Communicating shared knowledge in infancy.

Object-directed emotion expressions provide two types of information: They can convey the expressers' person-specific subjective disposition toward objects, or they can be used communicatively as referential symbolic devices to convey culturally shared valence-related knowledge about referents that can be generalized to other individuals. By presenting object-directed emotion expressions in communicative versus noncommunicative contexts, we demonstrated that 18-month-olds can flexibly assign either a person-centered interpretation or an object-centered interpretation to referential emotion displays. When addressed by ostensive signals of communication, infants generalized their object-centered interpretation of the emotion display to other individuals as well, whereas in the noncommunicative emotion-expression context, they attributed to the emoting agent a person-specific subjective dispositional attitude without generalizing this attribution as relevant to other individuals. The findings indicate that, as proposed by natural pedagogy theory, infants are prepared to learn shared cultural knowledge from nonverbal communicative demonstrations addressed to them at a remarkably early age.