Question: Are certain characteristics present in all children with an autism spectrum disorder, and are some characteristics very unique to autism?
Answer: Well, no two children with autistic spectrum disorders have the exact same symptoms. The severity of the core deficits can vary greatly from one child to the next. But one of the universal deficits that's shared by all children with autistic spectrum disorders is a deficit in social relatedness -- the desire, the inherent desire to want to connect with others and want to share with others.
And early on that presents as a deficit in joint attention -- the behaviors that infants demonstrate to want to share their environment or their world with others.