Reminders for Humans is a monthly series that explores a natural phenomena, and how I’m applying its wisdom to my own human life. I’m a scientist by training, and a gushy poet by nature. Expect both.
“And the day came when the risk to remain tight in a bud was more painful than the risk it took to blossom.”
- Elizabeth Appell1
Reminders for Humans:
Agitation, while uncomfortable, necessitates action; requires that we move, change, respond.
For a long time, medicine considered itch to be a subset of pain. Modern research disproves this. They are independent neurological sensations- meant to communicate different messages to the brain, and compel different responses.
Many animals are observed in itching-scratching feedback loop behavior, usually at consistent times: when they are on the cusp of shedding, outgrowing, and molting into their next phase.
A friend of mine woke up a few weeks ago and needed to move to a new apartment.
Her lease wasn’t up. She wasn’t kicked out. It was something else.
On a morning like any other, she awoke to find herself with The Itch.
Last summer, I dropped everything on a Thursday to find a one room cabin in southeastern Colorado to escape for four days of silence, mountains, and green. I got The Itch.
Another friend, in the span of two months, quit his corporate job, sold his furniture, and bought a one-way ticket to another continent. He too got The Itch.
However and whenever it appears, The Itch accomplishes goals with an otherworldly efficiency. Given two options: doing what’s normal and socially expected of you; or scratching an idiopathic itch that is driving you nearly insane, what do you do?
You break the lease. You book it to the mountains. You take a year off to backpack Europe.
The goats have started shedding, which I only know because they’ve made it a habit to lean their entire body weight against the chain link fence of their pen, then walk slowly in one direction and another, like they are luxuriously side-swiping a row of parked cars, leaving tufts of fur in their wake. One after another, they slam themselves into the fence in a conga line. I’m sure it feels amazing. Every day the bottom of the fence bows out a little further like a pregnant belly. A pregnant fence belly full of hair. You get it.
The horses are shedding too, chunks of fur are all over the pastures. Every now and then I catch two of them grooming each other. Standing side by side, face to butt like the yin yang fishes, licking fur off each others’ backs.
And the chickens? It’s hard to tell. They’re always itching themselves and forever living in filth.
Regardless, when the winter coat is no longer necessary, it’s time to shed. And when it’s time to shed, it’s also time to scratch. It’s probably torture to shed your skin, molt your feathers, lose a winter coat hair by hair. Imagine how itchy!
But once you scratch it? Bliss.
My question this month is this:
When it comes to our inner, non-physical worlds, why does The Itch arise?
What is the big-picture purpose, biologically or metaphorically, of this specific kind of agitation? Since we are unduly obliged to obey it — a hack to the rationality otherwise encoded into our modern existence — what might the itch have to tell us?
The Science of Itch
It’s worth naming that, in this piece, I am focusing on the sensation of an acute itch, not a chronic itch - which is a much different and far less-understood phenomena that affects animals and humans through ongoing skin maladies and inflammation: psoriasis, eczema, allergies, idiopathic (unknown-caused) rashes, etc.
Acute itch does not last long. Acute itch points to a very specific place, right here, and a very specific time, right now. At which point, once scratched, it disappears.
Yet interestingly, while “itch is relieved by scratching, […] the neural mechanisms that are responsible for this are unknown.”2
For humans and animals alike, the sensation of itch evolved to accomplish a time-sensitive purpose: to dislodge or dispel something irritating the body. Scientists are still working to understand these complex neurological, somatosensory processes.
A 2016 article in the Journal of Cell Biology says:
“The average human is covered in 1.8 to 2.0 m2 of skin. […] With such a large surface area, a sensory modality we call itch has evolved to alert us to potentially dangerous external stimuli. […] Acute itch serves us well in guarding against environmental threats”3
After a mosquito bite, the body will respond by releasing histamine in the area surrounding it.
This histamine triggers the sensation of itch, causing us to intuitively scratch the area. It’s theorized that this reaction would be advantageous to ancestral humans intimately involved with the natural world - any number of irritants could be encountered and lead to potential illness. Scratching an area that became suddenly itchy would, for instance, dislodge any eggs or larvae that had been laid by a visiting spider; remove an insect before it could bite again; or scratch away plant residue that may be noxious.
