Do Preschoolers Understand Causality? A Critical Look

Do Preschoolers Understand Causality? A Critical Look Heidi Kloos (kloos.6@osu.edu) The Ohio State University, Center for Cognitive Science 211G Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210, USA Vladimir Sloutsky (sloutsky.1@osu.edu) The Ohio State University, Center for Cognitive Science 208C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210, USA Abstract While developmental research commonly claims that children have causal understanding, the extent to which such understanding is present is unclear. The current research is a step towards a more conservative look at children’s understanding of causality. We test whether preschoolers appreciate the difference between causes and effects, a finding that is commonly taken to show causal understanding in adults. A two-phase blocking paradigm was used in which the causal status of the cues was manipulated to be either potential causes (predictive reasoning) or potential effects (diagnostic reasoning). Results of two experiments show a significant difference between preschool children and adults in that only adults but not children exhibit evidence for differentiation between causes and effects. These results cast doubt on the idea that understanding of causality appears early in development. Keywords: Cognitive Science; Psychology; Causal reasoning; Cognitive development; Learning; Developmental experimentation. Introduction There is a growing body of evidence that even young children have understanding of causality, and that they use this understanding in their thinking about the world (see Sobel, Tenenbaum, & Gopnik, 2004, for a review). Initially, this claim has been limited to single-cue events, such as physical events in which a rolling ball propels a stationary object (Oakes & Cohen, 1990). More recently this claim has been extended to multiple-cue events, events in which children have to pick the causally relevant cue among several cues, all of which are associated to the caused outcome (e.g., Sobel, et al., 2004). The goal of the current research is to take a more critical look at young children’s understanding of causality. Our perspective is motivated by the current debate about the structure of adult causal knowledge (for a review see DeHouwer, & Beckers, 2002). While some researchers claim that adults rely on abstract causal knowledge when solving causal problems (e.g., Cheng, 1997; Waldmann & Holyoak, 1992), others claim that that relatively simple attentional mechanisms can explain adults’ performance in such tasks (e.g., Cobos, Lopez, Cano, Almaraz, & Shanks, 2002; Van Hamme & Wasserman, 1994). Given that adults’ causal knowledge is a contested issue, it seems that the presence of causal knowledge in children needs a closer examination. The current study is aimed at placing the findings with children in perspective of the findings with adults. To start, we will briefly describe the developmental evidence of multiple-cue events that was taken to show abstract causal knowledge in children. A variety of studies have been conducted with a so-called Blicket detector, a machine that lights up when a ‘Blicket’ is placed on it (e.g., Gopnik & Sobel, 2000; Sobel et al., 2004). Blickets are objects that turn on the lights of the Blicket detector. Children’s task is to find the Blicket among other similar looking objects, to make the machine go (or to remove the Blicket to turn the machine off). An example of events shown to children is presented schematically in Figure 1 (Sobel et al., 2004; Experiment 1). This task is also referred to as a backward blocking task (or screening-off task). A and B refer to the objects presented to children (i.e., the cues), and the outcome O is the response of the Blicket detector (O+: light on; O-: light off). First, cues A and B were placed simultaneously onto the machine and the Blicket detector was activated (O+). Next, cue A was placed onto the machine alone, and the Blicket detector was activated again. The critical question in the test phase pertained to the causal power of cue B. Do children link it with the outcome O+ (because the machine’s lights were on when cue B was on the machine during training), or do they understand that cue B, while associated to the outcome O+, is not causally related to it? Training 1 A B O+ Training 2 Testing A B O+ O+ or O-? Figure 1: Schematic Procedure of a Backward Blocking Task. Consistent with the authors’ predictions, most 4-year-olds and even some 3-year-olds did not link cue B to the outcome O+. They showed some evidence of blocking cue B. However, the difficulty with this (or similar) finding is