Interesting discussion. I have a friend with a 3.5 year old DD who currently has her on a gluten/dairy free diet (and yes - costs a fortune!) for borderline autistic behaviors. It's hard to say what is going on with her. She definitely prefers to play alone and have her own space. She seems probably at least MG. But she likes me a lot! It takes her a long time to get to trust people. My DD4 and her don't play together at all, and my DD really loves to play with other kids.