Does language matter for implicit theory of mind? The effects of epistemic verb training on implicit and explicit false-belief understanding

•Significant effects of training on implicit measures of true- and false-belief.•Post-training improvements only observed for children trained with epistemic verbs.•Training effects were not consistent across all contexts of epistemic reasoning.

We examined the effects of epistemic verb training on preschoolers' implicit and explicit inferences about epistemic states. Eighty-four children (mean age 3;5), who initially failed explicit measures of false-belief understanding, were trained with visual scenes of true- and false-belief. Across three training groups, linguistic input was manipulated so that children heard narrations that contained either: (a) the description of an agent's actions without an epistemic verb, (b) a familiar epistemic verb (thinks), or (c) the familiar epistemic verb in contexts of true-belief and a novel epistemic verb (gorps) in contexts of false-belief. Significant post-training improvements were exclusively observed on implicit measures of false-belief and only for children who received training with epistemic verbs. Findings indicate that linguistic training facilitates the implicit processing of epistemic states but these effects may be limited to specific contexts of false-belief reasoning.