My son has some problems with Sensory Integration Disorder, which is a distant cousin of autism, and WDW has been very theraputic for him. His first trip was last summer when he was 3.5 and there were some things he could not do. His biggest problems were being in big crowds, so he could not do most of the shows because of this. He could, however, do almost any ride. He loved anything that moved, and he was tall enough to do Splash and Thunder Mtn. When we went back in January he was able to do so much that he couldn't just 5 months earlier. It was so cool to see how far he's come. For example, last summer he was terrified in the Playhouse Disney show. In January he enjoyed it and even jumped and danced along to some parts. Tears came to our eyes to see how far our baby had come. So even though he liked the Playhouse characters, at first he was not ready for that show. If you continue to take your son over the years it can really do him a world of good.