Human psychological reasoning develops early in life,
with infants demonstrating sophisticated abilities to interpret others' actions, goals,
and mental states. This talk presents a series of studies investigating how infants use
communicative cues to update their understanding of others' goals and beliefs, and
how they evaluate prosocial actions within social contexts. In the first set of studies,
we examined whether infants use verbal information to infer changes in an agent's
psychological states. Using violation-of-expectation paradigms, 12- to 14-month-old
infants interpreted a change in verbal labels as signaling a change in the agent's goal,
suggesting that they flexibly integrate linguistic information into goal reasoning.
Furthermore, 18.5-month-old infants updated agents' false beliefs only when the
verbal interventions were informative, indicating sensitivity to the pragmatic content
of communication. Building on these findings, we explored infants' expectations
regarding prosocial actions. We found that 12- to 16-month-old infants attributed
intentions even to unsuccessful helping behaviors and expected agents to help rather
than hinder others. Moreover, infants anticipated that agents would help those in need
and considered social group membership when evaluating acts of helping and
comforting. They also expected agents to distribute resources fairly between
themselves and others. Together, these findings suggest that infants not only
recognize goal-directed and prosocial behavior but also evaluate the nature and
informativeness of communicative acts, as well as the broader social context. This
research highlights the early emergence of complex, context-sensitive psychological
reasoning and underscores the foundational role of communication in the attribution
of beliefs and intentions.