Lesbian women respond to certain natural human scents differently than heterosexual women do, a study has found. But lesbian responses aren’t quite like those of heterosexual men.
Ivanka Savic of the Stockholm Brain Institute in Sweden and colleagues conducted the research, which focused on substances called pheromones. These are chemicals released by animals that change the physiology or activities of other animals of the same species.
Pheromones are common among animals, but research into possible human pheromones is in its infancy. Scientists long believed humans didn’t respond to such substances, but that has begun to change.
A year ago, Savic and colleagues reported that the brains of gay men react similarly to those of women, and differently from those of other men, to the smell of a chemical in male sweat. They also found, previously, that homosexual men and heterosexual women activated the same brain region, called the anterior hypothalamus, in response to a possible sexual pheromone called AND. The substance is a derivative of the hormone progesterone.
In contrast, they said, heterosexual men activated their hypothalamus in response to a potential female pheromone known as EST.
In the new study, they examined the brain activity of 12 lesbian women. Surprisingly, they said, unlike the other study groups, lesbians responded to both pheromone-like compounds in a similar way.
Moreover, they added, while lesbian women processed these compounds in a pattern more similar to heterosexual men than heterosexual women, the relationship to the opposite sex was not as strong as it was between homosexual men and heterosexual women.
The results further support the idea that both chemicals are pheromones involved in sexual preference, Savic and colleagues said. The findings also suggest male homosexuality is quite different than female homosexuality, they added.