Interacting effect of two social factors on 18-month-old infants' imitative behavior: Communicative cues and demonstrator presence.

Certain aspects of a demonstration have been shown to influence infants' interpretation of an observational situation and result in selective imitation. Studying social factors that trigger selective imitation may improve our understanding of how infants encode certain situations. However, only a few studies have investigated the possible interactions among these factors. In our study, 18-month-old infants (N=54) observed an adult demonstrator retrieve a toy from under an opaque ("baited") container by manipulating another transparent empty one. Infants were assigned to one of four conditions representing all combinations of two social factors: ostensive communication during demonstration (Communicative vs. Non-communicative) and presence of the demonstrator during reenactment (D-present vs. D-not present). Results suggest that infants' choice behavior was formed in two steps: during the demonstration and during the test phase. Furthermore, an interaction between the effects of the two levels was observed. Communication during the demonstration triggered imitative learning. Infants tended to copy the observed manipulation to learn the communicatively assigned way to reach the goal. This choice behavior was not influenced later by the presence or absence of the demonstrator. The non-communicative demonstration, however, did not elicit a particular learning mechanism. Therefore, in this situation, infants' choice behavior was affected by the demonstrator's presence or absence. Infants developed an individual solution and chose the baited container in the D-not present condition, indicative of emulation. In the D-present situation, they were more likely to reproduce the observed manipulation, which can be interpreted as a tendency to communicate with or conform to the demonstrator.