Social competence and person-object differentiation: An analysis of the still-face effect.

The communicative abilities of infants, revealed in the still-face (SF) procedure, were examined in 2 studies comparing behavior toward people and «interactive» objects. In Experiment 1, thirty-two 3- and 6-month-olds were presented with an object and a person (mother or female stranger). The SF effect was produced only by mothers and strangers. Positive affect clearly established person-object differentiation; infants smiled at people but rarely at the object. In Experiment 2, twelve 3-month-olds were presented with 4 stimuli: a female stranger and 3 objects with features varying in similarity to an abstract, smiling face. Again, infants reseerved their smiles for the person