The Fascinating Psychology of Scents and Smells

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When it comes to COVID-19 testing, there’s a new leader in the pack. And he goes by the name Cobra.

Cobra, a Belgian Malinois, along with his partner, One Betta, a Dutch Shepherd, both work at Miami International Airport as the first-ever COVID-sniffing dogs. In double-blind trials, they proved to be on par with most lateral and PCR tests, accurately detecting the virus between 96 to 99 percent of the time.

As remarkable as Cobra and One Betta’s sniffing skills appear to be, they aren’t exactly new. For years, dogs have been successfully trained to detect a variety of human diseases, including cancer, diabetes, tuberculosis, and malaria—purely through smell. That their brains are 40 times more devoted to analyzing scent and their noses contain more than seven times the amount of olfactory receptors compared to humans might have something to do with it.

Still, while we, ourselves, may never be able to smell if COVID is in the air, our own olfactory capabilities are nothing to scoff at. In some ways, we even outperform canines and other talented scent detectors in the animal kingdom.

Humans are attuned to bananas—rather, the smell of bananas.

Research has found that humans are just as skilled as dogs and rabbits in detecting the main odorant in bananas (amyl acetate) and more sensitive to picking up certain odors in human blood and urine than mice. Evolution deserves the credit for these scent sensitivities as humans, like other animals, sharpened their olfactory senses in accordance with their lifestyles. It’s why dogs are more attuned to carbolic acids, which are found in the body odors of many dog prey, and why people are better equipped to detect odorants from certain fruits and flowers.

Sense of smell reflects your health.

We know that one of the symptoms of COVID is losing your sense of smell. But an inability to smell has been linked to other health conditions, too, including depression, schizophrenia, and Parkinson’s disease. Some research suggests that a declining sense of smell portends aging or sickness. Results from a study of elderly people (71 to 82 years old) showed that those who had a weak sense of smell had a 46 percent higher risk of mortality in the next decade than those who could smell normally.

Smells are extremely effective at triggering memories.

Among the five senses, smells tend to rank last in terms of popularity, but a 2021 study at Northwestern University found that our sense of smell holds the strongest connection to our memories. Again, this goes back to evolution. As our brains expanded, our other senses (vision, touch, hearing) re-routed how they connect to our hippocampus, the brain’s memory storage, while our sense of smell retained its direct connection to it.

You can smell like urine or vanilla to different people.

OK. So this only applies if you’re one of the select (un)lucky people who can actually smell androstenone, a chemical in testosterone, which is a key ingredient in male body odor. In 2007, researchers at Rockefeller University studied the DNA of those who could successfully sniff out androstenone in a lab test. Essentially, they learned that androstenone could smell either pleasant (vanilla) or unpleasant (urine) depending on the smeller’s genes or odorant receptor type, which is composed of different amino acids.

And finally, if you do find yourself losing your sense of smell, there are science-backed exercises to help get your nose back into shape, such as sniffing as many different scents as you can. Sommeliers apparently practice this method to prepare for their exams. There are even kits you can buy which contain dozens of vials of liquid aromas of common wine notes (think grass, lemon, smoke).

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