The Role of Overarching Goals in Infants’ Developing Mental State Attributions: The Transition from Teleological to Mentalistic Representation

As adults, we can consider the motivations behind the actions of others, such as what their overarching goals might be and whether these are driven by mental states such as desires. But how does this ability develop? In this thesis, I present a series of five experiments that aimed to explore infants’ understanding of overarching goals and whether this understanding is related to their understanding of others’ diverse desires. In Experiments 1-4, we presented 10- to 12-month-old infants with an actor selectively reaching for one of two functional objects, either a cup or a spoon. In Experiment 1 (N=16), when this selective reach was made in isolation, infants attributed a specific object goal to her. In Experiment 2 (N=16), this selective reach was made in the presence of an overarching goal context and infants did not attribute a specific object goal once the context was removed. Experiments 3 (N=16) and 4 (N=16) demonstrated that the effect of an overarching goal also depended on the actor’s visual access and experience with the objects. Together, these results suggest that by the first birthday, infants can attribute overarching goals and expect these overarching goals to constrain specific object goals. In Experiment 5, (N=60), we wanted to explore whether an understanding of overarching goals is related to an understanding of diverse desires, and whether this relationship is facilitated by parental language. Across four tasks, we found that 18- to 21-month-olds were not able to consider the mental states of others when inferring which object an actor was asking for. Additionally, we found that parents’ use of goal-directed language was related to their child’s vocabulary, such that infants with lower productive vocabularies had parents who used more goal-directed language. We also found a similar relation when comparing parental speech to infants’ task performance, such that parents whose infants got fewer trials correct tended to use more desire and goal-directed language. We believe these results suggest that parents may use desire and goal-directed language to compensate or scaffold their child’s understanding of goals and desires, specifically when their child does not show competence in related tasks. Overall, I suggest that an exposure to repeated behaviours through the form of overarching goals may facilitate the development of early theory of mind, and that parental language is one way in which a child’s environment may scaffold this process.