The power of smell in picking sex partners

Ladies, be honest: When it comes sexual attraction, how important is a guy’s smell? Not just his cologne or deodorant, but his natural scent? At Good in Bed, we believe that a woman should “follow her nose—it always knows.”

Research supports this idea: In two large studies led by Brown University olfactory expert Dr. Rachel Herz, women ranked a man’s scent as the most important feature for determining whether she would be sexually interested in him.

As it turns out, scent may be the main way in which women literally sniff out genetic compatibility with a potential mate. How we smell is an external expression of the genes that make up our immune system.

Like fingerprints, each of us has our own unique “odor print,”  which is part of a region of genes known as the major histocompatibility complex (MHC). Women prefer the scent of men whose MHCs are different from their own.

So when we say that opposites attract, we may not be talking about differences in personality, but rather differences in immune systems.  This is one of Nature’s ways of ensuring that we produce the healthiest offspring. No wonder that a woman’s sense of smell is at its peak when she’s ovulating and most likely to get pregnant.

In one study, a wide variety of men were each asked to wear the same T-shirt for two days in a row, after which the shirts were put into identical boxes. Various women were then asked to smell the shirts and to indicate which they thought would have the most sexually attractive wearers, based on the smell. The results showed that women were most attracted to men with an MHC most dissimilar from their own, while T-shirts worn by guys with similar MHC profiles tended to be rated as “fatherly” or “brotherly” but not sexually attractive. And in a survey conducted by the research firm Strategy One, 56 percent of women said they wouldn’t date a guy who smells like their dad.

So what about that cup of joe? Dr. Alan Hirsch, director of the Smell & Taste Treatment and Research Foundation, conducted research on behalf of AXE body products to determine women’s scent preferences in 10 different cities. “In each city we tested, women reported different scent preferences,” he says, “indicating that geography has a direct correlation to what scents women find attractive.”

Here are the scents that women found most preferable by region:

1.      New York – coffee

2.      Los Angeles – lavender

3.      Chicago – vanilla

4.      Houston – barbeque

5.      Atlanta – cherry

6.      Phoenix – eucalyptus

7.      Philadelphia – clean laundry

8.      Dallas – smoke/fireplace

9.      San Diego – suntan lotion/ocean

10.  Minneapolis-St. Paul – cut grass

I know what you’re thinking: Cut grass? Clean laundry? What the…?!

But there’s a science to these preferences. Scent can trigger powerful memories, especially from our childhoods, which is why these scents may still exert a hold on us years later. And according to Hirsch, “Research has shown that when women are in the presence of a preferred scent, they are more likely to project positive feelings on those around them, which can lead to increased attraction.”

While there is little to evidence to suggest that scent plays as powerful a role for men in sexual attraction, another study by  Hirsch found that the scents of lavender, pumpkin pie, donuts, and black licorice increased blood flow to the penis by nearly 40 Percent. And as I discuss in my book 52 Weeks of Amazing Sex,  “Certain scents increase oxygen in the brain, which in turn affects emotion, attitude, hormone levels, and energy. Both men and women respond positively to scents such as vanilla, black pepper and cinnamon. Other scents that are supposed to have libido-boosting qualities include frankincense, ginger, lavender, lime, orange, patchouli, and rose.”

So, enjoy that cup of coffee, mow the lawn, or fire up the grill—you never know what will happen!

Ian Kerner is a sexuality counselor and New York Times best-selling author, blogs on Thursdays on The Chart. Read more from him at his website, GoodInBed.