Precursors of a theory of mind: A longitudinal study

The study examined whether the pointing gesture and intentional understanding abilities at 12 and 15 months of age predict the later understanding of perception and intention, as well as the ability to explain others' actions in a psychological way at 39 months of age. Thirty-five infants (18 girls) were administered pointing and intention-understanding tasks at the age of 12 and 15 months. Children were again evaluated at the age of 39 months with perception and intention tasks, and a psychological explanation task. Results showed that only 12-month-olds' comprehension of the pointing gesture with an imperative motive contributed to the prediction of later understanding of perception and mentalistic explanations of actions. Moreover, the ability of 12- and 15-month-olds to understand intentions contributed to the prediction of later preschool understanding of perceptions and intentions. These results indicate that a developmental trajectory in children's understanding of mental states from infancy to childhood is present, but depends on the level of engagement and communication that are required to perform these tasks.