If you were asked to describe your perfect partner what would come to your mind? You might be able to picture their face, hair, and height. You likely could list off their best traits; maybe their career, status, and even favorite leisure activity. But you would likely be missing a key describing factor. The truth in our search for love could very well be right under our noses, quite literally in the air we breathe.
Our Sense of Smell (Olfactory)
Upon walking into the grade school in my district to exercise my right to vote, I was transported back into my second-grade classroom, the one in which my teacher rewarded us with M&M’s for performing well on tests. I could even almost taste the M&Ms.
It may seem funny how memories come to us at certain times (like when I visited the grade school), but during these times our olfactory is actually hard at work processing information. It seems funny to us that this type of thing happens because the olfactory processing isn’t conscious.
So, what exactly is the olfactory? Simply said, it is our sense of smell.
To quote Merlin Sheldrake, “The human sense of smell is extraordinary. Our eyes can distinguish several million colors, our ears can distinguish half a million tones, but our noses can distinguish well over a trillion different odors. Humans can detect virtually all volatile chemicals ever tested. We outperform rodents and dogs in detecting certain odors, and we can follow scent trails. Smells feature in our choice of sexual partners and in our ability to detect fear, anxiety, or aggression in others.”
Our noses are so strong they can even detect certain smells where the concentration is as low as 34,000 molecules per 1 square centimeter; this is equivalent to a single drop of water in 20,000 Olympic swimming pools.
For those that prefer the basic biology, as put by Britannica: The Olfactory system is the bodily structures that serve the sense of smell. The system consists of the nose and the nasal cavities, which in their upper parts support the olfactory mucous membrane for the perception of smell and in their lower parts act as respiratory passages.
In case you haven’t gathered, our sense of smell is pretty cool, much more so than we give it credit for. But the question remains, what does it have to do with love? For the answer we will look to pheromones.
What are pheromones?
Pheromones are chemical compounds exuded by an organism for the purpose of carrying messages between organisms of the same species.
Pheromones have been found in many different forms of life, from fungi to insects to pigs. These chemicals are transmitted through the air as a form of communication, and sometimes (but not always) they assist in summoning a mating partner. The make-up of these chemical compounds vary from species to species, and is not limited to a single compound per species (i.e., pheromone is a generic term used for a wide variety of molecules used as communication devices within a species).
Humans are suspected to be no different than other life forms in excreting and processing pheromones. However, our excreting and processing is a bit more nuanced, and thus is not yet understood to its full extent (which probably explains why most of the pheromone products on the market fail to make their users sexually irresistible).
The reason for the nuance in humans can be explained by our complex make-up. As we mentioned previously, our olfactory processing tends to by-pass our consciousness (such as in the example where I visited the grade school). Further, each person alive has their own individual “scent” make-up, no different than how we each have individual fingerprints, which you can imagine would complicate the ability to find a consistent compound that serves as a “sexual attraction perfume”. Regardless, these complexities do not stop scientists from trying, and some of the studies and findings can be found below (see: ‘Is there any proof?’ below).
For the curious souls, our individual “scent” make-up is known as the major histocompatibility complex (MHC). The MHC is a group of genes which code for proteins found on the surfaces of cells. The proteins help the immune system recognize foreign substances. These genes have an unusually large number of alternate forms which therefore produce an unusually large number of alternate forms of the protein, which as mentioned above, makes the MHC molecule make-up unique for each individual.
The MHC proteins also help to regulate the immune system, leading scientists to believe in theory that people might search for a partner with an immune system sufficiently different from their own, leading the pairs’ offspring to have an even more diverse immune system more inclined to fend off all of those nasty pathogens.
Is there any proof?
As you may know, all scientific proof starts with a hypothesis. The hypothesis is then tested, in the case of pheromones through different research studies. After enough testing is completed leading to the same result, we tend to call something a fact. The research completed in support of pheromones aiding in human attraction, including the studies outlined below, isn’t yet enough to call it fact. For now, you will have to theorize yourself, but I wouldn’t count the nose out in your hunt for a future mate.
- As summarized in an article from Time, one study was completed “involving well-worn T-shirts, women sniffed shirts worn by men and picked the one they’d most prefer to socialize with. They tended to select shirts from men with MHC genes that differed from their own.”
- Research published in the journal Psychological Science went one step further with the scent-filled T-shirts. Couples participated together in this study, by wearing T-shirts that their partner would later use as a pillowcase; the control group pillowcases were T-shirts worn by a stranger. The results of this study indicated people who slept on their partners scented T-shirt experienced an increase in quality of sleep approximately equivalent to the results provided by melatonin, a commonly used sleep aid.
- In another study, the smell of tears acted as an anti-aphrodisiac. Researchers collected the tears of women produced after watching a sad movie. Men then smelled the tears and lower levels of sexual arousal and testosterone were reported.
- Researchers in Israel observed that sniffing your palm after shaking a person’s hand helped learn about the person’s health and genetic compatibility. 
- Martha McClintock, famously accredited with the idea that women living together will have synchronized menstrual cycles (sometimes known as the “McClintock effect”), has also elevated the potential pheromones: androstadienone (AND), found in male sweat and semen, and, estratetraenol (EST), found in women’s urine. Though a recent study published in Royal Society Open Science failed to prove EST and AND were pheromones, Martha noted that the study likely oversimplified the nuanced abilities of the compounds. She continues to study how these compounds, as well as the scents we excrete from sweat might influence our brains.
The future of love
Will we soon find ourselves in a world where dating apps will allow us to include our scent profiles? I don’t doubt a scent function to be in the future of smart devices.
I also wonder whether pheromones could have an impact on long distance relationships, where sending your distant-lover one of your t-shirts might help to keep the relationship in-tact. Or maybe we will all have our own hoo-ha-scented candles like Gwyneth Paltrow.
Joking aside, it does seem to me no coincidence that the immune system (the same system that produces MCH proteins) becomes fully developed around the same age that we go through puberty.
The matter of fact is that there is more to love than meets the eye (or the ears). We quite literally breathe in molecules of one other when in close proximity, and those molecules likely assist the workings underneath our consciousness to find true love. Although, I suppose it’s up to you to smell for yourself.
 Example provided in Entangled Life by Merlin Sheldrake