Pheromones: There Really Is Chemistry Between People
Did you ever meet someone and feel an immediate and irresistible attraction? Of course you have. So, how did you explain it? Was it the piercing eyes? The sexy accent? The sensuous lips? The gentle touch? Or was it simply "the chemistry?" After years of generally being relegated to the File 13 of scientific research, that ages-old answer now may be emerging as a powerful factor in explaining sexual attraction. Recent studies suggest that human beings - like other animals - produce, send out and respond to odorless substances called pheromones. And some researchers are looking into the theory that these substances may be the reason that you choose or reject a potential partner.
Pheromones have been documented to influence sexual behavior in animals - promoting attraction between male and female moths, snakes, monkeys, hamsters, and many other creatures. In these animals, pheromones are detected by the vomeronasal organ in the nasal cavity. Scientists now have uncovered evidence that humans may also have this ability.
In a study recently reported in Nature magazine, Martha K. McClintock and Kathleen Stern of the Department of Psychology at the University of Chicago found evidence that humans detect and are influenced by pheromones. They defined pheromones as "airborne chemical signals that are released by an individual into the environment and which affect the physiology and behavior of other members of the same species." The researchers have not yet delved into sexual attractiveness per se. Their method first sought to determine if pheromones do, indeed, exist in humans. To do so, they rubbed pads with sweat from the armpits of nine women beneath the noses of 20 other women. For two months, half the women inhaled sweat from women in the early phase of their menstrual cycle (pre-ovulation) and the other half from a later phase (during ovulation). Although the volunteers could not detect any odors, the results were significant: The menstrual cycles of the women who inhaled sweat from the early menstrual phase shortened by an average of 1.7 days a month. In some, it was shortened by as much as 14 days. Women who inhaled sweat from the later phase experienced a lengthening of their menstrual cycles by an average of 1.4 days a month. Some grew longer by as much as 12 days. Based on these results, the researchers concluded that there is strong evidence that human pheromones do exist. And this may explain why some women who live or work together report that their menstrual cycles tend to synchronize. Further research is under way to determine how pheromones influence behavior, including sexual attraction.
Other Sex-Scent Indications Although pheromones are odorless, other studies have been conducted on scents that can be detected. Alan R. Hirsch, MD, author of Scentsational Sex, conducted studies on both men and women to find out what specific scents caused sexual arousal. Hirsch, a neurologist, psychiatrist, and neurological director of the Smell and Taste Treatment and Research Foundation in Chicago, became interested in the connection between odors and sex when he observed that about 18 percent of patients who lose their sense of smell develop sexual dysfunction. He wondered if the inability to detect odors might have some direct connection with sexual response. To find out, Hirsch recruited 25 male medical students and used penile blood flow as a measure of arousal. Testing the students with different aromas, including perfumes, floral and food odors, Hirsch was astounded by his finding: "Much to our surprise," he writes, "...cinnamon buns caused greater changes in penile blood flow than any other odor." Realizing the results might only indicate that medical students are hungry, Hirsch conducted another study, this time with 31 men between the ages of 18 and 64. Using 30 scents and 46 test odors (some were combinations), his results were as follows:
* A combination of lavender and pumpkin pie showed the greatest measurable arousal, increasing penile blood flow by an average of 40 percent.
* Cinnamon buns were still popular, but not as much so. In combination with licorice and doughnuts, they finished second by increasing penile blood flow by 31.5 percent.
* A combination of pumpkin pie and doughnuts came in third, with an increase in penile blood flow of 20 percent.
* Among the least favored odors were cranberry and chocolate. Hirsch also found differences dependent on men's ages and characteristics. Older men liked vanilla better than younger men. Men who said they are having the best sex lives preferred strawberry. And men who said they have intercourse most frequently liked lavender, Oriental spice and cola. In fact, penile blood flow increased in response to every odor that was tested. That wasn't the case with women. Hirsch studied the sexual arousal of 30 women between 18 and 40 by measuring vaginal blood flow in response to a variety of odors. The study produced the following results:
* The preferred odor for women was Good & Plenty, a licorice candy, or a combination of Licorice Allsorts and cucumber, which caused a 13 percent increase in vaginal blood flow.
* A combination of lavender and pumpkin pie increased vaginal blood flow by 11 percent.
* Women had negative responses to several odors, including cherry, which caused an 18 percent reduction; charcoal barbecue smoke, which caused a 14 percent reduction. Interestingly, the study found that women aren't turned on by male colognes: They caused a 1 percent reduction in vaginal blood flow. No one knows exactly why men and women respond sexually as they do to scents like these. Perhaps certain odors remind us of happier, relaxing times or people we once knew - making us more receptive to sexual feelings. What do these studies mean for us? Should we throw out all our perfumes, scented soaps and colognes? Should we stop bathing and using deodorants so our natural scents can be detected? Should we be wearing our food in addition to eating it? Here are some suggestions:
* Experiment with scent. Have fun. For example, the next time you and your partner make love, have a bowl of fruit salad handy. Take a slice of strawberry, rub his lips with it and see how he responds. Caress her mouth with a piece of banana, allowing her to inhale its odor and see how she reacts. Try various essential oils, scented candles or massage lotions. Find out what you like and try to find a scent that turns on both of you.
* Hirsch suggests putting some pumpkin pie, cucumber or any other food you want in a blender and then pouring a few drops of the liquid in a test tube with a cotton ball on the bottom. It will last a few days, so you can inhale it many times. You also can put the liquid on your body or in your bath.
* Try giving up all scented products for two days. Many people find the natural smells of their sexual partners real turn-ons and are unhappy when these odors are washed away or covered up. Find out what your partner likes and see if you respond to each other's natural scents.
* Remember that as you grow older, your sense of smell tends to weaken. Since women have a keener sense of smell to begin with, older men may have more trouble detecting faint scents. But don't overdo it. Studies show that both sexes dislike strong odors. As Hirsch said, "If you're a woman and you want to induce male sexual arousal, start baking. And if you're a man and you want to induce female sexual arousal, throw away the cologne and buy some Good & Plenty." Olfactory signals, whether from naturally produced pheromones or from substances in our environment, apparently can be powerful tools when it comes to sexual arousal. Why, no one really knows. But this is known: Humans can detect between 10,000 and 30,000 different odors. Finding out which ones rev up your sexual engine might be worth grinding up a few pumpkins or cucumbers - or whatever.