Surian, L., Caldi, S. & Sperber, D. 2007 Attribution of beliefs by 13-month-old infants. Psychological Science 18, 580-586.

Abstract: In two experiments, we investigated whether 13-month-old infants expect agents to behave in a way consistent with information to which they have been exposed. Infants watched animations in which an animal was either provided information or prevented from gathering information about the actual location of an object. The animal then searched successfully or failed to retrieve it. Infants’ looking times suggest that they expected searches to be effective when—and only when—the agent had had access to the relevant information. This result supports the view that infants’ possess an incipient metarepresentational ability that permits them to attribute beliefs to agents. We discuss the viability of more conservative explanations and the relationship between this early ability and later forms of ‘theory of mind’ that appear only after children have become experienced verbal communicators.