Do Humans Sense Pheromones?
The best evidence that humans communicate through pheromones comes from Martha McClintock, who in 1998 completed a study in which she manipulated the timing of women s menstrual cycles. Every day for two months, she and Kathleen Stern of the University of Chicago collected cotton pads from the armpits of nine women in various phases of their ovulatory cycles and then wiped these pads just under the noses of 20 other women, who were asked not to wash their faces for the next 6 hours. The recipients did not know the source of the compounds and could smell only the alcohol, which served both as a control and as a carrier of the compound. Women who had been exposed to pads from women in the follicular phase (before ovulation) ovulated earlier, shortening their menstrual cycles. However, pads taken from the same donors during their time of ovulation had the opposite effect, delaying the recipients ovulation and lengthening their menstrual cycles. “This study provides definitive evidence of
