I know a lot of people with IQs that are 4 standard deviations above the mean, and there's a lot of variety there. They're on a "different level" in a lot of different ways. It's not always obvious they're brilliant, and besides, some of them feel safer keeping it hidden. Their otherness often shows up in quiet ways that usually go unnoticed. Math prodigies (and programming gurus) are easy to spot, but other forms can be quite subtle. So your son may surprise you yet. (A father's opinion is crucial, so I hope your assessment of him doesn't come across as disappointment. You don't want him to be telling himself he's not really a genius, because he might start believing it. Tell him to let his freak flag fly!)