Human Pheromones

Human Pheromones

Scent of Eros products unsolicited 5-minute video testimony and twin test

Scent of Eros products contain human pheromones. Like other products that may or may not contain human pheromones, they are not aphrodisiacs — despite their very positive representation in this promotional video, which was produced without my knowledge.

Scent of Eros products have a very positive influence on other people, which is a great thing to promote.  It’s just best not to get too carried away by claims of magical effects. My focus has always been on accurate representations of scientific information about human pheromones, and my focus has not changed since I acquired this domain in 1996. You’ve probably already seen the misrepresentations, so I hope you will take a brief look at the information on this site. The complexity of the concept is more than what most people will grasp — unless they are specialists. However, you need not grasp the complexity to have fun using products that contain human pheromones, like those marketed here.

Human Pheromones: 2010 Powerpoint slides and 2011 poster presentation

Here are the slides with text from a 20 minute-long presentation: Human pheromones: linking neuroendocrinology and ethology (revisited)

20th Biennial Congress of the International Society for Human Ethology 2010, 1 – 5 Aug 2010, Parallel Session A

Background / Purpose: Their conversion from chemical signals to the mammalian brain’s common language of electrical signals allows food odors and pheromones to activate genes. In this mammalian model, electrostatic gene activation by pheromones links them to a marker of neuronal activity, gene expression, and changes in hypothalamic gonadotropin releasing hormone (GnRH) secretion.

Main conclusion: Changes in GnRH secretion are evidenced in downstream effects on other hormone secretion throughout the hypothalamic-pituitary-gonadal (HPG) axis and hypothalamic-pituitary-adrenal (HPA) axis. Food odors and pheromones activate the prenatal organization of the HPG and HPA axes and postnatally “calibrate” the genetically predisposed survival potential of individuals and species. Calibration of odor preferences occurs via effects on synaptogenesis, synaptolysis, and apoptosis throughout life. In mammals, these effects of odors are routinely associated with neurotransmission, hippocampal neurogenesis, learning, and memory during classically conditioned hormone-driven changes in behavior. In people, these neurophysiological effects of calibration by odors are typically consciously associated only with input from spectral senses (e.g., vision and hearing), or tactile sensations.

Next steps: Extension of this mammalian model to people explains how cerebral activation of hormone-secreting neurons and processes commonly attributed to individual components of the model, like genes or hormones, result in genetically predisposed phenotypic expression, which may or may not be physically or behaviorally manifested during development. The explanation includes (1) a cognitive component associated with the identification and categorization of some odors; (2) an emotional component associated with odors and increased or decreased arousal, appetite, and satiation; (3) a motivational component linked to processes that direct behavior toward or away from food odors and pheromones; and (4) a neurophysiological component, directly linked from odors to gene activation in hormone-secreting nerve cells of brain tissue; to HPG / HPA axis variability, and to behavior.

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An updated poster presentation of the one presented in 2010 is also available: Human pheromones, epigenetics, physiology, and the development of animal behavior.

Association for Chemoreception Sciences Annual Meeting 2011, 13 – 17 Apr 2011, 301

Background/Purpose: We evaluated individual video-taped fifteen-minute interactions of fourteen women with fertile phase levels of Luteinizing Hormone (LH) during a cooperative task. During the task, our male accomplice wore either a standardized androstenol / androsterone mixture diluted in propylene glycol, or just the diluents; with sandalwood odor added to keep him blind to his condition.

Main conclusion: When he was wearing the mixture compared to when he wore the diluent, women were more likely to make eye contact (t (12) = 3.43, p = 0.01; IRR: r = 0.964, p = 0.01). They also laughed more (t (12) = 5.20, p < 0.01; IRR: r = 0.810, p = 0.01), and they subsequently rated themselves as being more attracted to him (t (12) = 2.786, p = 0.016).

Our results combine the known effects of androstenol on LH and on mood with a likely behavioral affect of androsterone.

