Spring is that time of the year synonymous with renewal and rebirth. It can also be the moment in which we rediscover one of our senses – smell – as we leave behind winter, which is cold and devoid of fragrances.
Perfumes and odours are everywhere, whether they are nice or unpleasant: the nice smell of a rose, the delicate perfume of a person you love, as well as repellent smells. But how subjective is the way we appreciate an odour? Is everyone attracted to specific and well-defined set of perfumes, or is our perception of smell something ultra-personal?
It turns out that perfumes might not only provide us a range of basic sensations; they might also be used for more sophisticated goals, like finding a good partner. MHC molecules are proteins found in the human body. Their major role is to present peptides coming from antigens to immune cells, but they appear to have a role in our sense of smell too.
A study was conducted in 1995 to test women’s preference for body odours of men. It showed that the perfume of a man with a different MHC is perceived as more pleasant compared to a man having a similar MHC to the woman.
In 2013, another study evaluated the ability for humans to recognize the modification of their own body odour. Researchers created MHC peptide ligands, and then gave them to the participants. Results indicated that they found a modification of their odour by a “self-peptide” more pleasant, as opposed to a modification with a different peptide. This indicates that we would prefer our own scent on ourselves. It might also explain why different persons with common MHC peptides appreciate similar perfumes on their skins but dislike them on other individuals.
That same year, a study performed in Auckland demonstrated that, when testing volunteers for their sensitivity to compounds commonly found in food, there was a link between genetic make-up of the individuals and the perception of four of the odours including the smell of apples and of violets. Can this link be found for other perfumes? This question has not been answered yet.
There are several factors influencing our olfactory capacity. Science seems to be promising to elucidate some mysteries about this sense. In the meantime, take a deep breath, and try to catch the sweet and light perfume of spring.