Abstract

The objective of the present thesis was to examine infants' understanding of other people's intentions. The first paper was designed to systematically investigate whether the tasks currently being used to tap into infants' understanding of intentional action are actually measuring the same underlying abilities. Infants completed two visual attention tasks when they were 10 months of age: a goal-detection task and an action-parsing task. Approximately four months later, infants were invited back to the laboratory to complete two imitation tasks: a behavioral re-enactment task and a selective action imitation task. Infants' concurrent performances on the visual attention tasks were linked; however, no association between their performances on the imitation tasks was observed. Interestingly, infants' performances on the visual attention tasks at 10 months predicted their performance on the behavioural re-enactment task, but not their performance on the selective action imitation task, at 14 months. In the second paper, the issue of developmental continuities was explored. The goal of this paper was to investigate whether infants' performance on the selective imitation of intentional actions task would predict their use of internal state language and/or their theory of mind abilities later on. Towards this purpose, 14- and 18-month-olds completed an imitation task that required them to distinguish intentional from accidental actions. At approximately 32 months, children's use of internal state terms was assessed via parental report. Finally, when children were 4 years of age, they were retested with an interactive game measuring intention understanding, a battery of general theory of mind tasks, and the Peabody Picture Vocabulary Test. Importantly, infants' performance on the selective action imitation task was linked to their performance on the preschool intention task. Moreover, children's use of internal state language at 32 months predicted their theory of mind skills at 4 years of age. Taken together, the results of the present thesis support the hypothesis that there is developmental continuity in children's understanding of intention from infancy through the preschool years. Results from these two papers also provide evidence to support the validity of various experimental procedures that are currently being used to tap infants' understanding of intentional action