Here is the difference,When my daughter was a toddler,she was very shy.At home, she would talk non stop.I would take her to work with me,and if a co-worker spoke to her,she would cling to my leg,bury her face,and not say a word,obviously knowing the person was trying to interact with her.When my son,who has autism, would go to work with me, and a co-worker tried to speak to him,he had no reaction at all.It was as if he couldn't hear them,and sometimes almost seemed like he didn't even see them.Like he looked right through them.In fact,having his hearing and eyes checked were things we had tested before we learned of his autism.So both kids wouldn't talk when I took them to work,but you see the difference?