11.78 Are very young infants more likely to imitate actions that are modeled by a person or simulated by an object? This question was the basis of a research study summarized in the article “The Role of Person and Object in Eliciting Early Imitation” (Journal of Experimental Child Psychology [1991]: 423– 433). One action examined was mouth opening. This action was modeled repeatedly by either a person or a doll, and the number of times that the infant imitated the behavior was recorded.

Twenty-seven infants participated, with 12 exposed to a human model and 15 exposed to the doll. Summary values are shown below.

Is there sufficient evidence to conclude that the mean number of imitations is higher for infants who watch a human model than for infants who watch a doll? Test the relevant hypotheses using a .01 significance level.

Person Model Doll Model x 5.14 3.46 s 1.60 1.30