The Great Pheromone Myth (opinion/review)
April 14, 2010 | jim
“If a man is offered a fact which goes against his instincts, he will scrutinize it closely, and unless the evidence is overwhelming, he will refuse to believe it. If, on the other hand, he is offered something which affords a reason for acting in accordance to his instincts, he will accept it even on the slightest evidence. The origin of myths is explained in this way.” Bertrand Russell (1872 – 1970)
The pheromone myth: Is a new concept needed?
In 1959, pheromones were originally defined as “…substances which are secreted to the outside by an individual and received by a second individual of the same species, in which they release a specific reaction, for example, a definite behavior or a developmental process.” Dr. Richard Doty misrepresents the original concept of pheromones when he indicates the concept infers “… that a plurality of mammalian behaviors and endocrine responses is uniquely determined in an invariant way by single or small sets of chemical stimuli….” (p. 3). Through his attempt to change the concept of mammalian pheromones, he also attempts to convince others that mammalian pheromones do not exist. Simply put, he builds a theoretical “straw man,” and then attacks it. In truth, it is inconceivable that any sensory stimulus from the social environment (e.g, an environment containing other members of the same species) determines anything about mammalian behavior in an invariant way.
The history of mammalian pheromones.
The definite behaviors and developmental processes in the definition of pheromones are released under the influence of luteinizing hormone (LH). James V. Kohl & Robert Francoeur (1995; 2002) conceptualized the link from mammalian pheromones to LH, and detailed the link from pheromones to LH, to other hormones, and to behavior. Both editions of their book “The Scent of Eros: Mysteries of Odor in Human Sexuality” offer an accurate conceptualization of mammalian pheromones, including human pheromones. The conceptualization is based on the original definition of pheromones and how they affect behavior. Their 2002 paperback adds an epilogue with additional citations to support the fact that “… many researchers recognize convincing evidence that pheromones do in fact alter levels of LH in other humans” (p. 277). Those researchers who do not recognize the importance of LH as a physiological link between pheromones and behavior, may not understand the physiology of mammalian reproduction or of mammalian sexual behavior.
It has now been nearly two decades since Kohl’s first presentation to a scientific forum. During this time Diamond, Binstock and Kohl (1996) linked pheromones both to the genetic and to the epigenetic mechanisms that are involved in the development of mammalian sexual behavior. Kohl et.al., (2001) detailed how human pheromones influence the development of heterosexual preferences. Using the same model, Kohl (2007) detailed the evolution of the mechanism that directly links pheromones to the development of typical and atypical sexual preferences across species, from yeasts to primates.
It is Kohl’s detailed concept of mammalian pheromones that Dr. Richard L. Doty avoids in “The Great Pheromone Myth”. He makes no reference to any of Kohl’s works, which include two award-winning journal publications and a book chapter in the “Handbook of the Evolution of Human Sexuality”. Given this notable absence of an evolutionary perspective, Dr. Doty shows that he lacks the tacit knowledge shared by others who are more familiar with this area of study, and who know what constitutes its subject matter. Minimally, they know where to look for information on the subject. For example, Kohl owns the internet domain pheromones.com and has maintained it as an information resource since its 1996 inception, while also promoting the science behind the development of pheromone-enhanced fragrance products.
It is not only other researchers who are familiar with the concept of mammalian pheromones. Indeed, most people know that mammals respond to the odors of their species. Internet access provides a wealth of information about mammalian pheromones. While some people might refer to scent, animal attraction, and chemistry when discussing olfactory cues, pheromones, and animal behavior, researchers like Kohl now equate the terms olfactory/pheromonal input and pheromones.
This consolidation of equivalent terms occurred because mammalian pheromones were repeatedly found to be volatile and processed by the main olfactory system (MOS). In the past they were thought to be non-volatile chemicals processed by an accessory olfactory system (AOS), which does not exist in some species, like humans. The MOS / AOS dichotomy, which was once exemplified through the use of terms like either odors or pheromones, gave way to use of the terms “olfactory (pheromonal)” and “olfactory/pheromonal.” “… probably evolved the capacity to cross correlate and match olfactory/pheromonal cues with visual (and other) cues…” “…it seems likely that olfactory (pheromonal cues) play some role in this process.” (p. 184). Here are two examples of how the newer and older terms have become interchangeable.
