The Stench in the Air
Let’s face it, everyone stinks. Whether it’s from excessive exercise or from an overly liberal use of the perfume bottle people smell. But here’s an idea–it’s unusual for people to have an aversion to body odor because the rest of the creatures in the animal kingdom don’t. If you’ve seen dogs sniff each others’ butts, you know smell is very important for animals. But do we embrace our inner stinkiness? No way! We scrub until our skins are raw and then douse ourselves with deodorant, perfumes, cologne, and body sprays so we don’t smell like ourselves anymore.
According to Lyall Watson in Jacobson’s Organ and the Remarkable Nature of Smell, despite our obsession with the state of odorlessness, much of our social interaction is governed by our noses. It is not just smell we’re talking about here but our pheromone perception–a “sixth sense.” The Jacobson’s Organ, pits of sensory receptors located in our nostrils, was originally considered vestigial and useless by anatomists and physicians. But this is not the case–like in other mammals, it’s functional.
Experiments showed that neurons from the Jacobson’s Organ fired impulses to the brain after being confronted with human pheromones secreted by the skin. It’s even possible that the removal of the Jacobson’s Organ may severely impair one’s perception–how can one function without sensing, somehow, the invisible social cues other people emit? Without smelling other people’s true intentions, one might become positively paranoid and schizophrenic.
In evolutionary terms, the sense of smell is primitive. It’s only quite recently that we primarily maneuver around using vision or even hearing. In mammals, smell is primary for interaction–i.e. scent marking for territory, signaling for mates, and even for self-defense. Studies with rodents revealed that scent is essential in normal mating behavior and mother-young bonding. So it is not so wild to conjecture that humans use these same mechanisms to signal to each other even if we have many times less olfactory neurons than say, the pet dog.
This would explain all those results from experiments involving separating men and women via sniffing dirty t-shirts, why people prefer certain perfumes over others, why women living in close quarters synchronize their cycles, and how even strangers can pair mother and child after examining random clothing. Sometimes, we might intuit something even when we don’t noticeably detect an odor. Instead, it may be that how we process the olfactory information we receive rather than the quantity that matters.
Jacobson’s Organ is in the form of an extended rambling essay, loosely organized on the seven categories of smell defined by Carolus Linnaeus–the same man who introduced the system we use today for naming species. Compared to other popular science books, this one has a far more colloquial feel. I didn’t even realize I was reading about experiments except in hindsight.