Gay Men Respond Differently to Pheromones

From Yahoo! News:

The study, published in Tuesday's issue of Proceedings of the National Academy of Sciences, was done by researchers at the Karolinska Institute in Stockholm, Sweden.

They exposed heterosexual men and women and homosexual men to chemicals derived from male and female sex hormones.

These chemicals are thought to be pheromones — molecules known to trigger responses such as defense and sex in many animals.

Whether humans respond to pheromones has been debated, although in 2000 American researchers reported finding a gene that they believe directs a human pheromone receptor in the nose.

The Swedish study was one of a series looking at whether parts of the brain involved in reproduction differ in response to odors and pheromones, lead researcher Ivanka Savic said.

The brains of different groups responded similarly to ordinary odors such as lavender, but differed in their response to the chemicals thought to be pheromones, Savic said.

The homosexual men's brains responded more like those of women when the men sniffed a chemical from the male hormone testosterone.

Savic said the group is also doing a study involving homosexual women but those results are not yet complete.

"It is one more piece of evidence ... that is showing that sexual orientation is not all learned," said Sandra Witelson, an expert on brain anatomy and sexual orientation at the Michael G. DeGroote School of Medicine at McMaster University in Ontario, Canada.

Take that, you people that think I chose to be gay.