What was his upbringing like?
Was your DH an intellect always encouraging him?
Are you?
Maybe he is just very intelligent and feels uncomfortable around peers his own age as they are nowhere near as intelligent therefore they are alien to him.
I almost see it in one of my sons friends and they are 3.5!
X is very intelligent. He can read, write a bit, say and read the alphabet, count and read the numbers.
This boy and my son have been friends within a group of 6 since birth.
X clearly can't handle all the silliness when they are all together and seperates himself from all of them.
He doesn't jump about like a loon like the rest of them, he'd rather sit with books.
X also goes to the same nursery as my DS and he is described as a loner (sadly) by the teacher.
He can only play well with my DS as he is a good speaker and calmer (slightly) than the other kids. My DS can do NONE of the things X does though.
I don't find X strange or autistic. I see he is very intelligent and years ahead of his peers and I can imagine this will effect him and leave him confused as to where he fits in.
His mum was also so intelligent that she was given a scholarship to go to one of the best private schools in Edinburgh by age 12.
I imagine at 14, your son swings from 8-9 yrs old to an adult because he has never been able to 'find' himself in his own age group.