1. Olfactory/pheromonal cues guide a behavior in rabbit pups that allows them to locate their mother’s nipples. Olfactory bulb removal links the rabbit mammary pheromone (MP) to olfaction because it eliminates the stereotypical “nipple-search” behavior. The typical pup’s behavioral response occurs without prior exposure to its mother; rabbit pups that are delivered by caesarean section and immediately isolated from their mother exhibit normal nipple-search behavior. Obviously, the response is genetically predisposed to occur with the rabbit pup’s first postnatal exposure to maternal pheromones.
Dr. Doty argues that no one can be certain that the stereotypical response to the MP was not learned by the infant before birth. If the postnatal response is learned while exposed to chemicals in the uterine environment, he says that the nipple-search behavior is not due to a pheromone. Clearly, the mother’s natural odor (i.e., her pheromones) causes the response, but Dr. Doty tells us that a learned response to the mother’s natural odor means that no mammalian pheromones are involved.
2. According to Sachs (1997) with no prior sexual experience, some mature male rats exhibit penile erections when they are exposed to “…a volatile pheromone acting alone to evoke a sexual fixed-action pattern and, in that sense, acting as an airborne aphrodisiac” (p. 921).
Dr. Doty cites and quotes this work, but he says that no pheromones are involved because erections in this male mammal also can be elicited by the odors of some other animals. He argues that, technically, this means the erection is not a species-specific response to olfactory/pheromonal cues, and that means the response is not due to pheromones.
In the two examples above and in many others that are provided throughout his book, Dr. Doty finds either no evidence that a specific pheromone or pheromones cause “….a definite behavior…” (e.g., like nipple-search behavior) or he finds no evidence that pheromones cause “…a specific reaction…” (e.g., like the male rat’s penile erection). These examples indicate that Dr. Doty may not understand cause and effect.
The original definition of pheromones does not address whether nipple-search behavior is learned before birth, or whether learning before birth is even possible. It states that the reaction occurs due to “…a substance secreted to the outside by an individual and received by a second individual of the same species…” Obviously, the original definition of pheromones does not exclude a similar reaction that occurred due to the odors of other species. Unless the original definition of pheromones is discarded, I suspect that many people would agree that the rabbit pup’s nipple-search behavior and the rat’s erection are due to mammalian pheromones. Others, like Dr. Doty may need to be repeatedly reminded of the definition. ”Pheromones are defined as substances which are secreted to the outside by an individual and received by a second individual of the same species, in which they release a specific reaction, for example, a definite behavior, or a developmental process” (p. 55).
It is not inappropriate to add to a definition in attempts to clarify what a term means. Indeed, a wealth of new knowledge about mammalian pheromones has added to the original definition of pheromones, and these additions can be found in the recent literature on mammals. The original 1959 definition described insect pheromones, and it is often cited in review articles and books, as it is by Dr. Doty. Additions to the definition bring the term more current, as do recent research reports from molecular biology. Because there are few molecular biologists who understand the recently discovered physiological similarities among insect speces and humans, Dr. Doty takes advantage of a lack of consensus among today’s researchers about which additions to the definition are most helpful.
He pretends to take issue with the concept of mammalian pheromones in his preface by mentioning a few problems with the concept. “A third problem with this concept is that it assumes one or, at most, a few species-specific molecules of innate origin, largely impervious to learning and distinct from other types of chemical stimuli, are the motive influences.” (p. x). However, Dr. Doty does not provide any information on how he has conceptualized mammalian pheromones in accord with any currently used definition of pheromones. ” The Great Pheromone Myth” is actually a book about the definition of mammalian pheromones.
