The role of social-referential context in verbal and nonverbal symbol learning.

This study examined the role of social-referential context in 13- and 18-month-olds' mapping of verbal and nonverbal symbols to object categories. Infants heard either novel words or novel nonverbal sounds in either a referential or nonreferential context. In all conditions, an experimenter engaged in a social-referential interaction and the label was produced while the infant's attention was directed to the referent. In the referential condition, labels were produced by the experimenter within the context of a familiar naming routine. In the nonreferential condition, labels were emitted from a baby monitor placed near the infant. The study subsequently tested infants' mapping of the symbols to the referent objects using a forced-choice procedure. Although the results for the 18-month-olds were strongest, infants at both ages showed evidence of learning both words and sounds in the referential condition and failed to learn them in the nonreferential condition. Thus, infants successfully learned both words and sounds under the same circumstances at both ages. These findings suggest that the social-referential context, and not the symbolic form per se, determine infants' success at symbol learning.