Depending on his age, it's hard to get an average read. When DD8 was 3 her pediatrician recommended testing. She was very shy and didn't talk a whole lot. Her score was not GT. At seven she was administered the WISCIV and tested at 148 which I'm told is a not common score on that test.
I think it's common especially for HG(+) to be frustrated with same age peers. Also, at a young age they don't seem to have those insights that would allow them to keep their comments to themselves, I think it's a good idea to get involved and try to discourage this behavior from becoming a solid habit.
There was a period of time when I had to watch DD6 100% of the time during playdates, so I could interrupt her each time she said or did something that would be considered socially unnacceptable and bring it to her attention. I would gently ask her to step away and calmly explain in age appropriate way why it was not okay and how the other child may react/feel. It seemed I did this over and over and over and over....etc....
It's an ongoing process but has gotten much better.
If you have a child psychologist who works with GT, perhaps you can recruit that person to help you.
Good luck
