Eating apples and houseplants: Typicality constraints on thematic roles in early verb learning

Are thematic roles linked to verbs in young children as in adults or will children accept any participant in a given role with any verb? To assess early verb comprehension we used typicality ratings with adults, parental questionnaires, and Intermodal Preferential Looking with children. We predicted that children would look at named targets, would initially associate typical action-patient combinations with verbs, and accept atypical pairings as they get older. Results show that 15-month-olds do not understand verbs yet, 18-month-olds look at typical and atypical targets after naming, 24-month-olds demonstrate preferences for typical items only and 3-year-olds (and adults) accept atypical instances. Thus, children seem to start mapping verbs broadly to action-patient combinations, even implausible ones. Around 24 months they show restricted naming and accept only typical scenes congruent with their experience. By 3 years they have gained independence from this typicality-guided strategy and show adult-like behaviour in accepting even unusual pairings as fitting the verb.