> This might work if you could get rid of the ability perceive race as a
> category altogether but just making the categories fluid wouldn't cut it.
> Discrimination could still be based one how close you fall to one of the
> ends of spectrum, e.g. someone is "too black." Anyway, I think this is a
> really goofy way of trying to fight discrimination, it goes after mental
> categories instead of dealing with the moral irresponsibility of being
> racist, sexist, anti-gay, that there is nothing justifiable about
> discriminating on the basis of the categories.
No, you're not getting it. It's about changing the social practices that make these categories important in society; it really isn't about altering mental categories. My point is simple: prejudice and discrimination require stable categories; thus prejudice and discrimination on the basis of some category can be eliminated by getting rid of the stable categories. You can say "X is morally irresponsible" and lecture them all you want, but if their world view justifies and/or requires prejudice against a group, your "let's all get along" strategy is a waste of time. Getting rid of the stable sexual categories (that's what I mean by fluid!) eliminates the problem.
> I don't think my point here precludes people having occasional sexual
> encounters outside what their sexual orientation biases them toward.
> What I think remains stable over a lifetime is our sexual attraction, that
> feature of puberty where physical arousal becomes associated with the
> opposite sex if straight or with the same sex if gay.
This claim isn't supported by data. The "stability" of sexual orientation is a product of a society that creates and normalizes stable sexual categories. Do a little historical and cross cultural research: this idea that a stable sexual attraction that emerges at puberty is not universal! You're falsely projecting the characteristics of the society you're familiar with onto human nature.
> But it is a puzzle if there is a negative effect on reproductive success, as
> there would appear to be for a trait that leads to near-exclusive homosexual
> behavior. Perhaps individual with this trait also ended up conferring some
> subtle positive effect on reproductive success in the original evolutionary
> environment (relative fertility, care-giving, protection) but so far an such
> effect hasn't been well zeroed in on.
Why assume "near exclusive homosexual behavior"? What we see in most primates and mammals are opportunistic homosexual encounters, not a stable homosexual "orientation" in a small percentage of the species. Why make humans the exception? If we assume that humans, like other primates, engage in a variety of sexual behaviors for various reasons--only one of which is reproduction!--then the mystery is solved. True, this requires giving up on the notion that stable sexual categories are natural and necessary, but as I've argued, we're better off without that notion anyway.
Miles