For a long time, the nose was shunned. Because smell would be the remnant of an animality that man often prefers to forget. But in his book Through the tip of the nose – An intimate history of smells
, the author Sarah Bouasse gives it back its nobility, in the light of scientific and instructive explanations, which her work as a journalist specializing in odors and perfume has allowed her to accumulate. But also touching personal anecdotes, which reek of childhood.
Here are six little-known facts about smell that she highlights in her book.
We can have olfactory experiences even before we are bornYou might think that, nestled in its mother’s womb, the baby feels nothing of the outside world. Nay: between the 4 eand the 6 e
month of pregnancy, the fetal nostrils open and thus allow the circulation of amniotic fluid essential to its development.
And in addition to nutrients from the mother’s diet, this liquid is loaded with odorous substances. The baby can therefore have olfactory experiences before even setting foot outside!
Man is (almost) capable of smelling like a wolf (at least, if he wants)
We often tend to contrast animals and their phenomenal olfactory abilities with humans and their poor noses. But the human sense of smell is far from being underdeveloped: 3% of our genome is in fact dedicated to the olfactory receptors responsible for our perception of odors. Humans could also distinguish a billion billion different scents, according to a study published in the journalScience . Furthermore, another American experience, published inNeuroscience
, demonstrated that 21 human subjects out of 32 managed, blindfolded, to find the trail of a fragrance in a meadow. Enough to (almost) overshadow the canines.
But you still need to educate your nose and put intention into it… “When we train ourselves to pay attention to odorous information and process it consciously, the neuronal tissues will become denser, and it will then be much easier and reflex to name odors. Humans have enormous room for improvement,” analyzes Sarah Bouasse. And there is no nose superior to another, insists the passionate journalist, humans being “all equipped with the same organ”. Perfumers therefore have no particular predisposition!
Smells say a lot about us…
Clothes don’t make a monk, but maybe smells do. Indeed, in her work, the author recalls that there is an important identity and sociological dimension in smells. “They crystallize a lot of factors in our lives, such as where we live, the culture we come from, what we eat, whether we have a pet, an illness or whether we smoke. Even the choice of a detergent can reveal an environment, an intention,” explains Sarah Bouasse.
Also, each human being has their own smell, which is determined, among other things, by the genetic code and the bacteria present on the skin. It is then impossible to pass incognito in front of the sharp noses!
After a while, you no longer smell your perfume or the smell of your house, and that’s normal.
It’s happened to us all: overspraying perfume because you can’t really smell it anymore, or coming home after a two-week vacation and discovering (often with perplexity) the smell of your house. This has a name, olfactory habituation.
And it’s scientific: when the nose is stimulated by continuous olfactory information, the perceived intensity gradually decreases until it disappears. The phenomenon is not only applicable in the long term. During a simple metro journey, it is possible to no longer be able to smell the odors present in the train. At our expense…
There is no such thing as a “pure” smell
And yes, an odor cannot be “pure”, in the sense that it cannot exist, for us, outside of its context. The latter can firstly be personal, by awakening emotions or specific memories – Proust, with his madeleine story, proved this to us. “Memories that are made through smell are anchored much more deeply than those with the other senses. We can forget faces, entire episodes of our lives, but a smell that mattered at a given moment will be there forever,” the journalist deciphers. And the science backs it up: Humans can remember smells with 65% accuracy, compared to 50% for visual memories.
This is also why we sometimes begin to appreciate even strange smells (petrol, markers, parking, etc.), because they bring us back to positive sensations and memories.
Finally, there is the cultural context that plays a role in the perception of an odor. For example, the scent of a good French cheese will be pleasant to us, will arouse our appetite, while that of a pair of sports shoes will arouse our disgust. However, studies prove that these smells are very similar.
We feel better in the countryside
Our sense of smell is better in the countryside and, unfortunately, this has nothing to do with the sweet smell of flowers and hay. In fact, the polluted air of large cities can generate “inflammation of the olfactory epithelium, a nasal mucosa, which reduces our detection performance,” Sarah Bouasse tells us. But city dwellers can rest assured: certain olfactory receptors in the inflamed area regenerate every two to three weeks. So, we go green for a while, and it starts again!
Through the tip of the nose – An intimate history of smells(Éditions Calmann Lévy) by Sarah Bouasse, 212 pages, 18.50 euros.
