Magical Thinking: Outcome Bias Affects Children's Evaluation of Testimony

Magical Thinking: Outcome Bias Affects Children’s Evaluation of Testimony Iris Oved (irisoved@gmail.com) Gail Heyman (gheyman@ucsd.edu) David Barner (barner@ucsd.edu) Department of Psychology, 9500 Gilman Drive San Diego, CA 92093 USA Abstract In a series of three experiments we examined how preschool children assess testimony in relation to the relative desirability of the outcome for themselves and for the individual providing the testimony. The first two experiments reveal evidence for an outcome bias: children are more likely to believe an extraordinary claim when they have little to lose in doing so (Exp.1), and when they stand to gain if the claim is true (Exp. 2). The final experiment (Exp. 3) showed that children are less likely to believe extraordinary claims when the person making the claim has ulterior motives (e.g., stands to potentially gain from the child’s belief). These data show that children’s beliefs acquired from testimony are subject to outcome bias, and that children are capable of exercising skepticism when the source of testimony is likely to have ulterior motives. Keywords: preschoolers; prediction; supernatural events; child beliefs; belief acceptance; testimony. Introduction Beginning in childhood, much of what humans believe about the world derives from indirect evidence, in the form of testimony from other people. In day to day life, we rely on testimony in order to inform a variety of activities like navigation, food choice, and the selection of social partners, where direct evidence is possible but impractical to acquire first hand. We also use testimony to acquire information that is very difficult, if not impossible, to learn oneself – like knowledge of historical events (e.g., the holocaust), scientific facts (e.g., cell structure), and religious beliefs. Crucially, not all information that humans receive from testimony is equally good. In some cases sources may be poorly informed (e.g., a poorly trained doctor), while in other cases they may seek to intentionally mislead, perhaps for their own benefit (e.g., a used car salesman). Consequently, in order to make effective use of testimony, humans must learn to assess the credibility of sources, and to evaluate the information that they provide. Young children, who have relatively little direct experience with the world, and relatively weak prior knowledge against which to assess new information, are both highly dependent on testimony and highly vulnerable to misinformation. A growing body of research has investigated how children assess testimony, focusing on the strategies that they employ to assess the reliability of sources (Kushnir & Sobel 2013, Gelman, 2009; Harris, 2007; Heyman, 2008). For example, these studies find that children as young as 3 to 4 years differentially trust informants based on factors like their age (Jaswal & Neely, 2006; VanderBorght, & Jaswal, 2009), and their previous history of accuracy (Birch, Vauthier, & Bloom, 2008; Corriveau & Harris, 2009; Jaswal & Neely, 2006), and that they sometimes weigh the testimony over their own direct perceptual experience (Jaswal, 2010). There are also other factors that influence how humans evaluate testimony when forming beliefs. In some cases, beliefs that are fundamental to how we understand the world are formed in direct contravention with expert testimony and despite considerable physical evidence to the contrary (e.g., climate change, evolution). In these cases many claims are assessed on the basis of prior convictions, in conformity with cognitive dissonance – i.e., ignoring evidence because of the desire to hold mutually consistent beliefs (Festinger, Riecken, & Schachter, 1956). Also, all else equal, humans are more likely to endorse beliefs that predict positive outcomes over beliefs that predict negative ones – a tendency sometimes referred to as “outcome bias” or the “valence effect” (Cohen & Wallsten, 1992; Granberg & Brent, 1983). In the present study, we investigated how children’s developing ability to assess testimony is affected by their own potential to gain – or to lose – if a claim is true. To test this, we presented children with a situation in which they heard extraordinary claims not directly supported by past experiences (i.e., of supernatural abilities) and in which these abilities had the potential to yield benefits or losses to the child. Previous studies have explored children’s belief in a range of supernatural phenomena as a window into their assessment of testimony, including familiar fictional entities like Santa Claus and the Easter Bunny, religious entities like Angels, and also novel supernatural beings. These studies have investigated differences between children who believe in such entities and those who don’t (Woolley, Boerger, & Markman, 2004), the role that physical evidence plays in belief (Woolley, et al., 2004), and the properties children ascribe to different beings (Shtulman, 2008). However, relatively little attention has been given to whether children are sensitive to the possible outcomes of beliefs – e.g., receiving chocolate eggs, or living eternally in heaven – when assessing their truth. In one past study (Woolley et al., 2004), children were introduced to a fictional character called the Candy Witch. They were told that she would visit them after Halloween to take their candy in exchange for toys. Results showed not only that children were more likely