Most likely both ADD and divergent. The ADD meds have made a huge difference, and it definitely runs in the family. I wouldn’t say he asked a huge number of questions, but he was always very bright, very verbal and good with numbers. His intuitive understanding of things has often surprised us, whether mathematical or aspects of human nature. (He can also be quite oblivious to convention or human interaction). When he was about 3 or 4, he understood the concept of fractions, talking about half of a fourth and knowing what it was without knowing what it was called. He also talked about doing things in sets of 4. These days he gets frustrated sometimes because he’ll intuitively grasp a new concept in physics, but then struggle to understand the stepwise teaching that follows. He gets marked down on his math homework for not showing enough work. He’s definitely not a typical linear thinker, but then neither is the rest of the family.
It's not uncommon for extremely bright individuals to feel more comfortable with numbers and science, because they are predictable, constant, logical. People - quite simply - aren't.