In 1996, it became more widely known that different species use unique blends of pheromones, which may include one or more of the same chemicals. Typically, it is a mixture of pheromones that causes a species-specific reaction. This cause and effect relationship goes relatively unmentioned by Dr. Doty, as he discusses the different classifications of mammalian pheromones. He virtually ignores the fact that pheromones are typically found in mixtures in his attempt to convince us that no specific individual mammalian pheromone exists.
Whether it is nipple-search behavior, erections associated with odor exposure, or any other response that seems to be driven by olfactory/pheromonal cues, Dr. Doty tells us there is no such thing as mammalian pheromones. At first, readers might think that he is merely playing the devil’s advocate (e,g., for the sake of argument). Most people know that male canines will “hump” a woman’s leg even though there are no species-specific pheromones involved in this behavior. Yet few, if any, people would argue that the dog’s response is not due to the scent of the woman because it is obvious that some dogs respond to women’s pheromones.
In contrast to Dr. Doty’s denial of common knowledge about mammalian pheromones, his redefinition of the term, and his conceptualization of how they must be “…at most, a few species-specific molecules of innate origin, largely impervious to learning and distinct from other types of chemical stimuli…” (p. x), Kohl has continued to focus on the original definition of pheromones and their effect on hormones, like LH, during the development of personal preferences associated with the visually perceived physical features of potential mates. In Kohl (2007) he writes: “As used here, mammalian pheromones, including putative human pheromones, are chemical signals from the social environment that elicit a measurable change in vertebrate levels of GnRH-directed LH in conspecifics.” This statement does not redefine or classify mammalian pheromones; it tells of their species-specific effect on hormones that affect behavior in other members of the species. In contrast to Dr. Doty new concept of mammalian pheromones, Kohl’s concept is consistent with their definition and it has not changed in more than 15 years.
In the mid 1990’s, Kohl began to look for research on the effect of mammalian pheromones on GnRH (gonadotropin releasing hormone), which is also called luteinizing hormone releasing hormone (LHRH). This hormone is unequivocally required for the release of a GnRH-directed luteinizing hormone (LH) response. He found that mammalian pheromones elicit an LH response, which is well known to occur in many different species. Furthermore, short-term exposure of males to females is linked — via this GnRH-directed LH response — to a testosterone (T) increase in men, as well as in rats, mice, rabbits, bulls, rams, and monkeys. The T increase in non-human mammals is believed to be due to the effect of pheromonal conditioning of an LH response that precedes the T increase (Graham & Desjardins, 1980).
It is the effect of mammalian pheromones on hormones like GnRH, LH, and T that links them to their affect on behavior. Kohl (2007) details the evolution of the neurophysiological mechanism and the pathways that are involved in the hormone responses of mammals to pheromones while using the original definition, which requires that they “…release a specific reaction, for example, a definite behavior, or a developmental process.” The specific reaction is a measurable LH response. This GnRH-directed LH response to pheromones is central to every ongoing process that is included during the development of mammalian behaviors, which include human behaviors. Nevertheless, throughout his book, Dr. Doty shows us how he can add to the definition of pheromones to technically make it seem that mammalian pheromones don’t exist. With exceptional skill, he injects terms and conditions that are designed to academically and intellectually make nothing out of something. For an uninformed readership he does this admirably, eloquently, and thoroughly. For those who already are convinced that mammalian pheromones don’t exist, Dr. Doty offers compelling, albeit inapplicable and confusing, evidence. This will not surprise those who are aware that Dr. Doty has no expertise on the topic of pheromones.
Why is there doubt?
Dr. Doty appears to be academically entrenched by his olfactory research on odors and his associated business interests in the development of smell tests. He argues from the book’s beginning, that the pheromone concept “…dichotomizes stimuli and complex behaviors into two classes—pheromonal and non-pheromonal—logically precluding the existence of multiple classes and continua.” (p. x). By definition, however, mammalian pheromones need only “…release a specific reaction, for example, a definite behavior, or a developmental process”. This does not preclude the existence of multiple classes of whatever affects a definite behavior or developmental process, and only death would preclude continua.
