Oh, so you're a {label}

(Originally posted by Pat in 3/2012)

I've noticed yet another failure mode of human reasoning, one which doesn't have a name as a standard bias or fallacy. I'm not sure what to call it: for the time being, perhaps we can go with “Label Fallacy”.
What is the Label Fallacy? It is when you think of a name for something, and then that by itself makes you think that you've understood it. You assign a label to something, and now you feel that you don't need to engage it any further; you get it now.
There's one very obvious example that should be salient to atheists: In theological arguments, “God” is almost always used as a label fallacy. What caused the universe to begin? “God.” Where does morality come from? “God.” These aren't answers—they tell us almost nothing—but they feel like answers to most people. They sate the hunger of curiosity without providing the food of knowledge.
There's another case that happens to me a lot, which is when the label fallacy is applied to me. “Oh, you're a constructivist.” “Oh, you're a classicist.” “Oh, you're an atheist.” “Oh, you're a liberal.” Then, the discussion ends; my interlocutor will hear no further arguments for my view, once my view has been labeled. The subtext in every case is: I have given your view a label, and therefore I have no further duty to engage with it. I must already understand everything there is to know about your view, for I have given it a name.
This is an easy trap to fall into, and I've probably done it myself with “Oh, you're a Christian.” or “Oh, you're a moral relativist.” or “Oh, you're a libertarian.” This is what we must train ourselves not to do. Once we know that someone is a Christian, we do know something about their ideas—we've narrowed the list of possible alternatives—but we don't know everything, for there are many different kinds of Christians, and some are far more reasonable than others. The label should be a beginning of discussion, not an end.
In fact, it may be that a problem as big as bigotry is partially founded upon the label fallacy: “Oh, you're a Jew.” “Oh, you're Black.” “Oh, you're gay.” Once you assign people a label, you feel that you understand them better, even if you really don't. Even if you don't know anything of real significance about that person you've just labeled a Jew, the mere fact that you can call them “Jew” and place them in that category makes you feel like you have understood them. (I don't think this explains bigotry by itself—there's too much else going on—but it may be an important part.)
Ask yourself: Do you tend to categorize people? Once you do, what do you use these categories for? Do you treat them as partial information, to be updated on later? Or, like most people, do you treat them as complete information, an end to inquiry? If the latter, you're guilty of the label fallacy.