Department of Psychology, University of Wolverhampton, UK.
Br J Psychol. 2010 Nov;101(Pt 4):621-35. doi: 10.1348/000712609X479384. Epub 2010 Feb 24.
Previous studies demonstrate that people high in delusional ideation exhibit a data-gathering bias on inductive reasoning tasks. The current study set out to investigate the factors that may underpin such a bias by examining healthy individuals, classified as either high or low scorers on the Peters et al. Delusions Inventory (PDI). More specifically, whether high PDI scorers have a relatively poor appreciation of sample size and heterogeneity when making statistical judgments. In Expt 1, high PDI scorers made higher probability estimates when generalizing from a sample of 1 with regard to the heterogeneous human property of obesity. In Expt 2, this effect was replicated and was also observed in relation to the heterogeneous property of aggression. The findings suggest that delusion-prone individuals are less appreciative of the importance of sample size when making statistical judgments about heterogeneous properties; this may underpin the data gathering bias observed in previous studies. There was some support for the hypothesis that threatening material would exacerbate high PDI scorers' indifference to sample size.
先前的研究表明，具有妄想观念的人在归纳推理任务中表现出数据收集偏见。本研究旨在通过检查彼得斯等人的妄想清单（PDI）得分较高或较低的健康个体，来探讨可能导致这种偏见的因素。具体来说，高 PDI 得分者在进行统计判断时，对样本量和异质性的理解是否相对较差。在实验 1 中，高 PDI 得分者在对肥胖这一人为的异质特性进行概括时，从 1 个样本中得出的概率估计值较高。在实验 2 中，该效应得到了复制，并且在与攻击性这一异质特性相关的判断中也得到了观察。研究结果表明，易产生妄想的个体在对异质特性进行统计判断时，对样本量的重要性认识不足；这可能是先前研究中观察到的数据收集偏见的基础。有一些证据支持这样的假设，即威胁性材料会加剧高 PDI 得分者对样本量的漠不关心。
