Your Pheromones are so hot: A Study of Sexual Attraction

It’s unlikely that pheromones will ever be used in a pick-up line; however, scientific research has shown that pheromones could play a part in human sexual attraction.  Since the 1980s, when pheromones were discovered to exist in humans, numerous perfume companies have launched marketing ploys to sell people “magic” scents to improve their sex lives.  There is much debate about the potency of pheromones in human relationships, but pheromone research has lead scientists to question our independence in mate selection.  It has also spurred questions about the difference between consciousness and unconsciousness.  How much can we actually control?  That is the question.

            Decades ago, pheromones were detected in silkworms for the process of sexual attraction. A compound extracted from a specific gland in the female silkworm caused the male silkworm to perform a mating dance.[1]  It was at this point that scientists began to realize the importance of scents in sexual attraction.  Various experiments were done involving insects, mice, dogs, and monkeys.  In all of these situations, when male subjects were presented secretions from a woman (whether or not they emitted an odor), they were more attracted to the female subject.

            Experiments involving animals seemed to prove the existence of pheromones, and that prompted the capitalistic venture to bank on sexual desires.  However, pheromones in animals do not prove the existence of pheromones in humans.  Although many varieties of animals have/use pheromones (amphibians, reptiles, mammals), there is no proof that humans do. Pheromones appear to be processed though an olfactory section called the vomeronasal organ (VNO). [2] Thus, many scientists have concluded that as long as there is a VNO, there is the possibility of pheromones.  The part that provides complication is that the human VNO has yet to be found.  All that has been discovered are “two small pits on either side of the nasal septum that fit the description of openings to the VNO.” [3] If these pits don’t lead to the VNO perhaps pheromones can be processed through another system?  Perhaps the VNO will be found soon?

Pheromones, when received, should cause a behavioral or physiological response.[4]  These responses are obviously occurring in the animals.  However, it’s difficult to determine how these responses are being elicited.  In order to determine if animals and humans use the same method for mating (pheromones), one needs to know if animals and humans are processing inputs in the same manner.  This is difficult to figure out because first-hand accounts of mating cannot be attained from animals.  Researchers have no way to know if animals understand that they are receiving pheromones.  While a discussion of human consciousness versus unconsciousness is a debate unto itself, it would be interesting to discover if pheromones are being received consciously by other creatures.  In the case of certain animals (such as elephants, which perform a ritual involving the urine of female elephants), pheromones appear to be used more consciously.[5]  Why don’t humans respond in this way?  I wonder if the presence of the I-function is necessary for activation of the pheromones.

Unconscious systems work to synchronize women’s menstrual cycles, and thus, it should not be doubted that other systems are at work without our conscious selves being aware of it. In fact, possible pheromonal influences on menstruation are what prompted scientists to look for other pheromones in humans. As it turns out, “the exchange of two different pheromone signals between female rats can produce ovarian synchrony.”[6]  This explains why female roommates often cycle together.  The interesting part (which supports the presence of pheromones) is that this synchronization process is done without the knowledge of the woman herself.  She doesn’t decide that she would like to cycle with another woman, this is decided for her unconsciously.  Based on experiments with rats and humans, it has been concluded that pheromones are responsible for the cycling.  In the rats, certain signals lengthened the estrogen cycle, while other signals shortened it.[7]  If outside sources can affect something as personal as a menstrual cycle, there is no reason to doubt that other parts of our bodies cannot be controlled.

There has been research showing that pheromones could used to reveal immunity deficiencies in potential partners.  Since no one wants to reproduce with an ill partner, this could be used as a tool for natural selection.  According to experiments involving beetles, the female beetles preferred males with the lowest asymmetry and parasite burden.[8]  This bodes well for the theory that pheromones have a place in Darwinian natural selection.  However, invertebrates appear to not have such an adaptive immune response system.[9]  While these experiments once again prove the existence of pheromones in other creatures, they do no prove their existence in humans.  However, if pheromones were to be discovered, we would know that pheromones can be used not only for sexual attraction, but also for partner choice and natural selection.  By giving pheromones an evolutionary advantage, their existence in humans is made more probable because the human body is not likely to eliminate something that would aid it in survival.

Do humans have pheromones or not?  It’s difficult to say.  However, operating on the assumption that we do (because so many other creatures utilize them successfully), where are these pheromones located?  How do humans use them?  Given the ability of female humans to synchronize their menstrual cycles, it’s safe to assume that we use odor communication in at least one way.  As Erik Filsinger writes, “Sex pheromones could still exist.  It would make sense for a non-conscious process to take over the task of increasing the likelihood of sexual activity at fertile times.”[10]  Here is another point in favor of natural selection.  Human error is very great, and if the I-function is placed in charge of determining ones most fertile time, errors are bound to be made.  Furthermore, it would be wasteful for the conscious effort to be spent on something that could be accomplished by an unconscious process.

            As exciting as it would be to have our sex lives controlled by an unseen force, that appears to not be the case.  Pheromones obviously exist in the world, and their presence is very obvious in a variety of animals and insects.  However, their existence/ potency in humans are yet to be determined.  Research is being done to find pheromone uses in our bodies, but for now everything is speculative.  If we turn out to use pheromones in our daily sex lives, it will lead to many questions about the strength of the I-function.  Perhaps natural selection is controlling our partner selection without us even knowing. 

[1] Pines, Maya. “Pheromones and Mammals.” Seeing, Hearing, and Smelling the World: A Report from the Howard Hughes Medical Institute. http://www.hhmi.org/senses/d230.html

[2] Ben-Ari, Elia T. “Pheromones: What’s in a Name?” Bio Science, Vol. 48, No. 7. (July 1998), pp 505-511

[3] Ibid.                                                                                                                    

[4] Ibid.

[5] Ibid.

[6] Ben-Ari, Elia T. “Pheromones: What’s in a Name?” Bio Science, Vol. 48, No. 7. (July 1998), pp 505-511

[7] Pines, Maya. “Pheromones and Mammals.” Seeing, Hearing, and Smelling the World: A Report from the Howard Hughes Medical Institute. http://www.hhmi.org/senses/d230.html

[8] Rantala, Markus. “Do Pheromones Reveal Male Immunocompetence?” Proceedings: Biological Sciences. Vol. 269, No. 1501. (Aug. 22, 2002). pp 1681-1685.

[9] [9] Ibid.

[10] Filsinger, Erik. “Odor Communication, Pheromones, Human Families.” Journal of Marriage and the Family. Vol. 47, No. 2. (May, 1985). pp 349-359