My oldest son has PDD-NOS and we just had a referral put in for my 14 month old for an EI eval. It was noted by my 2 year old's therapist that the baby does a W sit. He actually does this all the time and I never knew that it was a problem. Does anyone else know anything about this? Is there a link between W sitting and autism? Any advice on the topic is appreciated as I am concerned about his motor development and possible speech delays.