Just look at you pet: your dog or cat smells the behind of a member of his own species to determine if that is good mating material. But make no mistake. With us humans, scent plays an important role when we choose our companions. Napoleon apparently prepared his wife Josephine from his return from the front line, by letting her know: “Don’t wash yourself, I’m on my way!”.
Choices we make in our day to day life are influenced by fragrances and pheromones. As with animals, humans use scent to subconsciously message each other about fear, illness, or sexual arousal. We find it hard to find someone with a bad breath or a repulsive body odor physically attractive. These smells make us think of diseases and lack of hygiene. An experiment with worn T-shirts, showed that women have a strong preference for men with a different immune system. This could prove that we use scent to determine if a partner is qualified to contribute to a stronger offspring.
Animals emit pheromones to show that they are in heat. When we are attracted to someone, it is not something romantic, but merely a response to an animalistic smell. Despite the fact that we humans have about 5 million scent receptors, as opposed to 200 million with dogs, scent does play an important part. Humans are attracted to someone because of pheromones. When your nose catches these smells, a signal will go the part of your brains (the so called olfactory cortex). This part has a direct connection with the part of the brain that regulate primal instincts such as sex, hunger, thirst. There are less connections to the neocortex, the part of the brain that we use for reasoning and judgement. Smelling something leads to an emotional response, rather than rational behavior.
Research into human pheromones shows that women secrete vaginal hormones, called copulins, that have effect to sexual desire. Men also secrete pheromones. Smelling these pheromones can simulate the desire for sex. But scent can also effect attraction. We generally find nice smelling persons more sympathetic.
A researcher once sprinkled the chairs of a theater with 5 α-androstenone, a fragrance that is an ingredient of male armpit sweat. These seats were predominantly seated with women. The programs that were sprinkled were also taken by women. In other words, women are attracted to this smell, because they associate it with males.
Everyone that has ever read ‘Perfume’ knows that it is the ultimate dream of a perfume maker to develop a scent based on pheromones, that increases the attraction of the carrier. The opposite if often the case. Perfume and deodorant mask our body odor and makes it more difficult for us people to follow our nose when we are looking for a partner.
Decoy that is used in almost every perfume are thick scents like amber, musk, castoreum and civet. These smells remind us of sweat, genitals and feces, even though these are now more often synthetic. Only in very small doses we find these ingredients attractive, otherwise we associate it with urine and feces.
Medication, such as the pil, change our endocrine system and influence the smell (in this case) women secede. In the T-shirt experiment, it appeared that women using the pil, chose men with a similar immune system. That is something like looking at your nephew or brother as a suitable partner.