Pheromones emitted from sweat glands play a role in sexual attraction, sexual repulsion, mother-infant bonding, and menstrual cycles. The olfactory epithelium is a thick yellow/brown structure, about one inch square, located in the upper nasal cavity of the human nose. Made up of olfactory receptors and glands, the epithelium is used as a tool to smell others’ body odor and pheromones.
Chemicals that produce odour pass through the olfactory epithelium to the olfactory bulbs, which contain biological receptors that detect the chemicals, and respond with an electrical signal transmitted to the brain by the olfactory nerves. The olfactory epithelium plays a large role in why humans are attracted to persons biologically rather than physically; this relates directly to the sense of smell and not physical appearance. Olfactory communication is common in all animals and in recent studies have shown that humans have this communication trait as well. This kind of communication happens subconsciously, and often influences a person’s attraction to another. A dependence on such olfactory cues has led to the enhancement of male body odour to influence female attraction.
Olfaction, therefore, transmits information relevant to human mate selection, through which men are capable of detecting shifts in women’s fertility. Pheromones are chemical messengers produced and emitted by the body that contribute феромони to interpersonal attraction. The two types of pheromones include signal and primer, each playing a distinct role in human behavior. Signal pheromones act as attractants and repellents; they are classified as short term behavioral pheromones. Primer pheromones produce long term changes in human behavior and hormone production.
Fa acts as an index for measuring developmental instability as it provides a clear indicator of the possible environmental and genetic stressors affecting development. It is thought that having a preference for a symmetrical face offers some adaptive value as such symmetry may signal an individual’s ability to cope with environmental challenges. Fa shares an inverse relationship with certain desired traits; a low fa is correlated with higher stress tolerance, larger body size in males, smaller body size in females, and higher facial attractiveness. Fa is detectable through the olfactory senses and it has a measurable effect on sexual attraction.
Significant cues may be found through body odour relating to a potential mate’s health, reproductive status and genetic quality and fa is one such cue as it is considered to be a marker of genetic and developmental stability. Women’s fertility levels shift dramatically throughout the menstrual cycle, so the period surrounding ovulation is extremely important because it represents the peak period of reproductive fertility. As conception is most likely to occur during a woman’s brief fertile period, evolutionary theories suggest that men possess adaptations designed to maximize their reproductive success during this period.