Type 2) reasoning is required to process base-rate information, whereas diagnostic information is accessible to fast, intuitive (Type 1) processing (e.g., Kahneman & Frederick, 2002). To test this account, we instructed participants to respond to base-rate problems on the basis of "beliefs" or "statistics," both in free time (Experiments 1 and 3) and under a time limit (Experiment 2). Participants were given problems with salient stereotypes (e.g., "Jake lives in a beautiful home in a posh suburb") that either conflicted or coincided with base-rate probabilities (e.g., "Jake was randomly selected from a sample of 5 doctors and 995 nurses for conflict; 995 doctors and 5 nurses for nonconflict"). If utilizing base-rates requires Type 2 processing, they should not interfere with the processing of the presumably faster belief-based judgments, whereas belief-based judgments should always interfere with statistics judgments. However, base-rates interfered with belief judgments to the same extent as the stereotypes interfered with statistical judgments, as indexed by increased response time and decreased confidence for conflict problems relative to nonconflict. These data suggest that base-rates, while typically underweighted or neglected, do not require Type 2 processing and may, in fact, be accessible to Type 1 processing.
基数忽视是指人们倾向于低估基本比率概率，而偏向于诊断信息。人们普遍认为，基数忽视的发生是因为处理基本比率信息需要费力的（第二类型）推理，而诊断信息可以通过快速的、直观的（第一类型）处理来获取（例如，Kahneman 和 Frederick，2002）。为了检验这一说法，我们要求参与者在自由时间（实验 1 和实验 3）和限时条件下（实验 2）根据“信念”或“统计数据”来回答基本比率问题。参与者被给予带有明显刻板印象的问题（例如，“Jake 住在一个豪华郊区的漂亮房子里”），这些问题与基本比率概率相冲突或一致（例如，“Jake 是从 5 名医生和 995 名护士中随机挑选出来的，用于冲突情况；995 名医生和 5 名护士用于非冲突情况”）。如果利用基本比率需要第二类型的处理，那么它们不应该干扰基于信念的快速判断的处理，而基于信念的判断应该始终干扰基于统计数据的判断。然而，基本比率与刻板印象一样，会干扰基于信念的判断，这表现为冲突问题的反应时间增加，信心降低，而与非冲突问题相比。这些数据表明，基本比率虽然通常被低估或忽视，但不需要第二类型的处理，实际上可能是通过第一类型的处理来获取的。
