Epigenetics, science fiction, and scientific fact

In his book “Darwin’s Radio” (1999, Del Rey) and his sequel “Darwin’s Children” (2003, Del Rey), science fiction author and novelist Greg Bear successfully predicted that human endogenous retroviruses are involved in human speciation. His new subspecies of humans communicated with pheromones, as do other species from yeasts to non-human primates. This example of science fiction becoming fact contributes to a scientific understanding of epigenetics and human pheromones via a forward-thinking author’s grasp of molecular biology and his willingness to take the next logical step for his readers. Other fictional representations of human pheromones must also have some basis in fact; enough to be included on Wikipedia and other informative sources, if only to encourage forward-thinking by others. Indeed, in his November 2003 presentation before the American Philosophical Society, Greg Bear said: “What we [science fiction writers] write is far from authoritative, or final, but science fiction works best when it stimulates debate.” Moving forward as he spoke about epigenetic influences, he also said that chemical signals between organisms can change genetic expression. This allows the social environment to modify gene expression in individuals and in their offspring.

More than a decade has passed since Bear’s conceptualization of how pheromones might exert a powerful epigenetic influence on other species and on us. Those who are familiar with current works from molecular biology can now more fully recognize that Greg Bear was at least a decade ahead of his time. For example, see this article on human endogenous retroviruses and primate speciation. Also, my co-authors and I wrote about epigenetic influences and pheromones in 1996. The take home message that’s available through the integration of science fiction and scientific fact is that pheromones may be the most significant epigenetic influence of all. We are beginning to see this more clearly after our species sequenced the human genome and as we learn more about epigenetic facts predicted by Bear’s science fiction.

Molecular biology and social science theory

As I suspected might happen in the evolutionary psychology discussion group, a discussant incorporated molar level social science that I think skews the meaning and interpretation of what’s happening at the molecular level. The discussion about biological facts and social science theory leads nowhere when the facts change. For example, there are social scientists who are convinced that inbreeding is not detrimental to species survival. This means they need not examine further the data supporting reasons for the obvious and overwhelming genetic diversity among and across species.  No need to learn about human endogenous retroviruses and speciation if inbreeding is not detrimental.

Also, what I have consistently seen in my social science readings is a representation of dichotomous sexual differentiation, when what I support with molecular biology is that sexual differentiation occurs across life’s continuum. The molar level representation of “sperm competition” is so far afield of the molecular biology that discussion of differences will take decades.

In this regard, I’ve not seen any evolutionary psychology group-discussion about signals from the ovum that elicit chemotaxis; olfactory receptors in sperm; or the odor hedonics of bourgeonal. The integration of these topics from molecular biology suggests that sexual competition at the gamete level is not one-sided as is frequently represented and incorporated into social science theory. The lack of discussion of the enchanting female side of gamete competition makes me wonder how much longer it will be before someone writes a book on egg competition that catches the eye of the masses that might want to learn how to win the battle of the sexes with their eggs (or who might think they would be learning about how to win a food fight).

For an indication of how quickly molecular biology can make social science theory seem outdated and sometimes silly (at least to me) I’ve linked to two articles below that may be somewhat enlightening with regard to the molecular biology of gamete competition.

http://chemse.oxfordjournals.org/cgi/content/abstract/bjq030v1 Note: first example of a sex -specific phenotypic difference in olfactory sensitivity that favors males.

http://dx.doi.org/10.1007/s00359-010-0580-y Note: sperm chemotaxis controlled by olfactory receptors might be a general phenomenon in mammals

Is it what he or she sees in you, or is it your pheromones?

The expression of male secondary sexual characteristics is regulated by testosterone (T). Males with higher T levels are preferred by females in many species (Kohl, 2007). Roney, Simmons & Gray (in press) indicate that something other than facial cues of masculinity causes women to choose for visually perceived T-associated facial features. The female preference for higher T levels is a function of pheromones in other species.

Estradiol levels of females increase sensitivity and specificity for androgenic male pheromones, and predict preferences for T-associated androgenic male pheromones. This makes androgenic male pheromones, which are associated both with T production and with male secondary sexual characteristics, the most likely link between higher T levels and female preferences in all mammals. This link is supported by the fact that other female mammals do not seem to value visually perceived facial cues of high T. Simply put, other mammals don’t look for good-looking mates; they sniff out the one that smells best.

Indeed, several studies have consistently linked visually perceived physical characteristics to estradiol level-associated mate choice in women. At first glance, these studies suggest that the preference of women for higher T levels develops differently than it does in other female mammals. However, from a biological perspective, no mechanism has been described that allows for differences in the development of women’s preferences, when their development is compared to the pheromone-dependent development of other female mammals.

Snowdon et al.(in press) indicates that pheromones condition the sexual preferences of other primates. You can expect that the same is true for humans. Thus, Roney et al., seems to suggest that human pheromones condition the preferences of human females for T-associated physical features. These authors also show that visually perceived physical features may not be associated with subjective ratings of masculinity. Accordingly, if the right mixture of human pheromones is used, the man using the mixture may elicit preferential behavior from women who prefer men with higher T levels.

