The great pheromone myth revisited (including biological factors in the development of sexuality)
Until recently, I thought that I could appropriately discourage attempts to semantically argue away the existence of human pheromones. These attempts were predicted in (Johnston 1998), and to discourage them I adopted the term “olfactory / pheromonal. ” I used this term more than 100 times in a detailed explanation of how pheromones elicit their effects on hormones, which is how pheromones affect human behavior (Kohl 2007).
Today I explored a series of internet links and found that (Fowler et al. 2003) appropriately also incorporated this term in their work: “The amygdala has been implicated in many reproductive-associated functions and behaviors, such as olfactory / pheromonal processing…” (p. 265) – my emphasis added. This passage continues and it incorporates a review of results that attest to the role of olfactory / pheromonal effects on learning and memory, copulatory acts, aggressive behavior, and the density of new cells in the amygdala, which are associated with plasma testosterone levels similar to those associated with mating.
The search that led me to (Fowler et al. 2003) followed after I read about the effects of pheromones on luteinizing hormone (LH) and neurogenesis in the brain (Lau et al. 2011). With their additional experiments, the review of results by (Fowler et al. 2003) indicates the physiological relevance of findings that, in male mammals, LH and testosterone play an important role in a male’s attractiveness to a female and his preference for a specific female’s odor. Pheromones drive this response. In addition to the effect of pheromones on testosterone and on male attractiveness, periods of reproduction have been correlated with high levels of testosterone and aggression and aggression increases a male’s reproductive success.
A commercial representation of these findings from 2003, is that pheromones associated with the testosterone levels of men affect women’s level of attraction and men’s sexual success. This substantiates my formulation of human pheromone-enhanced fragrance products for men.
The formulation is not driven by simplistic representations of cause and effect. It is supported by the fact that the secretion of testosterone, and its affects on the behavior of other mammal are driven by changes in LH, which are driven by changes in hypothalamic gonadotropin releasing hormone (GnRH) pulsatility. The mammalian pheromones. which Dr. Richard L. Doty tells us in his book do not exist, directly effect hypothalamic GnRH pulsatility. By denying their existence, Doty limits the further understanding of behavioral development associated with olfactory / pheromonal input, with GnRH, with LH, and with testosterone.
In contrast to his claims that mammalian pheromones, including human pheromones, do not exist, we have demonstrated an effect on hormonal conditioning of behavioral affects in a series of presentations that began with (Kelahan et al. 2007). The first of our presentations was at the 2007 annual meeting of the Association for Chemoreception Sciences (AChemS), and it predates Doty’s book publication.
I will attend the 2011 annual meeting of AChemS, and again present our results on human pheromones and their behavioral affects, which we have linked to their effect on LH in women. It is especially pertinent at this time to again address Dr. Doty’s semantic argument that mammalian pheromones do not exist, because there is overwhelming data that details their causal LH-driven affects on human behavior.
Clearly, our results must be viewed in the context of my commercial interests, which means they must also be independently replicated. It is also clear that our results must be viewed in the context of a mammalian model that accurately details across-species comparisons. These comparisons of an effect on hormones and an affect of human pheromones on behavior are consistent with the behavioral affects repeatedly and causally detailed in the existing literature.
This literature is also consistently ignored by researchers who report that there is no social model for the development of human sexual orientation (2011 citation pending). Arguably, one need look no further than the progression of articles that led Lau et al (2011) to find “…hippocampal neurogenesis in mice is due to the increase of the luteinizing hormone…” (p. 29). This effect of social odors on LH and on hippocampal neurogenesis is clearly associated with olfactory/pheromonal input. And, it “…is clear that sexual experience (or olfactory memory) also plays a role in mating and the olfactory / pheromone cues may be important for mating…” (p. 27)
Finally, my research, publications, and presentations, continue to address questions by others; “Why postulate that humans evolved only obligate olfactory/pheromonal preferences? Isn’t there likely to be useful information about mates that is better obtained through vision and touch than through smell? If so, selection would probably favor more reliable developmental patterns for visual and tactile preferences than classical conditioning to olfactory ones (Puts 2007).” (p. 783)
Answers: of course other sensory input from the social environment is important to the development of behavior. However, there is no evidence in any species that visual, tactile, or any other non-olfactory sensory input from the social environment, has the ability to classically condition the development of sex differences in hormone-dependent behavior. Researchers who continue to suggest that something other than olfactory / pheromonal input is directly responsible for the development of behaviors in other mammals, should suggest how this might occur, or minimally begin to challenge the findings that continue to show the mechanisms through which it occurs via olfactory/pheromonal input.
Fowler CD, Freeman ME, Wang Z (2003) Newly proliferated cells in the adult male amygdala are affected by gonadal steroid hormones. Journal of Neurobiology 57(3): 257-269.
Johnston RE (1998) Pheromones, the Vomeronasal System, and Communication: From Hormonal Responses to Individual Recognition. Annals of the New York Academy of Sciences 855(1): 333-348.
Kelahan LC, Hoffmann H, Kohl JV, Shea A (2007) Androstenol/androsterone may condition a human hormonal effect/behavioral affect. Association for Chemoreception Sciences 29th Annual Meeting,. Sarasota, Florida,.
Kohl JV (2007) The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences. In: Kauth MR, editor. Handbook of the Evolution of Human Sexuality. Binghamton: Haworth Press. pp. 313-369.
Lau BW-M, Yau S-Y, So K-F (2011) Reproduction: A New Venue for Studying Function of Adult Neurogenesis? Cell Transplantation 20: 21-35.
Puts D (2007) Arousing Imaginations. Evolutionary Psychology 5(4): 778-785