The Biology of Attraction

You might be thinking that you need information about attraction as much as you need a hole in the heart. That’s because you already know what you like in a mate—be it in body parts, in personality traits, or in styles of facial hair. While it’s true that you and your senses can be attracted to many different people and be repulsed by as many others, there is some science to the process of finding the perfect mate. How? With the body part that gets about as much sexual attention as the popliteal fossa: your nose. While your initial attraction to someone may be physical, one of the true messengers of love is chemical. We’re attracted to people who have good smells (like flowers) and repulsed by those who have bad smells (like Dumpsters). Though we tend to spend a lot of time and money disguising our smells with perfume, deodorant, shampoo, and detergents, our brain helps us cut through all that gunk to. That’s the squishy area behind the knee. We’d venture to guess that while probably uncommon, there surely are a few people out there who do have a fossa fetish and can detect the unique smells of different people.

Now, we’re not talking about the kinds of major odors that should send you straight to the bath; we’re talking about microsmells—called pheromones—that are like dog whistles of the body. They’re so subtle that you can’t detect them consciously, but they’re powerful enough to influence decisions about attraction. Pheromones—sometimes odorless steroids that can be detected at picogram concentration (that’s one-trillionth of a gram, sort of like a single molecule dancing along)—float through the air and stimulate nerves in your nose. The nerve signals are carried to your brain and trigger complicated chemical reactions that ultimately end with a question such as “Can I buy you a drink?” (They’re also important because they help animals distinguish one another—so that father doesn’t breed with daughter and thus increase the chance of genetic mutations.)

In the past five years, scientists have become extremely interested in this "accessory olfactory system"—that is, it’s just starting to be understood, which causes some skepticism in scientific circles. But this is how the theory goes: The pheromone system starts with nerve cells in a pair of tiny, cigar-shaped sacs called the vomeronasal organ (VNO), where the signals are first picked up. Located just behind the nostrils in the nose’s dividing wall, the VNO is a pretty primitive structure. The nerve fiber attached to these organs—specifically called cranial nerve zero because all the other numbers were already taken before it was discovered—responds specifically to scents from potential mates. Nerve zero begins in the nose and ends in the brain area that deals with sex. Because this nerve is important in the sex drive of other animals, people theorize that it plays a big role in our sex drive, too. Why? Pheromones and testosterone both seem to be direct drivers of sexual desire and activity in long-term relationships. Even after we find a mate, we can respond to all kinds of pheromones from different people; some attract us and some repel us. Some research even indicates that specific pheromones applied to the skin increase the amount of sex we have.

This material came to you from YOU: Being Beautiful, by Michael F. Roizen, M.D., and Mehmet C. Oz, M.D.