“‘Our ancestors lived in a very pruritogenic world,’ Yosipovitch says, one full of itchy plants and bugs that posed a real threat. That threat explains the contagious nature of itching. ‘When we see the signal of someone scratching, we start scratching, too,’ as a kind of preemptive strike.”4
Scratching an itch has been compared to yawning, in that it appears to be a behavior that humans mimic in one another. Think about it. If you’re in a dense brush with another person, and they begin to furiously scratch at themselves, your body may subconsciously encourage you to do the same - to prevent or remove from your own body what’s already affecting your peer’s.
In their work to understand its biological mechanics, in recent years, scientists have corrected the long-held assumption that itch was a subcategory or cousin of pain.
Instead, it’s now clear that itch and pain are, biologically and neurologically, “distinct sensations.”
The authors continue:
“Early studies saw itch as a subset of pain, where sensory neuron firing frequency could distinguish itch from pain. However, more recent work points to a labeled line theory in which itch has a distinct population of spinal neurons that encode itch. […] Unlike the sensation of pain, where an organism will actively try and withdraw from an unpleasant stimuli, itch compels the affected to seek out the source and respond with a scratch.” (Source 3)
Itch does this via specialized “itch neurons” within the somatosensory system - a crucial part of the nervous system that perceives sensation, translates it into information, then sends it to the brain.
While itch can be ruthlessly uncomfortable if left unattended, this sensation resists being simplified into the larger category of pain; biologically or experientially.
It has much more complexity and intelligence to unveil.
Itch in the Animal Kingdom
Bison live in some of the coldest environments of North America, surviving the frigid temperatures of winter by growing a dense winter coat. When spring arrives and days become longer, the rising temperature triggers their shedding process - in which they rub their giant bodies against whatever they can find to dislodge the long, rough fur of their winter undercoat. They scratch their heads, shoulders, ribs, and flanks against trees and fences; and roll around in the dirt - a behavior called “wallowing”.
When mid-molt, birds routinely groom and pick out feathers - leading to patchy-looking appearances once or twice a year before their new plumage grows in. Horses do the same (but unlike birds, they don’t go partially bald.)
Wolves shed nearly 60-70% of their fur volume each spring, when they are “blowing their coat” - releasing and removing the undercoat of fur that allows them to survive sub-frigid temperatures for months on end. Unlike domesticated dog species, wolves tend to shed in a concentrated timeframe and process: tufts of fur pulled from their undercoat stick together and release in long, connected strands. It’s a much more efficient process than scratching fur off in individual strands over the course of months.
Snakes shed their skin once every few months, the process nearly identical each time it occurs, and critical for their continued growth and survival. They’ll begin by rubbing their head and neck on surfaces around them, to loosen the dead skin from their faces. Once the translucent, paper-like skin is separated, the snake slides its body forward through rough objects and textures - slithering the dead skin off inch by inch. In this video, a (truly gorgeous) snake muscles itself through the bark of a tree, moving and releasing the dead skin away scale by scale, leaving behind an exact-replica of itself.
The Itch-Scratch cycle is a negative feedback loop observed across species, appearing as both a one-off (a fly bites a horse, a dog scratches an ear) and consistent (like the weeks per year they spend shedding or molting.)
Of course it’s arguable whether we could ever know for certain whether all species experience the same sensation we’ve coined “itch”. Frankly, we can’t know for certain about any sensations that animals experience. We can only observe them and give it our best, scientific guess. But for argument’s sake, there is certainly some reason why they begin to engage in scratching behaviors.
I’d bet the reason a snake rubs up against rocks and tree bark, while it actively tries to release its dead skin, is because it feels good. Nature rarely does anything that has no benefit, that does not serve a purpose, or accomplish a goal. My belief, and the assumption of most biologists, is that animals scratch because they, like us, itch. That simple.
Though the name may connotate something bleak, a negative feedback loop is actually quite beneficial in most cases. The purpose of this type of feedback loop, in whatever system it exists within, is to maintain homeostasis: a balanced, neutral, healthy state. It’s self-correcting - the same basic principle behind how thermostats work, and how our body temperature regulates through sweating or shivering.
