Differential effects of others' emotional cues on 18-month-olds' preferential reproduction of observed actions.

Infants use others' emotional signals to regulate their own object-directed behavior and action reproduction, and they typically produce more actions after having observed positive as compared to negative emotional cues. This study explored infants' understanding of the referential specificity of others' emotional cues when being confronted with two actions that are accompanied by different emotional displays. Selective action reproduction was measured after 18-month-olds (N = 42) had observed two actions directed at the same object, one of which was modeled with a positive emotional expression and the other with a negative emotional expression. Across four trials with different objects, infants' first actions matched the positively-emoted actions more often than the negatively-emoted actions. In comparison with baseline-level, infants' initial performance changed only for the positively-emoted actions, in that it increased during test. Latencies to first object-touch during test did not differ when infants reproduced the positively- or negatively-emoted actions, respectively, indicating that infants related the cues to the respective actions rather than to the object. During demonstration, infants looked relatively longer at the object than at the model's face, with no difference in positive or negative displays. Infants during their second year of life thus capture the action-related referential specificity of others' emotional cues and seem to follow positive signals more readily when actively selecting which of two actions to reproduce preferentially.