The Appropriateness of Adjectival Nouns

Ok, so this is probably a slightly different subject from what many of my other posts will be, but I'm a huge linguistics nerd too, so I thought I'd kick it off with this, based on a discussion a few of us had a couple weeks ago.

So here's the main question: Is calling someone an "[adjective]" as a noun versus an "[adjective] person," inherently offensive labeling, or is this usage somewhat an accident of language? For example, we can all pretty much agree that calling someone a "schizophrenic" versus "a schizophrenic person" or "person with schizophrenia," is offensive, but is it always the case?

First, there's the issue of whether labeling someone is inherently problematic. Clearly, labeling someone as a "schizophrenic" or a "felon" brings a attribute forward as central to the identity of that person, regardless of whether the person views himself in that fashion. And those are just the examples that are grammatically correct - these days calling people "a black" or "a transgender" just sounds weird, for example. However, there are clear examples of descriptive nouns that can be adequately and properly used. I remember back in Hebrew School, I was asked whether I felt I was an American Jew or a Jewish American - it was a question in the context of Jews in the diaspora but the obvious assumption is that I should be comfortable being "a Jew" or "an American" rather than "a Jewish person" or "an American person." Could religion and nationality be acceptable labels, but race, gender identity, mental disability, and felony status not be?

We could posit that it's a question of negative perception - that centering a person's external identity on a phrase with negative connotation is too marginalizing. But I'm not sure that answers the whole picture. For example, in many parts of the world "Jew" is indeed a slur, but I don't feel like it would be linguistically improper. If I travel to Jordan, am I suddenly a "Jewish person" rather than a "Jew?" However, some people would say "a black" or "a gay"in this country - is the bigotry why we say that's wrong? I'm just not sure it's that simple.

Maybe we can look to self-identification. We could think of the previous argument as predicted self-identification, but now we're asking about actual. Transgender people and genderqueer people do this with pronouns - there is no standard, but you call people what they're comfortable with. However, this doesn't seem workable as a general rule for adjective versus noun because a) we're more likely to be talking about an abstract "black person" and b) gender nouns and pronouns are weird in that we have no corresponding adjectives (e.g. woman, but no "womanish person"). We have enough trouble with he/she when we don't know the gender for whatever reason - to turn that confusion on all of language would just be unworkable.

Is it the fact of an unmodified adjective (i.e. "a Jew" versus "Jewish")? Well, no - "American" contradicts that, for one. And clearly as a linguistic matter, sometimes the unaltered adjective becomes an acceptable formal noun - take "homosexual" for example.

In the end, I think it's mostly a question of linguistic accident, rather than just the inappropriateness of labels. There is just no linguistic principle to follow - too many contradictions. "A black" is not ok, but "African-American" is. How about "Hispanic" and "Latino/a?" The social context seems to have little to do with those distinctions. Same for "gay" and "lesbian." Why is lesbian essentially a noun, but gay is not? How about plurals? "The gays" seems acceptable to some, and at least linguistically more comfortable. And then what about "American" vs. "French/Frenchman/French person?"

Now, to say that it's linguistic accident doesn't mean we can really disregard the rules and call people whatever we want. Language matters and is too powerful to ignore. And as far as self-identity, once a person expresses a preference, that trumps all (all my Caribbean friends saying they're black, not African- American comes to mind). But what it does mean is that we just have learn what is acceptable and be sensitive to the possibility that acceptable usage will change because there are no clear linguistic rules. Given that's what we already do, into shouldn't be too hard, right?