Instapundit Glenn Reynolds has a long thread about interracial relationships. I don't know what the prevalence is in the States, but I know here in Costa Rica it's completely unexceptional. Four of my best friends here are in interracial marriages: one couple from the States (he's black, she's white) and another couple from Canada (he's white Irish, she's originally Trinidadian). Another great friend is mulato (his father was Afro-Cariibean, his mother is a dazzling blonde). Interracial marriages here are unremarkable (and hence barely even discussed). It's much the same situation in the south of England (and especially London), where as far as I know, something approaching 50%, maybe more, of relationships are now interracial.
I've dated girls in Costa Rica with skins every colour from Northern-European pale pink to very dark Dominican. And I'm 25% Irish, 25% Scottish and 50% English, so I guess that makes me the product of miscegenation right there.
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