I mostly agree with HK. That's an outstanding social ability, so long as it doesn't come across as fake or forced. One concern I'd have would be if the child is pretending to like things you know they don't, or the opposite. Being able to relate to people like you're one of them is fine, but pretending to be someone you're not is harmful in the long run.
Likewise, I'd be very, very, very worried if this child displays a tendency to follow the crowd into things they know are a bad idea. Pliability to peer pressure early on just leads to getting in trouble, but that's the time to head it off, because it leads to really bad places in the teen years.
As for teachers... get him tested, and present the data.