The unconscious affect of androgenic male pheromones on the preferences of women for increased T levels, seems to parallel the unconscious affect of estradiol-associated preferred waist-to-hip ratios in men, because this preference is demonstrated in congenitally blind men who have never seen a woman (Karramens et al., 2010).

The take home message for consumers who are interested in human pheromone-enhanced fragrance products is: Pheromones can make you smell like you look better! If you are interested in preferential treatment from others, please first consider the science of human pheromones that suggests how you can get it. Pheromones.com is dedicated to bringing you the latest science to support your wise purchase decision.

References

Kohl, J.V. (2007). The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences. Handbook of the Evolution of Human Sexuality. M.R. Kauth. Binghamton, Haworth Press: 313-369.

Karremans, J.C., et al. (2010). “Blind men prefer a low waist-to-hip ratio.” Evolution and Human Behavior 31(3): 182-186.

Roney, J.R., et al., (in press) Changes in estradiol predict within-women shifts in attraction to facial cues of men’s testosterone. Psychoneuroendocrinology (2010), doi:10.1016/j.psyneuen.2010.10.010

Snowdon, CT.et al. (In press). “Conditioned sexual arousal in a nonhuman primate.” Hormones and Behavior

Conditioned sexual arousal to odor

Here’s a link to an article abstract that indicates that pheromones condition sexual arousal to occur in the presence of other sensory input from the social environment (e.g., odors). However, because the sexual arousal is conditioned to occur, the researchers indicate that pheromones are not the cause of the arousal.

Conditioned sexual arousal in a non-human primate

Pheromones, by definition, effect hormones that affect behavior.  I don’t think most people would argue that pheromones are causing the arousal, because — in this case — the abstract mentions the hormone response. Obviously, some people are more reserved with their use of the term: pheromones. Clearly, it comes down to how you define the term pheromones, and what you expect to observe as a response.  But it should also become clear that some people do not want to extend the original definition of pheromones (as used for insects) to other species in cases where behavior is not quite so dependent on chemical signals from others.

Work by JVK with colleagues LCK and HH,  has shown that the mixture of chemicals in Scent of Eros increases flirtatious behavior and ratings of attraction when these chemicals are worn by a man who interacts with individual women during a 15-minute social construct. They didn’t check for any hormone response, but the mixture’s affect on hormone-associated behavior is probably the first real demonstration that human pheromones (i.e., as originally defined) exist, and also that the behavioral change in women is conditioned to occur in response to the chemicals we used. Once this conditioning has occurred, the pheromones are no longer required, although they can — in other species — elicit the conditioned response. The study linked above is the first demonstration of a conditioned response in another primate species.

Claims by others who may think they have discovered human pheromones, should include:

1. information about the mixture used (because pheromones are typically found in mixtures),

2. excuses for not using a study design that was typical of human social interaction, which is often brief.  (Reports that Athena pheromones are effective in 74% in 8 weeks do not indicate human pheromones are involved.)  See, for example:  Do perfume additives termed human pheromones warrant being termed pheromones?

3. excuses for using a supraphysiological amount of any chemical suspected of having a pheromonal effect on hormones or affect on behavior.  See for review: Human Pheromones: What’s Purported, What’s Supported.

Some researchers and marketers continue to hope consumers will gradually become better informed and make purchases, if any, based on science rather than on vague claims.

Scent of Eros pheromone-enhanced fragrance products

Created by James Vaughn Kohl, an internationally known clinical laboratory scientist and pheromone researcher, Scent of Eros products are the personification of his extensive research into how and why men and women react to human pheromones.

Scent of Eros for men and Scent of Eros for women are available from Luvessentials.com

• Scent of Eros (for Men) contains a pheromone mixture with a great musk fragrance in an easy to carry and ready-to-use roll-top bottle. The mixture increases flirtatious behavior in women and increases their self-reported level of attraction to the man wearing it

• Scent of Eros ( for Women) contains the copulin formula premixed with a light floral fragrance and ready to use in its easy to carry roll-top bottle. The copulin formula caused testosterone increases in men and also increased their ratings of photos and voices of women.

If you have any doubts about the effectiveness of these products, search the internet for  “James V. Kohl” or “Scent of Eros” and you will find a wealth of information explaining pheromones and how they can and do enhance desire.

To his credit, Kohl has received awards for his journal publications in neuroscience and in social science. He has published a book; a book chapter; and is the co-author of journal articles in:

“Journal of Psychology and Human Sexuality” (full text)

“Neuroendocrinology Letters” (full text)

and

“Hormones and Behavior” (abstract)

Unlike other researchers who have divested themselves from scientific pursuits and lost the respect of their peers, Kohl and his colleagues continue to present findings from their research during scientific conferences that include:

The Society for Neuroscience;

The Society for Behavioral Neuroendocrinology;

The Society for the Scientific Study of Sexuality;

The International Society for Human Ethology

Full disclosure of the formula, methods, and findings allow for replication of results and further the science of human pheromones.