First, an undesired state occurs: an itch. Then, the response happens: scratch.
We reach the desired state: no longer itchy, and bigger picture, at a lower-risk state of being. Whether we’ve pushed away the insect, removed the inflammatory pollen, or scratched at undesired sensation, the process leaves us at a state of lower-risk.
This is an important takeaway. Our bodies are consistently monitoring themselves, and are, thus, the primary authority on subconsciously scanning for undesired states and initiating the process of fixing them.
And one highly-efficient methodology to do so is an itch.
Say what you will about this metaphor and how far I’m willing to stretch it, but I find it interesting that the figure of speech we’ve adopted for the nagging feeling of I need to change my life is “getting an itch.”
That when we feel called to do something specific, we’re “itching” to get going.
Nature shows us quite clearly that many living creatures experience this sensation on the precipice of something evolutionary: when they must molt, shed their skin, remove the extra burden of a winter coat.
When they are changing to be better-adapted to the environment around them.
Would it be such a stretch then if our subconscious, or call it our spirit even, may use this same approach when it’s time to make changes in our lives? Minor or major; a weekend in the mountains or a year-long trek.
I can’t be in this apartment for another month, let alone another year.
This job makes my skin crawl.
I’m itching to get up to the mountains.
Again I ask, given the option of doing nothing (otherwise known as - doing what’s socially expected of you,) or scratching an itch that’s driving you insane (the more common animal response), what do you do?
We are slaves to The Itch. And, at least in my experience, its acute arrival and resulting agitation of life has always been a net good, and has served me in the long run.
Even if she wanted to, my friend wouldn’t be able to pinpoint, rationally or scientifically, the final straw, the catalyst, the X-factor that one morning switched a group of reasons that have existed for years (neighborhood, rent, amenities) from an inert list of factors, to something otherwise unbearable to continue enduring.
Agitated is a term often used interchangeably with synonyms like annoyed, bothered, uncomfortable. While they have similar uses, they come from very different sources- their etymology paints two distinct stories.
Annoyed comes from the late Latin inodiare, to "make loathsome”.5
Agitated comes from the Latin root agere "to set in motion, drive, drive forward," or "incite to action; keep in movement, stir up."6
Being agitated, physically or emotionally, makes you move. Forces action. But being annoyed does not inherently, definitively, necessitate action, movement, or doing something about it.
A horse may be annoyed that, every year like clockwork, it has to remove its winter coat - but agitation (itching) is what forces them to scratch it off. The coworker that makes pointless smalltalk over the coffee maker is annoying; but the dull, grating agitation of waking up each day filled with dread to enter the building again is what forces you into a job-search.
Perhaps there is an inherent intelligence to the agitation of itch: that it is uniquely capable of getting us to move our lives around into shapes that better serve us; remove the extra weight; scrape away the dead.
Whether on our skin, or in our hearts. An itch usually has something to tell us.
Sources
Video Sources:
Horse shedding: @cordelia.edwards, TikTok
Wolfdog shedding: @yamnuskawdsanct, Yamnuska Wolfdog Sanctuary, TikTok
Bison shedding, wallowing: @bigballsranchsc, Instagram
“A wild snake shedding its skin, amazing snake behavior in nature”: Living Zoology, Youtube
Image Sources:
“Snake’s shed skin,” Shubhada Nikharge, Flickr,
“Bison, Spring's Shaggy Beasts,” Wild Idea Buffalo, wildideabuffalo.com
"Summer versus Winter,” Texas Wolfdog Project
“A wild snake shedding its skin, amazing snake behavior in nature”: Living Zoology, Youtube
“Destructive Creation: When Feedback Loops Go Wrong”, Janet Brunckhorst, LinkedIn
This quote has also, more popularly, been attributed to Anaïs Nin. After looking into it, it remains unclear who said it versus who popularized it. So, take your pick. I’m going with the underdog for today.
“Relief of itch by scratching: state-dependent inhibition of primate spinothalamic tract neurons”, Davidson et al, Nature Neuroscience (2009). Link
“The cell biology of acute itch”, Dustin Green, Xinzhong Dong. Journal of Cell Biology (2016). Link
“Annoyed”, Etymology Online
“Agitated”, Etymology Online