What the Nose Knows A recent study in Sweden revealed that how one responds to human pheromones is affected by one’s sexual orientation. While gay and straight men responded differently to male and female pheromones, gay men and straight women had a similar response. The media leapt on the story, as it inexplicably does whenever a biological link to homosexuality turns up. Actually, the scientific importance of the paper was its confirmation of the very existence of pheromones in humans, which until recently was in doubt. Only in 2000 was it shown conclusively—as indicated by brain imaging that tracks blood flow to different regions—that heterosexual men and women respond differently to male and female scents. What the new study showed is that pheromones are in fact related to sexual attraction, since it is the object of desire that gay men and straight women have in common. And while it cannot answer the age-old question of whether being gay is genetic, the finding skewers the notion that one’s sexual orientation is somehow “chosen.”