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Language and Theory of Mind: Meta-Analysis of the Relation Between Language Ability and False-belief Understanding


  • This research was supported by a University of Toronto Connaught Research Fellowship and a grant from the Natural Sciences and Engineering Research Council of Canada to JWA. We thank Leslie Atkinson and Ruth Childs for their guidance in completing the analyses for this study, Jodie A. Baird and Eva Filippova for their assistance with coding, and the Theory of Mind research group at the Ontario Institute for Studies in Education, University of Toronto, for assistance in retrieving studies and comments on earlier drafts of this article. We also thank all of the researchers who provided information to supplement that available in published sources.

concerning this article should be addressed to Karen Milligan, The Credit Valley Hospital, Child and Family Services, 2200 Eglinton Avenue W., Mississauga, ON L5M 2N1. Electronic mail may be sent to


Numerous studies show that children's language ability is related to false-belief understanding. However, there is considerable variation in the size of the correlation reported. Using data from 104 studies (N=8,891), this meta-analysis determines the strength of the relation in children under age 7 and examines moderators that may account for the variability across studies—including aspect of language ability assessed, type of false-belief task used, and direction of effect. The results indicate a moderate to large effect size overall that remains significant when age is controlled. Receptive vocabulary measures had weaker relations than measures of general language. Stronger effects were found from earlier language to later false belief than the reverse. Significant differences were not found among types of false-belief task.