Nutrient-dependent / Pheromone-controlled Adaptive Evolution: A Model” (accepted 5/13/13)

Coming of age in the evolutionary behavioral sciences: A review of Nicholas B. Davies, John R. Krebs, and Stuart A. West, An Introduction to Behavioural Ecology, 4th Edition

Evolutionary Psychology 11(2): 347-349 H. Clark Barrett Download PDF (free)

Excerpt: “Who would have thought, just a few years ago, that we would be able to study sexual conflict at the molecular level… or that microbes would become wonderful experimental models for studying the evolution of social behaviour…”

My comment: We incorporated the study of sexual conflict at the molecular level when we began to detail a model for the adaptive evolution of sexual behavior  in our 1996 review article: From Fertilization to Adult Sexual Behavior. We wrote: “…if specific genes or genomic regions are found to be primary determinants of sexual orientations, upstream and downstream genes are likely also to play crucial roles. And these multigene interrelationships will have profound impact upon phenotypes and judgments derived therefrom.” (We included a section on molecular epigenetics and elaborated on this fact: “Yet another kind of epigenetic imprinting occurs in species as diverse as yeast, Drosophila, mice, and humans.”)

The next sentence from the same paragraph quoted above addresses the fact that microbes are “wonderful experimental models for studying the evolution of social behaviour…” We wrote “Parenthetically it is interesting to note even the yeast Saccharomyces cerevisiae has a gene-based equivalent of sexual orientation (i.e., a-factor and alpha-factor physiologies). These differences arise from different epigenetic modifications of an otherwise identical MAT locus (Runge and Zakian, 1996; Wu and Haber, 1995).”

The development of this model incorporated what is neuroscientifically known and resulted in 2012 publication of  Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. The concluding sentence is: “Olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans.”

The answer to the questions about who would have thought about sexual conflict at the molecular level, or that microbes could be used to model social behavior is clear. My coauthors and me in 1996,  and in 2001. It was me again in a 2007 book chapter, and in a 2012 review will soon be me again in “Nutrient–dependent / Pheromone–controlled Adaptive Evolution: A Model” (submitted 3 Feb 2013 accepted 13 May 2013).

Now, the questions are: 1) Who thinks that evolutionary theory did not long ago move from story-tellling to accurate representations of established facts?  2) How much longer will it be until evolutionary theorists grasp the fact that adaptive evolution is nutrient-dependent and pheromone-controlled in species from microbes to man?

At least a decade ago, it should have been clear that “Behavioural ecology” incorporates what I began to detail about ecological, social, neurogenic, and socio-cognitive niche construction in my first presentation to a scientific forum in 1992, and then with co-author Robert Francoeur  in a 1995 book (paperback 2002) before publishing in the research journals. Who can we thank for muddying up that clarity with their ridiculous opinions and commentaries? Who still knows nothing about the basic principles of biology and levels of biological organization required to link sensory input to behavior in species from microbes to man? When will everyone understand the importance of Behavioural Ecology?

Nutrient dependent epialleles vs mutations

Excerpt: Epialleles are heritable, nongenetic (epigenetic) differences in DNA methylation…. Regions in the genome may undergo spontaneous changes in their epigenetic status, and these differences may be one evolutionary mechanism affecting the evolution of new genes. PLoS Genet. 9, e1003437 (2013).

My comment: Does the concept of epialleles in plants extends to animals via the epigenetic effects of plant nutrients (e.g., starch) on the thermodynamically controlled microRNA/messenger RNA balance and organism-level thermoregulation? If so, it might clarify how the molecular mechanisms for de novo gene expression have been conserved across plant and animal species. For example, microRNAs from plants may have facilitated the nutrient-dependent adaptive evolution of species from microbes to man via ecological, social, neurogenic and socio-cognitive niche construction. Indeed, the ecological niche construction of the first animals may have required different plants as sources of various nutrients that led to epigenetically-effected social niche construction and species diversity in animals.

Obviously, the diversity begins in microbes but we’re now beginning to see how important starch metabolism can be to differences in the adult behavior of wolves and dogs. At the same time, we see that starch production in plants and starch metabolism may have contributed to adaptive evolution in a human population. This appears to link the starch diet of humans to dog-human co-evolution in the context of the origins of agriculture. Once again, however, this evidence of nutrient-dependent changes suggests that mutations theory is somewhat ridiculous compared to a model of nutrient-dependent pheromone-controlled adaptive evolution. And here we have an article that compares mutations theory in the context of epialleles and suggests that epialleles have greater explanatory power (see below).