Different classes of pheromones influence behavior just as different classes of odors influence behavior throughout life. Food odors elicit ingestive behavior, but the odor of a rose does not cause us to eat the rose. Are food odors and the odors of flowers not merely different classes of odors? If so, a more appropriate dichotomy for the comparison of the effects of odors on hormones or the affect of pheromones on behavior would be alive or dead, since neither odors nor pheromones affect a dead mammal’s perception, behavior, or developmental processes. However, until death, the causes and effects of food odors, plant odors, or of social odors (i.e., pheromones) do not preclude the existence of multiple classes of everything to which we are exposed. Dr. Doty knows about odors but presents a false dichotomy when it comes to classes of mammalian pheromones.
Multiple classes of mammalian pheromones
It should surprise no one that multiple classes of mammalian pheromones have been defined by other researchers. “Primer pheromones typically affect endocrine or neuroendocrine responses such as the onset of puberty, estrus/menstrual cycle timing and onset and pregnancy disruption. Releaser pheromones typically elicit a behavioral response. Sexual attractants are the most common examples of releasers. Modulator pheromones have been, thus far, uniquely described for humans (2): These are chemosensory cues that modulate affect or context of other people. Signaler pheromones have been discussed as chemical signals that provide a variety of information to the smeller: sex of the sender, reproductive status, age and dominance status of the sender.” Dr. Doty seems to think these multiple classes (i.e., of mammalian pheromones) indicate that mammalian pheromones don’t exist. The researchers who have helped to classify them obviously think that mammalian pheromones do exist. Who’s thinking clearly?
It should be obvious that the effects of primers, releasers, modulators, and signalers are included in the original definition of pheromones that “…release a specific reaction, for example, a definite behavior, or a developmental process.” If this were not true, the different classes of pheromones would not be called pheromones, and Kohl et al., (1995; 1996; 2001; 2002; 2007) could never have accurately conceptualized them in the series of published works that Dr. Doty ignores.
No matter how they are classified, mammalian pheromones, by definition, meet the criteria to be specifically described as molecules of intrinsic origin. As they are in insects, they are essential for self / non-self recognition and recognition of potential mates in many, if not all, animal species. If a behavioral response to pheromones is correct, it will be rewarded. If not, either nothing significant happens, or there are consequences like injury or death to the individual organism — and possibly, even species extinction. The response, or lack of a response to mammalian pheromones, is a “survival of the species” concept that has been repeatedly detailed in examples of classical conditioning. which begins with molecular machineries that are common to insects and mammals.
How mammalian pheromones work
In more evolved species like mammals, classical conditioning of the response to olfactory/pheromonal input involves at least one other sensory stimulus from the social environment. In classical conditioning, one sensory stimulus is repeatedly paired with another sensory stimulus. This repeated pairing allows the second sensory stimulus to cause the same behavioral response that was initially caused by the first.
It may be important to emphasize that the second sensory stimulus can then cause the same behavioral response even in the absence of the first stimulus. The repeated pairing during classical conditioning tends to confuse some people about the relative significance of different sensory stimuli with regard to cause and effect. The significant stimulus is the initial sensory stimulus that causes the behavioral response. Only after conditioning can associated sensory stimuli gain significance.
Classical conditioning allows a relatively insignificant secondary sensory stimulus to affect behavior. In fact, the association of the secondary sensory stimulus with the first is the only way that the insignificant secondary sensory stimulus can become significant to the organism. Mammalian pheromones condition a hormone response that occurs with concurrent exposure to relatively insignificant sensory stimuli. Humans are the only mammals who can think that something other than mammalian pheromones might affect their behavior more than pheromones do, because other mammals can’t think. An accurate conceptualization of mammalian pheromones includes the fact that only humans can think about them. And most people know that all mammals respond to pheromones without thought, whether or not they think they do.
Comparing sensory input
Mammalian pheromones are sensory stimuli from the social environment. The social environment contains other member of the same species that produce pheromones, and respond to pheromones with changes in their behavior. Obviously, there are genetically predisposed behavioral responses to sensory input from the environment of mammals. Sunlight could help motivate cave-dwellers to explore what’s outside. But an environmental stimulus like sunlight is different than a sensory stimulus from the social environment. The social environment contains other members of the same species, and sensory stimuli from the social environment are rarely processed in the absence of other sensory stimuli from members of the same species.
