ACS - your teacher who recognized this trait in your son sounds like a gem!
She was the best. In fact, when DS was in 5th, there was a half hour block of time when his teacher was doing remediation with the other kids and was worried that DS would be bored. Mrs.5, Mrs.K and DS came up with a plan whereby DS would go help Mrs.K with her kindergarteners for that half hour. He would work side by side with the teacher and her other (adult) aid and was treated like a peer by them and a big brother by the kindergarteners. He gained a lot of confidence and poise from that, and how he was treated. When DS graduated 5th, Mrs.K gave him the whole Harry Potter series in hard cover as a graduation present. It was a very special bond.
PS I'm not suggesting that having GT kids help other kids is always the right thing to do, but because of the relationship in this case, it was totally natural and a wonderful experience for everyone involved.