My husband and I have decided to add another bundle of joy to our family. Our son will be 4 in April and he is high functioning autistic. We have been trying to explain things to him about becoming a big brother the best we can. His speech and vocabulary have been blossoming lately, and his development has taken off. We are a little nervous on how he would react to the new addition, would any of you have any advice on how to help him with this transition? I've considered getting him a babydoll to try to show him how to treat a little one..