I agree with pulp_fiction's answerwith pulp_fiction's answer - this kid is just a very introverted individual. Don't panic.
Try to offer him lots of opportunities to socialize, but do it on his terms. He like science and math? What about clubs or camps. Take him to a meetup at the Smithsonian.
Another question is does he like to game? He kind of sounds like a gamer. Try taking him to a comic book shop or playing some board games with him. Intelligent individuals love strategy, its a great mind exercise. This could be a great way for you two to connect without worrying about what to talk about.
I highly suggest Star Realms and Lords of Waterdeep, they are really hot right now and a lot of fun to play.