Defining this real variation as disordered seems a fundamental problem. This has been recognized in medicine and mental health for so long that I don't know if

Defining this real variation as disordered seems a fundamental problem. This has been recognized in medicine and mental health for so long that I don't know if you could find someone still practicing who wasn't taught it in school. If you go to a mental health care provider and tell them that your family thinks you have a disorder because you prefer not to socialize and get everything you need delivered so you don't need to leave the house again after work, they're going to ask you if you're unhappy about it or if you feel your life is diminished in some way by an inability to leave the house when you want to. If your kid has six fingers, a doctor's concern will be whether all the fingers are developing in a healthy way or one needs to be removed because it isn't functional and will be a source of pain and injury. The principle hasn't been a panacea for prejudice, of course, notably in the case of homosexuality, but difference itself is not automatically treated as pathology in the absence of social prejudice. Doctors aren't treating people for having red hair or 20/10 vision or thinking stamp collecting is fascinating.