The development of children's theory of mind: The working memory explanation

The hypothesis that a growth in working memory capacity could explain the observed development of theory of mind in preschoolers was tested. Fifty-four 3- to 5-year-olds were administered: two false belief tasks as measures of theory of mind development; two “false” photograph tasks parallel to typical false belief tasks, but involving nonmental representations; the Peabody Picture Vocabulary Test -Revised (PPVT-R); and two working memory capacity measures (backward digit span, BDS, and forward digit span, FDS). A multiple linear regression analysis revealed that BDS significantly predicted performance on both the false belief and false photograph tasks with age and PPVT-R score controlled, but that FDS did not, suggesting that growth in central executive capacity is important in determining children's success or failure on false belief tasks, but that articulatory loop capacity is not. It is concluded that, in general, the findings are consistent with the working memory hypothesis, although subsequent contingency table analysis revealed that success on the BDS task was not necessary for successful performance on theory of mind tasks.