Because I think fundamentally that is what really distinguishes the validity of these things. If you're good your good no matter what method you use as Jack alluded to in one of his posts.
Note: I think people are often good in spite of MBTT functions. They unconsciously redefine the terms in order to have them fit their analyses.* This isn't to say everyone who uses MBTT functions is good. Very few are.
*BlueWing actually described the INTP's "Fi" as some kind of odd Ti+Fe marriage, and this is the perfect example. It doesn't need to be like that.
That's where my buzzer went off. What do you mean by "incorrect"?
I'll preface my response by saying thumbs up to the level-headed discussion we're having in this iffy thread.
It means when you go through the effort of truly separating out behaviour (i.e. a kid with ADD with abnormal levels of neurochemicals vs. a kid who is attention starved due to parents, or going through a bratty phase because kids do that) the kids with genuine attention deficit can go through a fMRI and the scan will show different levels of neurochemicals that distinctly depart from the norm.
It's analogous to cancer, Jeffster: Every one of us has cancerous activity in our body; you do, I do, we all do. Some of it is natural due to aging, some of it is natural due to mutation happening once in a while, everyone has free radicalization of their molecular structures (aka cancer). We differentiate between any random person who has free radicalization and people who "have cancer" because there are physical differences that, after a point, the distinct departure from the norm in one's body becomes abnormal. I'm sure you can see just as easily as I do that with cancer, there are physical challenges that come after a point of not dealing with things.
With neurochemicals, these things happen in the brain; the brain is the control room for all behavioural activity. In the brain, also, there are challenges that come after a point of not dealing with things. This body location is the only difference.
We don't send every person who potentially has <insert neurochemical abnormality here> under the fMRI magnet because that's simply too costly. Way cheaper, way faster, way less effort to medicate people who are borderline. (I am not arguing in favour of medicating every kid that comes in one's path, I'm just stating reality--it's simply easier to medicate.)
(I'm not asserting that intervention like one-on-one helping a kid develop techniques to deal with their behavioural problem isn't beneficial--studies show it is helpful to a degree, and any help is better than no help. But if there's a significant physiological deviation from the norm, medicating an individual can throw their neurochemical balance into a healthy range that a) shows up healthy under the magnet under testing in studies (but, again, is simply too costly to do for non-life-threatening problems for the everyday IRL case) and b) helps their behaviour.)
The biggest problem with a term like "depression" is that everyone gets down in the dumps once in a while. We've all felt "depressed." Not all of us have had, excuse my language, really fucked up brain chemistry that leads to DSM-IV qualification of the term and had to deal with this. I can imagine what it's like to have a broken leg and have everyone tell you to "walk it off" and how invalidated I'd feel because I can't control the fact that my leg is broken and not properly functional. Then imagine that your brain chemistry is equally as incapicated, except not only are people telling you to "deal with it" but they don't even acknowledge that this physiological problem exists (because they can't see it physically). And the added bonus is that this invalidation is in your brain and it makes your mood even worse because you don't feel acknowledged and because your physiological brain makes up your thoughts and feelings. Telling a person who is DSM-IV certifiably depressed that they should "be happy" and "stop feeling so down" is like stepping on someone's broken leg.
*You don't have a soul. You are a Soul. You have a body.
*Faith is the art of holding on to things your reason once accepted, despite your changing moods.