Visual and/or auditory stimuli from other mammals are typically processed by sensory systems that allow for their association with the effects of olfactory/pheromonal stimuli on hormones and behavior. Thus, even though visual and/or auditory stimuli from other mammals has no direct effect on hormones, what mammals see and here can be indirectly linked to from visual and auditory stimuli to changes in hormones and behavior that are conditioned to occur by olfactory/pheromonal input.
Few people fully understand that visual and auditory stimuli from their social environment are insignificant sensory stimuli in the absence of the olfactory/pheromonal input, which is directly linked to changes in hormones and behavior. The concept is simple in mammals. If either visual or auditory stimuli from mammals directly caused changes in the hormones of other mammals, they could gain behavioral significance in the absence of olfactory/pheromonal input. Since they do not directly cause hormone changes, they cannot directly cause changes in mammalian behaviors, which are conditioned to occur with changes in their social environment.
It is here that Dr. Doty’s lack of tacit knowledge about mammalian pheromones; their effects on hormones, and the affects of hormones on behavior is most evident. If mammalian pheromones do not cause observed behavioral changes, which are invariably associated with hormonal changes, there is, simply put, no other sensory stimulus from the social environment of mammals that is capable of directly eliciting “ a specific reaction, for example, a definite behavior, or a developmental process.” This is not a matter of anyone’s concept; it is a biological fact. This biological fact is based on detailed and accepted levels of biological organization (e.g., a gene-cell-tissue-organ-organ system pathway, which is the only pathway that links sensory input from the social environment directly to behavior.)
Via this pathway it is their effect on the hormones GnRH, LH, testosterone, and other hormones that ensures mammalian pheromones can influence the concurrent maturation of the neuroendocrine system, the reproductive system, and the central nervous system. The concurrent maturation of these three systems is essential to the development of any reaction to any sensory stimulus from the social environment, which means it is essential to the development of definite behaviors like those that develop with exposure to pheromones that often occurs during concurrent exposure to other sensory input.
The ability of mammalian pheromones to condition hormone responses that are associated with the behavioral responses of an animal to other sensory input from its social environment is genetically predisposed and begins at birth. Dr. Doty tends to focus on the effects of mammalian pheromones in adults, without considering that he is looking at responses that have been conditioned to occur in the presence of other sensory input from the time the mammal was born. This brings us back to the maternal pheromones of the rabbit that elicit the nipple-search behavior.
Rabbits and humans are examples of mammalian evolutionary extremes, but the evolved neurophysiological mechanism (i.e., the hypothalamic GnRH pulse) that links pheromones to nipple-search and to other behaviors appears to be the same. Data from human neonates predicts that olfactory/pheromonal input is important to the development of human infants. However, the rabbit mammary pheromone (MP) has been isolated, while no human mammary pheromone has been isolated. The absence of proof that a human mammary pheromone exists is addressed in a recent article. Schaal et al., 2009 wrote that “…despite huge inter-specific variation in the structure and dynamics of the human female–neonate bond, the similarity of selective forces exerted on both partners [mother and child] in the dyad around birth may predict convergent solutions.” (p. 356). This means we can fully expect there to be a human mammary pheromone, whether or not it can be isolated. It also means that it is unlikely that anything besides human pheromones might be responsible for a human infant’s orientation to its mother’s nipple.
If Dr. Doty is correct in his claim that mammalian pheromones don’t exist, there would be no reason to attempt isolation of a pheromone from a rabbit or any other species of mammal. Yet research on mammalian pheromones specifically focuses on the isolation of human pheromones that influence the hormones and the behavior of other humans. For example, the successful demonstration by Graham and Desjardins (1980) that male rats can learn to secrete LH and T in anticipation of sexual activity is what led other researchers to look for, and find, similar effects in humans. “The Great Pheromone Myth” details the results of experiments on mammals that have repeatedly shown that mammals, including humans, produce and respond to the pheromones that Dr. Doty tells us, conceptually, don’t exist.
