It's a question that has sparked controversy over the years. Are people born gay, or does something in their environment cause them to become gay? A new study may lead to some answers.
The study suggests there may be a biological basis for one's sexual preference, and for some members of the gay community, the news does not come as much of a shock.
"I'm not surprised that they're finding data to show biological basis, because a lot of behaviors have biological basis," says Gay Rights Activist Ellen Bass. "You know, just like people are left handed and so they prefer to write with their left hand."
The study, which used a brain imaging technique, showed the brains of women and homosexual men responding similarly to odors produced by straight men.
The new research is leading some to believe that sexual attraction is indeed a matter of chemistry, more specifically hormone-like chemicals called pheromones that are secreted through the skin and other parts of the body.
Dr. Barbara Bartlik with the Weill Cornell Medical Center says the medical community has "known for a long time that pheromones play an important role in animal courtship and they also play a role in human mating behavior."
"For a lot of people, including myself, being gay feels right, and there probably is a biological basis," says Bass.
Even though the study does not prove a biological basis for homosexuality, the new findings lead some in the gay community to believe it's just a matter of time until homosexuality is better understood and more widely accepted.
"Some people like chocolate and some people like vanilla," says Bass. "Some people are gay and some people aren't, it's just how we are, and the more people that see that, perhaps society will evolve to the point where being gay doesn't matter at all."
The study was released by the Proceeding of the National Academy of Sciences.