I disagree. Mating is deeply biological phenomenon; the rational brain has little to do with it.
For example: I'm attracted to slim women. But some of my best friends are curvy. I'm not discriminating against curvy women; it's just that I find the skinny ones more attractive, without any rational reason for it.
I believe this is less biological than you think it is. You're attracted to slim women because there are a truckload of cultural artifacts celebrating slim women. If you were born 500 years ago, or in a different part of the world today, you may very well be attracted to curvy women.
And this is even more true for race - there may very well be people who are biologically wired to dislike certain skin colors, but IMO they are well into the minority. Race in dating has much more to do with cultural perceptions of race than any evolutionarily hard-wired perception.
In any case though:
> " it's just that I find the skinny ones more attractive, without any rational reason for it."
Which makes you, I guess the word would be... weightist?
The whole point of my post isn't to point at people and go "you monster! you won't date black people!", it's to point out that even subconsciously influenced racism is racism, and the net effect for the target individual is the same, regardless of if you're "simply like that without rational reason" or if you actively and consciously dislike them.
The fact that we've been programmed by culture and circumstance to discriminate against a certain group doesn't make it our fault, but it is still discrimination at the end of the day.
For example: I'm attracted to slim women. But some of my best friends are curvy. I'm not discriminating against curvy women; it's just that I find the skinny ones more attractive, without any rational reason for it.