What’s missing from this picture?
Having found no evidence for mammalian pheromones in non-human animals, Dr. Doty turns to the topic of human pheromones and says that “… evidence for the existence of human pheromones is weak on empirical, conceptual, and methodological grounds.” (p. 125). Then, in his next sentence, but without citing a single piece of evidence, he tells us that “…odors and fragrances, like music and lighting, can alter mood states and physiological arousal….” Where’s his conceptualization of that? He seems to be saying that odors and fragrances can do what pheromones cannot.
If there is any evidence that the alterations in mood states and physiological arousal can be directly attributed either to a specific odor or to any specific fragrance, Dr. Doty should detail how a specific odor or fragrance alters mood states and physiological arousal. Are hormones involved? Do preferences for specific odors or fragrances develop throughout life, or are they simply manifest in reproductively mature organisms? These details are already available for discussions of olfactory/pheromonal input and pheromones; they alter mood and physiology by their effect on hormones throughout life.
The lack of evidence for direct effect of specific odors and fragrances on hormones and behavior in his book attests to the cognitive bias Dr. Doty appears to have developed during his years of research on odors and the human sense of smell. He seems to think that the effects of odors and fragrances on mood and physiology are exempt from any requirement to detail how these effects occur. But the overwhelming numbers of studies that detail precisely how mammalian pheromones influence hormones and behavior has not convinced him those mammalian pheromones exist.
This disparity in his thought processes might be expected from someone who has the tacit knowledge of cause and effect that has been acquired by those who are more familiar with the study of odors and fragrances than they are with the study of olfactory/pheromonal input and pheromones. Even if olfactory researchers like Dr. Doty don’t know what specific odors and fragrances elicit effects or how they elicit their effects, they know that somehow they do.
The disparity between what Dr. Doty accepts is true from his specialty, and what researchers who study mammalian pheromones accept is true begs the question of why someone who is familiar with unstated cause and effect in his area of study demands data that show a specific mammalian pheromone “uniquely” (p. 126) elicits a specific effect in a specific species? Why can’t the people who research mammalian pheromones be equally vague about olfactory/pheromonal cause and effect, even though this vagary is unnecessary? Can it not be simply said that olfactory/pheromonal input or pheromones, like music and lighting, alter mood states and physiological arousal? Dr. Doty appears to apply a different standard for making statements of fact based on mammalian pheromone research as compared to research on odors and fragrances. Why?
Whether the reaction is a definite behavior or a developmental process, genetically predisposed reactions to sensory input favor the organisms’ survival (Panksepp et al., 2002). For example, a hormone response to olfactory/pheromonal input that is paired with visual input favors the organism’s survival if it allows for proper food choice. Thus, Doty is correct when he writes that influences from multiple chemicals “… depend as much on the receiver as the sender, commonly being influenced by the receiver’s prior experience and motivational state.” Obviously, the receiver’s prior experience with multiple sources of sensory input influence motivational state. This makes it difficult to predict the response of any organism to any source of sensory input, unless we know how that organism has been conditioned by to respond during a lifetime of experiences.
For example, food that elicits salivation is presented each time a bell is rung, and this results in the bell eliciting salivation even in the absence of food. If a dog is never subjected to the food-bell pairing, the bell will not elicit any conditioned response. In precisely the same manner, if any mammal’s response to visual input has not been conditioned by olfactory/pheromonal input, which is associated with the visual input, it cannot exhibit the correct behavioral response to the visual input. Similarly, if you showed a dog a picture of the food, the dog could not appropriately respond in the absence of food odor. The human response to erotic imagery or to someone whose pheromones cannot be detected due to the distance between them, is another example. The response has been conditioned to occur across a lifetime of exposure to the social odors from other people. It doesn’t simply happen, as many social scientists would have you believe. And if the response is not due to culture in the dog, the social scientists should quit saying that the response is due to culture in humans.
