Judicious Imitation: Children Differentially Imitate Deterministically and Probabilistically Effective Actions


  • This research was supported by a James H. Ferry Jr. Fund for Innovation in Research Education grant and a McDonnell Foundation Collaborative Initiative Causal Learning grant to L.E.S. Thank you to Elizabeth Baraff Bonawitz, Darlene Ferranti, Noah Goodman, Andrew Shtulman, and Josh Tenenbaum for helpful comments and suggestions—and particular thanks to Rebecca Saxe for help in clarifying the analysis. We are also very grateful to the Discovery Center at the Museum of Science, Boston and participating parents and children.

concerning this article should be addressed to Laura E. Schulz, 46-4011, Massachusetts Institute of Technology, Department of Brain and Cognitive Sciences, 77 Massachusetts Avenue, Cambridge, MA 02139. Electronic mail may be sent to lschulz@mit.edu.


Three studies look at whether the assumption of causal determinism (the assumption that all else being equal, causes generate effects deterministically) affects children’s imitation of modeled actions. These studies show even when the frequency of an effect is matched, both preschoolers (N = 60; M = 56 months) and toddlers (N = 48; M = 18 months) imitate actions more faithfully when modeled actions are deterministically rather than probabilistically effective. A third study suggests that preschoolers’ (N = 32; M = 58 months) imitation is affected not just by whether the agent’s goal is satisfied but also by whether the action is a reliable means to the goal. Children’s tendency to generate variable responses to probabilistically effective modeled actions could support causal learning.