Imitation Deficits in Children with Autism Spectrum Disorder: How Relevant Is Social Motivation?

Background: Children with autism spectrum disorder (ASD) display significant deficits in imitation. The presence of these deficits may be explained in part by impaired social motivation. That is, typically developed (TD) children imitate not only to learn something but imitate also in order to satisfy the social motivation to affiliate with others. Especially, one indicator of social motivation is when children imitate the exact actions of a demonstrator even when the actions are unnecessary to achieve a goal. According to one view, children do this out of a wish to socially engage with the demonstrator. As children with ASD exhibit significant impairment in social communication, the social interaction that occurs may not be sufficiently motivating for children to engage in imitative behavior. So far, however, little research has been devoted to examine the relation between social motivation and imitation deficits in ASD compared to TD children.

Objectives: We sought to answer two broad questions: (1) What is the role of social factors in motivating imitation in TD children? (2) Is there evidence suggesting an association between imitation deficits and impaired social motivation drive in children with ASD compared to TD children?

Methods: To address (1) data of 66 TD children (M = 18 months 22 days; SD = 33 days) are reported. It was assessed whether TD children’s imitation behavior of unnecessary actions to achieve a goal differs upon an interactive and social play period versus a non-interactive and non-social play period with the model prior to the imitation task. To address (2) data of 20 TD children (Developmental age in months: M =28; SD= 9,88) and of 20 children with ASD (M= 32; SD = 9,70) are reported. It was assessed how TD children and children with ASD imitate necessary actions compared to unnecessary actions to achieve a goal

Results: Results regarding (1) demonstrated that TD children profit from a model’s social behavior compared to a non-social behavior in a prior play period: TD children in the social condition (M = 1.42, SD = .77) showed a significantly higher imitation rate of unnecessary actions than children in the non-social condition (M = .68, SD = .82), t(36) = -2.858, p = .007. Results regarding (2) demonstrated that children with ASD (M=3.90, SD=2.03) and TD children (M= 4.05, SD= 1.40) showed no difference in imitation rate of necessary actions, F(1, 38) = .13, p = .719. However, TD children (M =2.05, SD=2.21) showed a significantly higher imitation rate of unnecessary actions than children with ASD (M = 3.45, SD=1.54), F(1, 38) = 5.40, p = .026.

Conclusions: First, the results provide evidence that TD children are motivated by social interactions and that this motivation influences imitation. Second, as children with ASD show a diminished inclination to imitate unnecessary actions, the present results give some further insight that decreased social motivation in children with ASD can explain deficits in imitation. The findings underline the importance of therapies to incorporate social skills while focusing on improving imitation in children with ASD.