The Secret Power of Pheromones
Cosmetics that guarantee (according to manufacturers) success with the opposite sex can be bought not only in specialized stores for adults, but also in any pharmacy or perfume store. But how much can you trust the promises on the labels of "Casanova perfume"?
The influence of pheromones on human sexual behavior has been studied quite recently. The information that reaches the mass reader is often based on speculation, guesswork and the results of research conducted with the money of companies producing new-fangled love elixirs. The pheromones of insects and some mammals are much better studied – let's start, as it should be, with butterflies.
From the life of insects
The fact that it is by the smell of male butterflies that they determine where the female is, even in the XIX century, the French entomologist Jean-Henri Fabre suggested. This was confirmed only in the late 1950s by a group of German scientists led by Adolf Butenandt. In the name of science, they have exhausted half a million female silkworms to isolate all volatile substances from their sex glands, separate them on a chromatograph and show that only one of them makes male silkworms flutter their wings. This substance was called bombycol, in honor of the genus Bombyx, which includes silkworms.
Butterflies before the discovery of pheromones were suspected of telepathy: some of them flock to the female from a distance of several kilometers! Male silkworms are able to smell bombycol – trans-cis-hexadecadiene-10,12-ol-1 – at a concentration of approximately 250 molecules per cubic centimeter of air (10-19 g/ml). The next most attractive isomer of the same substance acts a billion times worse on silkworms. For comparison, the most odorous substance for humans – wine lactone – we feel at a concentration hundreds of times greater – 10-17 g (45,000 molecules) per milliliter.
Soon, similar substances were found in many species of insects, as well as in amphibians, reptiles, fish and mammals (they have not yet been found in birds). The term "pheromones" is formed from the Greek φέρω – "to carry" and ορμόνη – "to set in motion, to induce" (the well-known word "hormone" comes from the same root).
Pheromones belong to dozens of classes of chemical compounds. What unites them is that animals release these substances into the environment, and in individuals of the same species they cause certain instinctive behavioral or neuroendocrine reactions. Pheromones can not only attract, but also cause fear or aggression (or vice versa – the desire to regurgitate a drop of food to a neighbor on an anthill). If an ant finds prey, it will run along the path marked with the smell "home – there", leaving another signal on it: "food is there". (One milligram of methyl ether of 4-methylpyrrol-2-carboxylic acid would be enough for Atta texana ants to mark a path three times longer than the earth's equator.) Many pheromones act not on behavior, but on the biochemical and physiological processes of neighbors – for example, they induce puberty or sex change (any aquarist can see how they do it female swordsmen in the absence of males). Mammals often use odors to mark territories and as business cards with detailed information about themselves (ask dog owners for details).
The fragrance of a woman
The role of pheromones in mammalian life has been most fully studied in the field of sexual behavior and reproduction. For example, in experiments on mice, it was found that females prefer the smell of dominant males, which at the same time suppresses puberty and the activity of other males, reducing their chances of reproduction. Moreover, the smell of the dominant male causes termination of pregnancy in the early stages, which allows the female to re-conceive potentially more viable offspring.
As a result of many experiments on laboratory mice and rats, scientists have come to the conclusion that animals relying mainly on their nose in intimate affairs choose individuals from all available partners with a set of histocompatibility genes that differ as much as possible from their own. The complex of proteins encoded in them not only causes tissue rejection during transplantation, but also largely ensures the effectiveness of the immune system. The more diverse these genes are, the greater the spectrum of antibodies designed to fight various infectious agents, the immune system can produce, which ultimately determines the survival of the organism and its ability to adapt to changing environmental conditions.
Naturally, experts have suggested the possibility of the existence of a similar relationship in humans. One of the approaches used to test this hypothesis is the so-called "sweaty T-shirts" method, when women are given to smell the worn T-shirts of different men and are offered to choose the most pleasant smell for them. In such experiments, women overwhelmingly prefer men who differ from them as much as possible in histocompatibility genes – provided that they belong to the same race. The latter can be explained by the fact that too large differences in genotypes can deprive a couple of viable offspring altogether. Perhaps it is for this reason that many people with white skin find the smell of blacks extremely repulsive, and Asians often do not tolerate the smell of Caucasians, finding it unpleasantly sharp and sour.
