The Great Forgetting
Evolutionary biologists say that smell is the oldest sense. Remnants of vertebrate olfaction can be traced back as far back as the Cambrian-era split from translucent lancelets. Before sight or sound, there was scent—a method of discerning the chemical composition of one’s environment. Think: invisible communication between fish. Pheromones to denote kin, mating season, and the proper time for migration. Molecules drifting from the dead to warn of recent predation, to say: Danger! Puff out your spines! Increase your body depth! Gather together and get aggressive!
Further down the evolutionary chain, there was the Jacobson’s organ, the evolution of forked tongues and elongated snouts to sense pheromones carried, not on water, but wind. An entirely new set of chemical messages was released from the anal and sebaceous glands, from mammalian ears, cheeks, lips, and paw pads. The earth was transformed into an elaborate map of interspecies territories, the borders composed of clawed trees, dried urine, and unburied feces.
How strange, then, that Homo sapiens underwent the Great Forgetting. Gone was the Jacobson’s organ, the ability to distinguish what was said by our mucus, spit, and sweat. Like our primate cousins, we entered the world illiterate. For 200,000 years, we sailed across oceans and trekked over continents unaware of the language that surrounded us at every step. How fitting—how utterly narcissistic—that even shrouded in ignorance, our bodies continued to broadcast, communicating messages to both predator and prey: I’m scared. I’m sick. I’m fertile. It’s my time to menstruate.
All of this is not to say that the human sense of smell is not well developed. Consider what remains of the ancient limbic system, the complex amygdala and hippocampus. One organ to process episodic emotion and another to encode spatial memory. Add scent to the mix and you get recall that is near-instant. What was once encoded and later lost to conscious awareness can resurface again. Think: the closest we can come to time travel outside of science fiction. A past recreated in the limbic system, one capable of reproducing both the prior space and embodied emotions.
Look for no further evidence than this anecdotal demonstration. A woman enters the kitchen where her partner is cooking fish. Before the sight of the discarded heads, tails, and shed scales, there is the smell, the overwhelming scent of trimethylamine, of already beginning to decay meat. The odor evokes a characteristic pattern of flight behavior: verbal agitation, a defensive posture, and retreat. The woman’s terror is not toward her partner or the frying fish but to a remembered threat, a visceral body-memory dredged up from the past. The olfactory cortex sparks the thalamus sparks the limbic system, and the woman is eight or seven or six again, forced to choke down her grandfather’s badly-butchered trout. She can taste the rancid flesh, feel each sharp bone pass through her esophagus, hear her grandfather say, “You don’t leave this table until you’ve finished.”
Understand: with smell comes nearly every other sense.
So, what is said woman to do, this human with her overactive limbic system, with her lack of a Jacobson’s organ to distinguish tasty meal from dangerous menace?
Perhaps the answer isn't a desensitization but a sort of tuning in, a regression back to that simple lancelet. To the social learning exhibited among fish, the cooperative empathy ingrained in their far less complex cortexes. Imagine: partner, parents, and therapist working, not to forget or suppress the woman’s anguish—to distance the mind from the body it undoubtedly inhabits—but to remember what was once. To listen and observe, but—most importantly—to simply sense. To understand the makeup of one’s environment. To learn to recognize and intuitively respond to the woman’s distress. So that allies might say with their bodies, regardless of ability to identify the pheromones present: