Everyone knows that perfume smells good (well, to most of us, anyway). It’s about as much of a truism as, “The sky is blue,” or, “Carol Baskin killed her husband,” (c’mon, we all know it).
But have you ever wondered why perfumes smell good? What is it exactly about them that pleases our upjumped primate brains? Why do some things smell good, and others bad? And what role, if any, does individual preference play in it?
Our responses to smells depend upon a variety of different factors. Perfume smells good because of a conditioned, positive emotional attachment to its ingredients. Our scent preferences are also influenced by our instincts – some smells are instinctively good or bad.
Want to know more? Let’s take a closer look at the science behind our love of sweet, sweet perfume.
What Are Smells?
Imagine this: the air all around you is filled with tiny, imperceptible odor molecules. These molecules make up the smell of everything.
The yummy scent of a banana, for instance, is not represented by a molecule labeled “Banana Smell”, but is instead composed of a host of different molecules, such as amyl acetate and isoamyl acetate. These molecules combine together to create the scent profile that we commonly recognize as the “Banana Smell”.
Just like the Mona Lisa is made up of a hundred different permutations and combinations of color, so are the smells that we sniff each and every day.
How Do We Perceive Smells?
Knowledge of the exact procedure by which the human brain processes odor is still being developed. Relative to other areas of study on the brain, olfaction was largely left by the wayside until relatively recently. Nevertheless, a complete picture is emerging.
When we sniff the air, the lingering odor molecules in the air get swept up into our big ol’ nostrils. Inside our noses lies a sticky membrane known as the olfactory epithelium. Once the molecules land on this olfactory epithelium, they immediately begin to be analyzed by millions of tiny nerve cells called olfactory receptors.
These receptors send their analyses up to the boss in the olfactory bulb, a structure located in the front part of the brain which is responsible for keeping track of all things smelly. But even the bulb has a boss, so it passes on the olfactory receptors’ work to be cosigned by an area of the brain called the piriform cortex, which has an express line to the amygdala, the part of the brain responsible for emotion.
Finally, somewhere along the line (scientists aren’t sure exactly where), the numerous odor molecules are assembled, and the brain begins to perceive that assembly as a unitary scent profile. When we smell a banana, after all, we don’t say, “Ahh, amyl acetate and isoamyl acetate!” but rather, “Ahh, a banana!”
Scent, Emotion, and Memory
Science has shown that scent, emotion, and memory are intimately linked. Odor molecules pass through the amygdala, the area of the brain controlling emotion, after all.
Our judgement of what smells good and what smells bad is largely based upon our emotional responses to particular scents. These emotional responses begin to develop from a very early age – particularly, in the womb.
What mothers consume while pregnant can lend their odors to the amniotic fluid. Infants born to mothers who ate a large amount of lemon flavored foods, for instance, might show a predisposition towards lemon scents or lemon flavors. By the same token, infants born to mothers who consumed alcohol during pregnancy might show a preference to the smell or taste of alcohol later on in life.
Think back to your own life and the smells that comfort you. Some find the smell of cigarette smoke to be unpleasant, but it reminds me of happy childhood memories spent at my aunt or uncle’s house. When I smell cinnamon, I think of eating cinnamon buns for breakfast when I was a child, or of Christmas baking. When I smell Chanel No. 5, my mother’s signature scent, I implicitly think of her.
Perhaps more than any other sense, smell has a powerful hold on our emotions and memories. Our preferences and emotional responses towards certain scents begin to be shaped from childhood and continue to evolve as time goes on.
So, is there any smell that smells inherently good to the human brain? Science is still undecided on the matter, but the consensus seems to be: not really. Our responses and preferences towards certain smells seem to be largely learned.
What About Bad Smells?
You might be thinking – what about bad smells? Surely bad smells are bad to everyone, right?
There is truth to that idea, to a certain extent. Smells like old blood, rotten eggs, spoiled fish, or decomposing flesh are almost universally considered to be repugnant to humans. Scientists have argued that this response, while certainly influenced by emotion, owes a lot to our instincts.
The smell of rotten eggs, rich in the shtanky and toxic molecule hydrogen sulfide, might cause an instinctive wariness in us since it could make us sick. The same could be said for spoiled fish or burning flesh.
These scents serve as primeval warnings from our days of monkeying around on the savannah, still present deep within our brains.
But what about smells that are more, shall we say, subjectively bad? Stinky French cheese, for instance, ripe durian, Taiwanese stinky tofu, or even certain perfumes considered lovely to some and abhorrent to others? These are learned, individual emotional responses, often influenced by culture, rather than instinctual.
What About Perfume?
So, now that we’ve broken down how the brain perceives scent and how scent is influenced by emotion and memory, let’s return to our first question: why does perfume smell good (or bad)?
As we’ve seen, which perfumes smell good to you will be largely based upon your experiences.
If you have positive emotions towards the smell of lavender or vanilla, perhaps you will enjoy perfumes with those notes. If you use lemon floor cleaner, you might think that lemon-based fragrances smell like that and be repulsed. If you grew up in a time when men bathed themselves in Drakkar Noir and Brut, you might feel drawn (or repelled) by similar fragrances. Maybe powdery perfumes remind you of your grandma, or sporty fresh fragrances of your ex-boyfriends.
If you grew up in the Middle East, you will likely be more predisposed to enjoying strong fragrances with oud, rose, patchouli, saffron, incense, and spices. If you grew up in East Asia, you’ll probably prefer lighter, fresher, more floral fragrances.
And if you have no prior experience with perfumes, or are smelling something new and exotic to you? Guess what, any “new” perfume that you smell will be full of odor molecules you’ve been smelling your whole life. Even if they’re assembled in a novel manner, there’s still more than likely to be some odor molecules present in the formula which you’ve smelled before and have a scent memory associated with.
So why does perfume smell good? It all comes down to individual preference – your own history, your own memories, your own emotions, and your cultural background.
The Final Word
The mysteries of olfaction are still being uncovered by scientists.
It’s still not possible, and may never be possible, to confirm that the smell that you perceive is the same as what others perceive. How much of the smell of a banana is an objective fact and how much of it comes down to emotion?
What is the difference between the odor assembly that corresponds to a banana in our brains and our emotional response to that assembly?
Is there any difference?
And how much of an overlap is there between the banana that you perceive and the banana that others perceive?
Who can say?
But it is clear, insomuch as it can be clear, that our responses to smells derive from our emotions.
Whether a perfume smells good or bad comes down to your own scent preferences. These preferences are linked with your memories, emotions, and cultural background. Some smells, like rotting garbage, are instinctively “bad”, but for the most part, your responses to smells like perfume are unique to you as an individual.
