Women's perfume laced with synthetic pheromones acts as a sexual magnet and increases the sexual attractiveness of women to men, San Francisco State University researchers conclude in a study appearing in the current issue of the quarterly journal Physiology and Behavior. The study, the first of its kind to independently test a sex attractant pheromone for women, showed that of the 36 women tested, 74 percent of those wearing their regular perfume with the pheromone saw an overall increase in three or more of the following sociosexual behaviors: frequency of kissing, heavy petting and affection, sexual intercourse, sleeping next to their partner, and formal dates with men.
In contrast, only 23 percent of the women who had a placebo added to their perfume saw an increase in these sociosexual behaviors. Researchers conclude from these data that the pheromone users were more sexually attractive to men.
"This is a biological signal to a man that suggests that this woman can reproduce and he responds with romantic behavior related to securing intimate relations with her," said research author Norma McCoy, an SFSU psychology professor. "This is not a smell one can detect, neither the man nor the woman is aware of it, but it's very powerful. This chemical appears to influence a man's desire to have sexual intercourse." McCoy, a member of the International Academy of Sex Research, has spent more than 20 years studying female sexuality. In 1995 McCoy researched the role oral contraceptives play in suppressing women's sexual interest. To her surprise, the well-publicized study revealed that some oral contraceptives instead enhanced a woman's libido.
In the pheromone study, one woman reported she engaged in kissing and petting about one day a week before taking part in the experiment. However, after wearing the pheromone, the number increased to nearly six times a week. The woman also reported she slept next to a romantic partner and engaged in sexual intercourse four nights a week while wearing the pheromone compared to less than one night a week when she did not wear the pheromone.
Pheromones are chemical substances secreted externally to cause a change in the reproductive behavior of another person and can directly stimulate a man's sexual behavior through olfactory sensors processing information. Either the olfactory epithelium or the vomeronasal organ, which is located in the nose and conveys messages to the higher cortical regions of the brain, potentially could mediate pheromone signals.
However, SFSU researchers hypothesize that the olfactory epithelium is the most likely site. Lisa Pitino, a graduate student in psychology, conducted this research with McCoy in fulfillment of the thesis requirement for her master's degree.
"I've always been interested in subconscious signals between men and women and how they can affect sexual chemistry," said Pitino. "This was an opportunity for me to study this phenomenon scientifically."
The study was conducted for 14 weeks in 2000. Thirty-six women were recruited on campus through psychology and human sexuality classes and asked to participate in an experiment described as testing a pheromone that would "increase romance in their lives." The criteria for participation called for women who were heterosexual, regularly menstruating, neither married nor co-habiting with a man, not currently using an oral contraceptive and in good health.
Women between the ages of 19 and 48 took part in the study. The ethnic backgrounds of the women were white, Filipina, Latina, Portugese, Chinese, Brazilian, Native American, Mexican, Japanese, Jewish and Hispanic.
The women first recorded baseline information everyday for two weeks on seven sociosexual behaviors: petting/affection/kissing; sleeping next to a romantic partner; sexual intercourse; formal dates; informal dates; the number of times a man approached her; and masturbation. The women then selected vials that were clear, odorless and identical in appearance. The contents of the vial - the synthetic pheromone or the placebo - were added to two ounces of the woman's perfume. Each woman applied two to three dabs of the perfume under her nose, on her cheeks and behind her ears at least every other day. The women used 34 different fragrances.
A total of 19 women wore the pheromones and 17 women used the placebos. During three consecutive menstrual cycles, each woman recorded seven different sociosexual behaviors each day. Overall there were no significant changes observed between the two groups in the categories of informal dates, the number of times a male approached the woman and masturbation. Only the intimate behaviors that required a partner were affected. Significant results were experienced after one menstrual cycle and the effects were increased during the second cycle.
