Abstract thematic roles in infants' representation of social events.

Infants' thoughts are classically characterized as iconic, perceptual-like representations. Less clear is whether preverbal infants also possess a propositional language of thought, where mental symbols are combined according to syntactic rules, very much like words in sentences. Because it is rich, productive, and abstract, a language of thought would provide a key to explaining impressive achievements in early infancy, from logical inference to representation of false beliefs.