Dual Routes to Cognitive Flexibility: Learning and Response-Conflict Resolution in the Dimensional Change Card Sort Task Michael Ramscar University of Tübingen Melody Dye Indiana University Jessica W. Gustafson and Joseph Klein Stanford University Cognitive control, the ability to align our actions with goals or context, is largely absent in children under four. How then are preschoolers able to tailor their behavior to best match the situation? Learning may pro- vide an alternative route to context-sensitive responding. This study investigated this hypothesis in the Dimensional Change Card Sort (DCCS), a classic test of cognitive control that most under-fours fail. A train- ing intervention based on learning theoretic principles proved highly effective: Three-year-olds who learned about DCCS rules and game contexts in a card-labeling task, subsequently transferred this knowledge to sort- ing in the DCCS, passing at more than 3 times the rate of controls (N = 47). This surprising finding reveals much about the nature of the developing mind. Although a 3-year-old girl might appear to simply be a smaller version of her 4-year-old brother, stud- ies have revealed some surprising differences between them: While her older brother will success- fully pass most of the tasks that have been devised to test the cognitive capabilities of the very young, odds are that she will fail every one of them. At test, a typical 4-year-old can ably navigate the con- flicting dimensions of appearance and reality, cor- rectly judge questions of false belief, successfully switch between competing rules in the Dimensional Change Card Sort (DCCS), and when faced with a forced choice task, reliably choose between two alternatives according to their prior probabilities. An average 3-year-old, on the other hand, will max- imize in that same task (fixating on the most likely response), fail to distinguish reality from false belief and appearance from reality in standard batteries, and fail to switch from one sorting rule to another in the DCCS, even when the new rule is clearly stated (for reviews, see Diamond, 2002; Hanania & Smith, 2009; Ramscar & Gitcho, 2007). Over the past two decades, the underlying causes of these phenomena have been much debated, and many conflicting explanations have been offered to account for 3-year-olds’ curious performance in these tasks (see, e.g., cognitive control & complexity theory, Zelazo, Müller, Frye, & Marcovitch, 2003; active vs. latent representations, Cepeda & Munakata, 2007; Diamond, Carlson, & Beck, 2005; Morton & Munakata, 2002; Yerys & Munakata, 2006; atten- tional inertia, Kirkham, Cruess, & Diamond, 2003; redescription, Kloo & Perner, 2005; Kloo, Perner, Kerschhuber, Dabernig, & Aichhorn, 2008; negative priming, Müller, Dick, Gela, Overton, & Zelazo, 2006; Perner, Stummer, & Lang, 1999). While the bulk of these proposals have been aimed at account- ing for why 3- and 4-year-olds perform so differ- ently, an equally puzzling question has been accorded rather less attention: Given the inflexibility of thought revealed in these tests, why is this rigidity so difficult to detect in the normal course of events? Why is it that young children appear to be capable of responding in flexible and context sensitive ways in some situations, but not in others (Brooks, Han- auer, Padowska, & Rosman, 2003; Deák, 2003)? Here, we outline a solution to this puzzle, based on a consideration of the different ways in which a This material is based on work supported by the National Science Foundation under Grants 0547775 and 0624345 and by the National Science Foundation/IGERT Training Program in the Dynamics of Brain-Body-Environment Systems at Indiana Uni- versity. We are grateful to Natasha Kirkham, Sharon Thompson- Schill, and Stewart McCauley for discussion of these ideas. Correspondence concerning this article should be addressed to Michael Ramscar, Department of Linguistics, Eberhard Karls University, Tübingen, Germany 72074. Electronic mail may be sent to michael.ramscar@uni-tuebingen.de. © 2013 The Authors Child Development © 2013 Society for Research in Child Development, Inc. All rights reserved. 0009-3920/2013/xxxx-xxxx DOI: 10.1111/cdev.12044 Child Development, xxxx 2013, Volume 00, Number 0, Pages 1–16