Article excerpt (full text is free) “…given that epigenetic variation enables genes to adjust their expression in a heritable manner much more rapidly than through mutation while preserving the possibility for rapid reversion, it could prove particularly beneficial in the case of genes that are created from scratch. Once the most adaptive expression state is reached, it could then become irreversibly stabilized (i.e. genetically assimilated) through DNA sequence changes.”

My comment: In animals,  nutrient-dependent pheromone-controlled epigenetic “switching” enables adaptations to changing environments during development (e.g., exemplified in the honeybee model organism). For contrast, mutations may permanently perturb intracellular signaling and internuclear interactions to result in their typically detrimental effects. Mutations are less likely to be beneficial because epistasis cannot be achieved without their control. Mutations don’t control mutations. Therefore, I think it falls on the theorists and philosophers to explain mutations theory in the context of what is currently known about biological facts that include the concept of nutrient-dependent pheromone-controlled adaptive evolution.

Pheromones and exploration forge differences in twins and species

Exploration forges differences in identical twins
By Puneet Kollipara Web edition: May 9, 2013

Excerpt: “Scientists have recognized that having distinct experiences within the same environment 
might boost such personality differences, but that’s difficult to test in humans.”

My comment: How can the difference that is clearly  forged by exploration in identical twins not be due to the same molecular mechanisms that explain the differences forged by exploration in wolves and dogs or other mammals? The differences are due to experience with food odors and pheromones See: 5-10,000 years of nutrient dependent pheromone controlled adaptive evolution.

5-10,000 years of nutrient dependent pheromone controlled adaptive evolution

New discovery of ancient diet shatters conventional ideas of how agriculture emerged (reported 5/17/13)

News article excerpt: “We have used a relatively new method known as ancient starch analysis to analyse ancient human diet. This technique can tell us things about human diet in the past that no other method can.

Article excerpt:The initial cultural migration from southern China is thought to have occurred sometime around or prior to 5,000 years ago. The dominant starches… suggest that the sago palms were an important plant food prior to the rice in south subtropical China. This… provides the first evidence for the exploitation of resources in a coastal village community in southern subtropical China around 5,000 years ago, and may represent a common strategy that prevailed in Southeast Asia before rice farming was practised widely (Yang et al., 2013).

See also: Analysis of 6,515 exomes reveals the recent origin of most human protein-coding variants (e.g, during the past 5-10,000 years of nutrient-dependent pheromone-controlled adaptive evolution).

My comment: Ancient starch analysis is a technique that tells us it is time to replace misrepresentations about the role of mutations in adaptive evolution with biological facts, which are exemplified in model organisms from microbes to man. The technique challenges the misrepresentations of adaptive evolution commonly accepted by evolutionary theorists and incorporated into their “Just-So” stories. Thus, it may be important to put the latest information on what might at first appear to be cultural evolution (e.g., as in agriculture) into its proper perspective of nutrient-dependent pheromone-controlled adaptive evolution. Fortunately, there is a model for that. The mammalian model can be used to specifically address the influence of starch in the diet and its metabolism to pheromones that control social behavior and reproduction.

Differences in their diet and in their metabolism of starch (Axelsson et al., 2013) contribute to differences in the socialization dogs and wolves. The differences in socialization of these subspecies can be attributed to explorations involving only olfactory/pheromonal input in 2 week-old wolf pups. For comparison, by the time dog exploration begins approximately 2 weeks later,  visual and tactile input have added details of the sensory environment. A dog’s perspective develops  in the context of  multisensory input (Lord, 2013). A developmental delay of approximately 2 weeks allows multisensory input and additional details in dogs to complement what is learned by wolves from only olfactory/pheromonal input.

