Scientists are currently studying if impaired prediction is behind autism. The brain makes predictions. When someone laughs or smiles, our brain makes a prediction about the reason. For example, when someone is crying, we can predict that they may be hurt in some way. Impaired prediction is when the brain has the inability to make predictions about the world. Language deficits, repetitive behaviors, and sensitivities to stimuli may be an indication that the brain cannot predict what is going on in the outside world. Individuals with autism often line items or exhibit rigid behavior. This behavior may seem irregular to typically developing individuals, but for those on the spectrum they may be just trying to create order out of the chaos. The inability to predict leads to anxiety and other behaviors that manifest themselves in autism. Currently this is just a theory, and more research and experiments need to be conducted to prove the theory.

http://www.latimes.com/science/sciencenow/la-sci-sn-brain-prediction-autism-symptoms-20141006-story.html