Women’s Nonverbal Scent During High Fertility – Men Rate Women’s Odor As More Attractive At Ovulation
Researchers led by Kelly Gildersleeve, Department of Psychology, University of California, has found evidence that women emit odors that are more pleasant, sexy and intense at around the time of peek fertility.
Forty one women provided samples for the study. Each did not use hormonal contraceptives of any kind and were none smokers to prevent any scent contamination. Eighteen to sixteen days prior to their predicted next day of menstruation (that is 1 to 3 days prior to their predicted ovulation) scent collection occurred as well as 10 days prior to their predicted date of next menstrual onset. The first sample was the high fertility sample and the later, the low fertility sample. These collection times were confirmed through a Clearblue ovulation test which is found to be 97% accurate in detecting ovulation.
To collect the samples, women were instructed to tape cotton gauze pads in both underarms for a period of 24 h. Researchers demonstrated the procedure to ensure that the pads made direct contact with the underarm skin.
The subjects also followed a strict odor program including a “wash-out” phase including showering with unscented soap, washing bed sheets with fragrance-free detergent, and avoiding perfumes, deodorants or antiperspirants as well as not eating pungent foods including garlic, asparagus or pepperoni, drinking alcohol, using tobacco or recreational drugs, spending time in rooms filled with strong odors including smoke or incense and engaging in sexual activity with another person.
One hundred twelve men were recruited as scent raters.
Results revealed that men were able to discriminate between the high and low fertile samples above the rate of chance. The majority of the men preferred the high versus low fertility samples (61%).
Interestingly, the women who were least likely to contaminate their odor sample were rated as most attractive during in their low fertility sample. In other words, contamination of normal human body odor reduces its overall attractiveness.
In addition, the women whose scent samples were least likely to be contaminated by non-human odors and of which were closest to women’s high-fertility were rated as most attractive in terms of scent (56%).
“In other words,” say the researchers “women who collected their high-fertility scent samples closest to the day of ovulation tended to receive the highest attractiveness ratings at high relative to low fertility.”
When samples were provided pair wise, and men could compare one scent to another, they were more likely to rate the high fertile scent as attractive versus the low fertile scent.
Overall, the results suggest that men are sensitive to fertility cues and that these are carried, amongst other things, by women’s scent.
“Several studies have shown that women in heterosexual relationships report that their partners are more loving and attentive, jealous and proprietary, vigilant of their activities, and monopolizing of their time near ovulation as compared with less fertile days of the ovulatory cycle,” say the researchers.
This suggests that men are picking up on the nonverbal odor cues of their partners which is mediating their behaviour.
Other research has found that men’s testosterone levels rise in response to high, but not low fertility samples. This suggests that men may react hormonally to sexual odors which primes them to behave in ways conducive to soliciting sexual attention from ovulating women.
Future research, say the experimenters will measure changes between partners with respect to menstrual cycle to see if there are any behavioural changes such as increased sexual intercourse. They surmise that men who are regularly exposed to their partners scent may be best able to detect impending changes and respond accordingly.
“For example, men who regularly have sex or cosleep with their female romantic partners or whose partners do not engage in practices that mask their natural body scents may experience greater exposure to and hence more opportunities to detect and respond to scent cues of fertility than do other men,” say the researchers.
Image Credit: Ish Frost
Gildersleeve, Kelly A.; Martie G. Haselton; Christina M. Larson and Elizabeth G. Pillsworth. Body Odor Attractiveness as a Cue of Impending Ovulation in Women: Evidence from a Study Using Hormone-Confirmed Ovulation. Hormones and Behavior. 2012. 61: 157-166.