The developmental differences exemplify the epigenetic effects of olfactory/pheromonal input on nutrient-dependent pheromone-controlled brain development and socialization during a critical period of interaction with the environment. The differences in behavior extend across a life-time of more aggressive behavior in wolves. It seems likely that wolves have not been domesticated because the impact of their diet (i.e., less digested starch) genetically predisposes wolf pups to begin exploration of their postnatal environment using only their sense of smell. The wolf pups are then somewhat ‘shocked’ when associations with other sensory input begin to alter their behavior. They may be less trusting of other large mammals that also smell like a nutrient source. The handling by humans of cute little puppy-dogs that occurs in the context of multisensory input might make a huge difference in their adult behavior and their trust and ‘love’ of some people, but not all people. Learned behaviors are genetically predisposed and experience-dependent. Some dogs may not be as trusting as others, and the experience of some dogs with some people may make a dog’s behavior more wolf-like.

If only the species-specific differences in the development of behavior between wolves and dogs were considered, it would be clear that there are differences in the nutrient-dependent production of species-specific mammalian pheromones, and that these differences are important to the development of behavior in sub-species. Does that fact help to explain the importance of discussing nutrient-dependent pheromone-controlled adaptive evolution in the context of olfactory/pheromonal control of adaptively evolved hormone-organized and hormone-activated socioaffective neuroscience and psychology (Kohl, 2012)?

Indeed, mammalian pheromones are included in discussions that are essential to understanding the role of molecular epigenetics and the ecological epigenetics of nutrient-dependent pheromone-controlled reproduction in species from microbes to man. Furthermore, the concept of nutrient–dependent pheromone–controlled reproduction is important to neuroscientific progress. For example, it is essential to better understanding of evolutionary endocrinology (Zafon, 2012) and its role in evolutionary medicine (Stearns, 2012).

The opportunity has again arisen to discuss mutations theory in the context of cultural evolution, agriculture, and nutrient-dependent adaptive evolution in a population in China. Everyone is welcome to start the discussion of how mutations led to agriculture, culture, or anything else involved in the adaptive evolution of the human brain and behavior, which is obviously nutrient-dependent and pheromone-controlled.

Who will now begin to tell us how mutations are involved and how their effects on adaptive evolution are controlled?  

Bibliography

Axelsson, E., Ratnakumar, A., Arendt, M.-L., Maqbool, K., Webster, M. T., Perloski, M., et al. (2013). The genomic signature of dog domestication reveals adaptation to a starch-rich diet. Nature, 495, 360–364.

Kohl, J. V. (2012). Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2(17338).

Lord, K. (2013). A Comparison of the Sensory Development of Wolves (Canis lupus lupus) and Dogs (Canis lupus familiaris). Ethology, 119(2), 110-120.

Stearns, S. C. (2012). Evolutionary medicine: its scope, interest and potential. Proc Biol Sci 279(1746), 4305-4321.

Yang, X., Barton, H. J., Wan, Z., Li, Q., Ma, Z., Li, M., et al. (2013). Sago-Type Palms Were an Important Plant Food Prior to Rice in Southern Subtropical China. PLoS ONE, 8(5), e63148.

Zafon, C. (2012). Evolutionary endocrinology: A pending matter. Endocrinologia y Nutricion (English Edition), 59(1), 62-68.

Nutrient dependent pheromone controlled bacterial methylomes

Nutrient dependent pheromone controlled adaptive evolution of teeth

Excerpt: “The teeth begin growing before birth…

If early weaning was typical of Neandertals, Humphrey says, it would be consistent with other evidence for a “faster pace of development” and raise the possibility that Neandertal mothers had shorter intervals between births and thus more kids on their hands at any given time.”

My comment:

Nutrient-dependent pheromone-controlled adaptive evolution of teeth and nutrient-dependent pheromone-controlled neurogenic niche construction are exemplified in nematodes.