Are all men pigs?
The study of large representatives of the animal world brought more "delicious" fruits. So, it turned out that the smell of androstenone contained in the urine and saliva of wild boars – a metabolite of the male sex hormone testosterone – paralyzes female pigs in the position most convenient for copulation, even if there is no wild boar nearby. Androstenone was also found in the saliva and sweat of human males.
Male sex hormones (androgens, from Greek. andros – male) belong to the group of C19-steroids. The precursor of androgens is cholesterol (attention vegetarians: vegetable fats do not contain cholesterol!), which in several stages turns into the most famous male hormone – testosterone (Latin testis – testicle). In fact, testosterone is a semi–finished product - a prohormone. In target organ cells, the enzyme 5α-reductase cleaves an oxygen atom from a skeleton of 19 carbon atoms, converting testosterone into a biologically active form – dihydrotestosterone. Androgens regulate many processes – both metabolic and mental, but for the topic of this article, such a small but curious detail is of the greatest interest: the composition of sweat in both sexes contains the main candidates for the role of male pheromones, C19-the steroids androsten oh (ketone) and androsten ol (alcohol). There are 50 times more of them in men's sweat (since there are dozens of times more androgens in the male body). But do they work on women? For some reason, none of the articles on this topic mention that the experience ended in an orgy…
And the vaginal secret of women contains copulins, the monkey analogues of which literally "drive crazy" male rhesus macaques. These compounds were used in the production of "sex perfumes" to attract the opposite sex.
Unfortunately for the emboldened losers of the love front and eager for new victories of the Casans, experiments have shown that androstenone sprayed in the air does not affect the sexual desire of women in any way, although they prefer to sit in chairs sprayed with it. There is also evidence that androstenone improves the mood of women and makes them more calm and confident, but no more.
The effects of copulins on human males could not be identified at all. Maybe, in addition to copulins, there are still some secret substances in the vaginal secret of women? In favor of this is evidenced by the ancient recipe of the "French folk pheromone" that has come down to us: when going on a date, it does not hurt to hold your finger first there, and then behind the ear. Although, perhaps, even in this case, pheromones do not act in a rough and animal sense, but simply associative connections in the brains of males of the genus Homo…
Unlike insects or tadpoles with their short thoughts, instinctive reactions to pheromones in mammals are not so pronounced, and manifest themselves with the participation of higher nervous activity. A moth glued to a slide will, no matter what, flap its wings at the smell of a butterfly of its kind, and a well-bred male can be dissuaded from participating in a dog wedding by shouting "fu!" and "to me!". In a person with his underdeveloped sense of smell and hypertrophied brain, it is very difficult to detect the influence of odors on behavior. It is not even known whether we have a special organ for the perception of pheromones proper.
There is no smoke without fire
"Just" smells are perceived by animals in the same place as humans – by the olfactory epithelium in the upper part of the nasal cavity. But in the life of animals, pheromones play such an important role that reptiles and most mammals have a special, so-called vomeronasal, or Jacobson organ for their perception. The long processes of its neurons do not enter the main, but the additional olfactory bulb, and signals about pheromones enter the higher parts of the central nervous system in parallel with information about ordinary odors (in the lower figure).
For a long time it was believed that the germ of the vomeronasal organ, appearing in human embryos, atrophies during intrauterine development. In fact, this organ is also present in adults. It was first described in the early 18th century by a Dutch doctor who operated on a soldier with a facial wound, but this discovery was undeservedly forgotten for a long time. More than a century later, scientists discovered and described the vomeronasal organ in various animal species and only recently proved its existence in humans.
The human vomeronasal organ is represented by a small depression located at a distance of 15-20 mm from the edge of the nostrils. Approximately 80% of people have such pits in both nostrils, the rest have only one. But in humans, it was not possible to find either an additional olfactory bulb, nor specialized nerve fibers coming from the vomeronasal organ, nor the fundamental possibility of transmitting nerve impulses from the cells of its epithelium up the instance. But, despite the lack of evidence of specific human perception of pheromones, there is more and more evidence that volatile substances released by other individuals of the Homo sapiens species, not even recognized as odors, play a significant role in our lives.