After all is said, and he is done telling us there are no mammalian pheromones, Dr. Doty, like many social scientists, is left to detail how humans and other mammals respond to visual, auditory, or other sensory input from the social environment, if the response is not conditioned to occur in the presence of olfactory/pheromonal cues. For comparison, since he is an olfactory researcher, he could start by explaining how food acquires its significance in the absence of its chemical appeal.
Food choice and mate choice are both functions of “chemistry” in all species—even those with no eyes, as is generally known. Arguably, this is so well known, that it is responsible for men and women acknowledging the role of “chemistry” in their attraction to each other. Using whatever model Dr. Doty determines is applicable to food choice, he could then attempt to explain how any mammal becomes interested in the visually perceived physical characteristics of another member of their species if that interest is not directly dependent on olfactory/pheromonal conditioning of hormones and behavior.
Dr. Doty’s admits early on that “Some critics will view my argument as simply one of semantics.” (p. 3). I agree, and think that most people will find it odd that he uses semantics in his effort to tell others there’s no such thing as mammalian pheromones. No other established researcher has “…inferred that a plurality of mammalian behaviors and endocrine responses is uniquely determined in an invariant way by single or small sets of chemical stimuli….” (p. 3). So how could Dr. Doty’s argument that mammalian pheromones don’t exist be anything other than a argument about the terms that should be used? He’s not truly arguing against the concept of mammalian pheromones, and he’s not attempting to present a new concept. He’s simply playing word games.
As Dr. Doty indicates, claims of invariant behavioral responses to human pheromones come from the marketers of products who prey upon insecure humans who think there is something like a love potion that will get them more sex. That’s the myth, a story told that has no basis in fact. But, so far as mammalian pheromones are concerned, there’s no great pheromone myth. They have repeatedly been shown to cause changes in the hormones and behavior of other members of their species, and also to cause some cross-species reactions. They’re real! Mammalian pheromones, including human pheromones, cause changes in hormones and behavior, although marketer’s reports of the dramatic effects of unidentified human pheromones on human sexual interest and behavior may be somewhat mythical.
What human pheromones do
This does not mean that human pheromones have no effect on others. It simply means that the effects are more subtle and less predictable than some product marketers would have you believe. Human pheromones might best be compared to other cosmetic products, like make-up, that supposedly makes people more visually appealing.
In truth, human pheromones could be compared to anything that makes another person more attractive, because attraction is conditioned by olfactory/pheromonal input. This is why human pheromones can be expected to make someone appear to be more visually appealing. Since visual appeal is a function of chemical appeal, adding the right chemicals to one’s scent signature can positively influence their overall appeal, as has been shown by one research group whose work has not yet been published. It was presented at a 2009 conference that was attended by Dr. Doty, who must have missed it the year before, also.
Other ways to improve chemical and visual appeal
The concept of human pheromone use for increased visual appeal is one that most people are familiar with, but few people recognize. Simply put, anything that anyone does to appear more reproductively “fit” also positively effects the hormones that determine their pheromone signature.
Men who exercise to build muscle mass are increasing their testosterone level. Their conversion of testosterone results in a more masculine pheromone signature. Ovulatory phase women display more proceptive behaviors when their levels of estrogen-associated pheromones most effectively may influence men’s behavior. Women who use make-up to signal the red color associated with fertility also may be attempting to get men to notice their pheromone signature, which varies with fertility. Men and women who maintain proper height to weight ratios, avoid fat tissue that may be unappealing to see, but that also converts hormones to pheromones associated with aversion.
This multisensory concept of olfactory-visual integration should not be a difficult concept to master. We need only realize that other animals do not lift weights or use make-up to enhance their reproductive fitness-related appeal. Their pheromone signature either changes at the time most opportune for reproductive sexual behavior, or they are left without a mate.
Obviously, there’s more to it than that for men and women. But what makes the most difference of all is still our pheromones, just as it is for every other species of mammal on the planet. If you want to learn more, you can find information about human pheromones at many scientifically based internet domains. But, unlike Dr. Doty, who appears never to have looked at pheromones.com, you might do well to start looking at the most logical scientific source for information.