In my model of adaptive evolution, change in a single base pair results in an amino acid substitution manifested in increased apocrine glands (e.g., in mammary tissue), increased eccrine glands (e.g., important for thermoregulation), thinker hair (e.g., a likely trait for sexual selection), and changes in teeth in a human population that arose in central China during the past ~30,000 years. Because the molecular mechanisms of adaptive evolution are the same across species, change in a single base pair could result in differences in Neandertal / modern human weaning associated with the mother-infant bond and nutrient-dependent pheromone-controlled adaptive evolution of the mammalian brain and behavior. Ultimately, change in a single base pair could result in enhanced neurogenic niche construction and socio-cognitive niche construction.

Presumably, this result would exemplify less stressful nutrient-dependent ecological niche construction and less stressful pheromone-controlled social niche construction. If so, my model, which is exemplified in the honeybee model organism of socio-cognitive niche construction and embodied cognition, links the epigenetic effects of nutrients and their metabolism to species-specific pheromones to the adaptive evolution of species from microbes to man.

If not, “…it should be mentioned that another possibility is that of mutation accumulation in the strains [of nematodes] used in the different studies.” (p. 168). However, it should also be mentioned that the molecular mechanisms of adaptive evolution are unlikely to vary across species, which means adaptive evolution is probably nutrient-dependent and pheromone-controlled in all species. If mutations are involved in adaptive evolution there may be a model organism other than those that are known to exemplify how mutation accumulation enables selection and epistasis.

Nutrient dependent pheromone controlled morphogenesis (revisited)

The developmental genetics of space and time: Developmental genes often take inputs from two independent sources

May 15th, 2013 in Biology / Cell & Microbiology

Excerpt: “Understanding the concept of morphogen gradients—the mechanism by which a signal from one part of a developing embryo can influence the location and other variables of surrounding cells—is important to developmental biology, gene regulation, evolution, and human health.”

My comment: I am reminded by the content of this articlethat I have not yet published a preprint about nutrient-dependent pheromone-controlled morphogenesis in species from microbes to man. As most of you know, however, nutrient-dependent pheromone-controlled morphogenesis is included in my model of nutrient-dependent pheromone-controlled adaptive evolution.

Although I find no fault with the portrayal of morphogenesis in the fruit fly model, I will note that nutrient-dependent pheromone-controlled morphogenesis is probably best exemplified at the advent of sexual reproduction in yeast. See: Pheromone-Induced Morphogenesis Improves Osmoadaptation Capacity by Activating the HOG MAPK Pathway and see also: Feedback between Population and Evolutionary Dynamics Determines the Fate of Social Microbial Populations. An alternative invertebrate representation can be found in Ecological selection as the cause and sexual differentiation as the consequence of species divergence?

Taken together it has become perfectly clear that natural selection and nutrient-dependent ecological divergence precedes sexual divergence and pheromone-dependent sexual selection in the only model of adaptive evolution that incorporates what is currently known about the conserved molecular mechanisms of epigenetic cause and effect (e.g., among microbes; among populations of flightless crickets confined to the Virgin Islands; and in a human population that arose during ~30,000 years in central China).

Pheromones and the adaptive evolution of lying

Nutrient-dependent pheromone-controlled adaptive evolution of lying.

Excerpt: “Cooperation makes it possible for some individuals to cheat, prospering off the cooperative efforts of others. Cooperate too readily and you might get taken for a ride. Cooperate only grudgingly and you don’t reap the benefits of working together.”

My comment: Their theoretical model appears to have its factual/ biological basis in eco-evolutionary trajectories at the unicellular level of molecular mechanisms for survival of the species. See for example: Feedback between Population and Evolutionary Dynamics Determines the Fate of Social Microbial Populations.

Abstract except: “We directly visualize eco-evolutionary trajectories of hundreds of populations over 50–100 generations, allowing us to characterize the phase space describing the interplay of evolution and ecology in this system. Small populations collapse despite continual evolution towards increased cooperative allele frequencies; large populations with a sufficient number of cooperators “spiral” to a stable state of coexistence between cooperator and cheater strategies.”

Our existence may be equally dependent on liars and cheating, as indicated. However, this may make it no easier to tolerate the lies of your boss, co-workers, family or friends. Ultimately, co-operation with liars ends, although for most people it does not end soon enough. In part, that explains why everything ends badly. If it didn’t end badly, it wouldn’t end.