In 1998, the American physiologist Martha McClintock found that applying the axillary secretions of one woman to the upper lip of the second synchronizes their menstrual cycles. This discovery explained the coincidence of the menstrual cycles of women living in the same apartment or room that McClintock had noticed earlier. Further work has shown that the smells of men also affect menstrual cycles and ovulation time in women, and the smell of sweat of sexually aroused men excites areas in the brain of women responsible for sexual behavior and pleasure.
Thus, despite the lack of clear scientific evidence of the existence of human pheromones, it is easier and more logical to write off not only the facts described above, but also a number of observations made a very long time ago. For example, the fact that girls living in the same apartment with their biological fathers, puberty comes a little later than girls deprived of the company of their fathers. A slight delay in puberty of girls is also observed when visiting specialized girls' schools.
Official version
To date, it is generally believed that human pheromones still exist and are fragments of sex hormone molecules and, possibly, other molecules secreted by human sweat glands and modified by bacteria living on the skin. The uniqueness of the microflora of each person ensures the individuality of the bouquet of the smell exuded by him, including the pheromone fragrance, which practically has no smell in the everyday sense. That is why an almost blind baby recognizes his mother, and adults unmistakably choose from piles of clothes things worn by their close relatives and loved ones.
The largest number of pheromones is released in the genital area, armpits, crown, nasolabial folds and nipples of the female breast. This explains the irresistible craving of men for women's hair and breasts, as well as the passion of both sexes for kisses and close hugs, which allow you to literally carry away a piece of a loved one in the form of his pheromones, dissolved in the secret of sweat and sebaceous glands.
Since morality appeared in human society, people have tried in every possible way to reduce the effect of pheromones by covering their bodies with clothes. For a reason, it has long been prescribed in many cultures for married women to cover or even shave their hair, which provides an extensive surface for the evaporation of pheromones secreted by the scalp. It is interesting to note that such traditions are especially common in hot climates, where people not only sweat more, but also the strong half of humanity has a hot temperament.
Today, such products of civilization as sanitary pads, antiperspirant deodorants, antibacterial soaps and hair sprays effectively help us in the fight against pheromones. Perhaps they are partly the reason for the difficulties experienced by many modern people in romantic affairs. By the way, to smell the fresh secretions of sweat glands for the human nose is an impossible task. By itself, sweat practically does not smell of anything, and what deodorant manufacturers are so selflessly struggling with is the smell of metabolic products of the normal microflora of the skin, mainly two types of lactic acid bacteria: Lactobacillus pes–odoris and L. ala–odoris (pes in Latin – leg, ala – armpit). So giving up washing and hygiene products is not an option: the smell of an unwashed body will outweigh a slight increase in the pheromone signal.
What to do?
Unfortunately (or, rather, fortunately), the idea of a universal pheromone to attract the opposite sex is untenable, and a certain effectiveness of "sex spirits" can be explained by the suggestibility of their consumers and the strengthening of their self-confidence. Even if such a universal pheromone were found, it would be useful only in finding a partner for one night.
If the purpose of the search is a serious relationship, the bait should be your own unique fragrance, which is better not to drown out with pungent odors, but to emphasize with a light pleasant perfume, the aroma of which will make others sniff and, perhaps, feel something previously hidden from them. It should also be remembered that the molecules of human sex hormones are much larger and heavier than the pheromones of butterflies, which greatly limits the radius of their action. Therefore, if you intend to seduce someone, do not miss the opportunity to exchange a friendly kiss, whisper something in your ear or come up with something else, while trying not to violate your personal space for a long time. Such an exchange of pheromones will not only give you pleasure, but also allow the object of seduction to fully appreciate your attractiveness.
Perhaps pheromones (among other, more obvious aspects) play a role in the old folk way of dating at dances. During fast dancing, the heated body actively releases odors, and slow dancing is a unique chance for a "pheromone dialogue".
In any case, both the actual smells and pheromones for human beings are only an auxiliary tool in the difficult task of finding a partner. At least because the brutal macho (mouse–dominant male) in most animal species, including humans, benefits for family life – like a goat milk.
Evgeniya Ryabtseva,
portal "Eternal youth" www.vechnayamolodost.ru
The journal version of the article was published in Popular Mechanics No. 5-2009
13.05.2009