Swedish scientists have again unearthed evidence indicating homosexuality's biological. After isolating male and female pheromones, the researchers requested straight men, straight women and lesbians do a sniff test. And the results are eye-opening:

Lesbians' brains react differently to sex hormones than those of heterosexual women, new research indicates.
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Lesbians' brains reacted somewhat, though not completely, like those of heterosexual men… Heterosexual women found the male and female pheromones about equally pleasant, while straight men and lesbians liked the female pheromone more than the male one. Men and lesbians also found the male hormone more irritating than the female one, while straight women were more likely to be irritated by the female hormone than the male one.

The same group of Swedes discovered similar links between gay men and straight women last year.