> <X> is part of the natural variation in how human brains work, and ... it's a category error to think of it as a malfunction to be repaired
No! No one is saying that everyone at one end of the spectrum has a disorder. It is specifically not a category error because the term "disorder" is not applied based on the variability, but rather based on whether the variation meaningfully disrupts the individual's life.
That's why the only change the author needs to make here is to say he has an attention deficit rather than saying he has a disorder.
