We say so blithely that children learn by copying, but a recent study comparing autistic children and normally-developing ones shows there’s more to this than is obvious.
The study, involving 31 children with ASD, 30 typically developing children matched for language skills, and 30 typically developing age-matched children, had the children watch an adult model how to perform a simple action. The demonstration included two vital actions and one superfluous action. The child was then asked to undertake the same task (without mentioning any need to copy all of the actions of the adult exactly as they had seen them).
Almost all children (97%) successfully managed the task, but while typical children copied 43-57% of the unnecessary actions, autistic children copied only 22%. This despite the fact that, when shown the demonstration again and asked to judge whether each action was “sensible” or “silly,” the children (and especially typical children) had no trouble recognizing the unnecessary actions as silly.
In other words, it’s not about reasoning ability, it’s about social motivation. Typical children want to please adults and ‘fit in’, so they copy even the silly actions. Autistic children care less about this.
The findings point to the social nature of copying behavior — it’s not simply about learning.
 . Children with autism do not overimitate. Current Biology [Internet]. 2013 ;23(7):R266 - R268. Available from: http://www.cell.com/current-biology/abstract/S0960-9822(13)00207-8