The role of inhibitory control in false belief understanding

The aim of this study was to establish the nature of the relations between inhibitory control (IC) and false belief understanding (FBU). Twenty-eight children, participating in an experimental condition, were tested on a battery of FBU and IC tasks every four weeks for six phases of testing. A control group of 14 children completed the battery only at the first and last phases of testing. Comparisons between the performance of the control and experimental groups showed that aggregate FBU scores and some IC tasks were susceptible to practice effects. Regression analysis at the group level found that early IC predicted later FBU, but that early FBU did not predict later IC. The individual children's profiles of performance supported this sequence of development, as the majority of children had good IC before developing good FBU. However, this sequence of development was not unique as a few children had good FBU skills before having good IC. Finally, trial-by-trial analyses showed that fluctuations in children's aggregate FBU scores could not be explained by similar fluctuations in IC, as would be expected by 'expression' accounts of the FBU/IC association. Further analyses considered task validity and the role of verbal ability.