Why perfume conditions us when choosing a partner (and what it says about our immune system)

Evolutionarily and in different species, including humans, the pair is chosen to optimally complement our own genes, especially those related to the immune system.

This is intended to make our offspring resistant to more pathogens.

And here comes the curious thing: although in our species there are hundreds of different forms of genes that encode the immune system, in each person some of these variants participate in providing the own and particular natural aroma that we give off and accompanies us.

That is to say, body odor speaks directly about our immune system.

Back in the 90s of the last century, scientists from the Max Planck Institute carried out the so-called “sweat shirt experiments”.

They consisted of the girls smelling the T-shirts with which the boys, without having used perfume, deodorant or aromatic soap, had slept two nights in a row.

Thus they discovered that women prefer the smell of men than they have genetic variants of the immune system different from their own.

What’s more, the researchers also showed that genetic variants of the immune system influence the perfume ingredients that both women and men choose.

In other words, we select the perfume in such a way that it intensifies our own immunogenetic olfactory signal.

A few years later, a series of tests were carried out in which each participant was able to recognize a specific perfume: the one to which particles of their immune system that characterize their own body odor had been added.

And, of course, from the aforementioned, also they selected that perfume as their favorite.

From a neurobiological point of view, magnetic resonance imaging showed that, when each participant smell your own immune particles, a specific region of the brain is activated: the right medial frontal cortex.

And this is very interesting, since it indicates that humans also have a structure that helps us, taking into account the smell, to decide which partner to choose.

In other species, the responsible organ is the so-called vomeronasal organ; through it, pheromones are detected, for example.

In humans, this organ is barely developed and is not functional.

With this suggestive title, a scientific article has recently been published in which the influence of olfactory stimuli is analyzed, from delicate fragrances to bad smells, on the perception we have of others.

It indicates that there is a whole range of body odors that influence what we perceive of another person: if she is attractive to us, what her age may be, if she is stressed or suffers from anxiety, if she is ill and even personality traits.

In addition, both the presence of an aroma and the absence of a bad smell influence the confidence that each person has in themselves, which undoubtedly affects how attractive she is to others.

This brings us to the well-known importance of smell in the impression that we can give in a meeting or in a job interview.

Interestingly, men score worse to people who wear perfume or cologne, while women act in the opposite way.

In general, it is thought that we use a perfume to mask body odor and to please more.

However, it has been shown that it is the combination of perfume with one’s own body odor that generates the pleasant and personal effect.

Of course, in the fair proportion that we are sure to be able to find.

Grandma Matilde used to say: “Girl, that perfume smells better on you than it does on me.”

In this sense, we perceive as more pleasant a mixture of own scent with favorite perfume than your own scent with another perfume chosen at random, even if both fragrances are generally considered equally pleasant.

That implies that the use of a perfume goes beyond avoiding bad smell and that we choose the perfume that best combines with our personal scent.

Hence, as the experts say, the particular taste that everyone has to choose the perfume.

What if we don’t use perfume?

Perhaps the explanation is in that interesting phrase from the novel “Perfume”, by Patrick Süskind:

“What I coveted was the fragrance of certain people: those, extremely rare, who inspire love.”

* Francisco José Esteban Ruiz is a tenured professor of Cell Biology at the University of Jaén, Spain.

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