Pheromones are volatile, odorous substances which are released by one animal and detected by another, causing some sort of physiological reaction. These reactions can manifest themselves in a variety of different ways: some pheromones modulate sexual activity, some affect aggression, some play roles in territory marking, and other pheromones have similarly diverse effects on the target animal. Pheromones have been demonstrated in a very large number of organisms ranging from amoebas to fish to mammals, including primates. However, the question of whether human olfactory signals exist has been a question of much debate and few definite conclusions. In this paper I will look at some possible examples of odor signaling in humans.
Mammals of all sorts use olfactory signals to indicate willingness to copulate, define territory, mark their young, and signal aggressive intent. These processes can be seen in many animals used as models for human systems, including rats, monkeys (both Old World and New World), hamsters and mice. The fact that pheromones are important biological signals in a plethora of other species indicates that the possibility of human pheromones should not be discarded lightly.
Although humans generally rate olfaction as their least important sensory modality, we still spend billions of dollars, years of our life, and a considerable amount of effort to modify the way we smell (at least in industrialized countries). These efforts typically include scrubbing with deodorant soaps and scented shampoos, applying deodorants to those parts of our bodies we feel need deodorizing, and finally applying perfumes and sprays to replace those natural odors we just discarded down the shower drain.
A pheromone is a chemical an animal produces which changes the behavior of another animal of the same species (animals include insects). Some describe pheromones as behavior-altering agents. Many people do not know that pheromones trigger other behaviors in the animal of the same species, apart from sexual behavior.
Pheromones, unlike most other hormones are ectohormones – they act outside the body of the individual that is secreting them – they impact a behavior on another individual. Hormones usually only affect the individual that is secreting them.
Pheromones can be secreted to trigger many types of behaviors, including:
To follow a food trail
To tell other female insects to lay their eggs elsewhere. Called epideictic pheromones
To respect a territory
To bond (mother-baby)
To back off
Sexual attraction may be more science than seduction, making “chemistry” between people a reality. National Public Radio reported that scientists in 1959, first identified chemical triggers sent and received by living organisms, and named them pheromones. Pheromones are chemicals sent from one body to another, within the same species, and are used to communicate danger, marking territory or attracting a mate. The good news is you may have control over how you attract a mate by the foods you eat.
Pheromone research in humans has primarily focused on natural chemicals and odors that are concentrated in the skin, the largest organ of the human body. According to the December 31, 2008 “Journal of Neuroscience,” an MRI study of female brains, conducted by Dr. Chen from Rice University in Houston, showed a strong, unconscious response to male sexual sweat vs. little to no response to other types of male sweat, such as through exercising.
Gustav Jäger (1832-1917), a German doctor and hygienist is thought to be the first scientist to put forward the idea of human pheromones. He called them anthropines. He said they were lipophilic compounds associated with skin and follicles that mark the individual signature of human odors. Lipophilic compounds are those that tend to combine with, or are capable of dissolving in lipids.
Researchers in the University of Chicago claimed that they managed to link the synchronization of women’s menstrual cycles to unconscious odor cues and food cravings. principal kinds of pheromones:
Releaser pheromones – they elicit an immediate response, the response is rapid and reliable. They are usually linked to sexual attraction.
Primer pheromones – these take longer to get a response. They can, for example, influence the development or reproduction physiology, including menstrual cycles in females, puberty, and the success or failure of pregnancy. They can alter hormone levels. In some mammals, scientists found that females who had become pregnant and were exposed to primer pheromones from another male, could spontaneously abort the fetus.
Signaler pheromones – these provide information. They may help the mother to recognize her newborn by scent (fathers cannot usually do this). Signaler pheromones give out our genetic odor print.
Modulator pheromones – they can either alter or synchronize bodily functions. Usually found in sweat. In animal experiments, scientists found that when placed on the upper lip of females, they became less tense and more relaxed. Modulator hormones may also affect a female’s monthly cycle.