My readers, finding out I'm not perfect
Nails are a remarkable aspect of human evolution. Made of a single layer of hard alpha-keratin, nails are analogous to claws or talons. Most mammals have claws, which are rounded.
One of the features of primates is broad, flattened nails instead of claws. Many primates bite their nails to keep them shortened; onychophagia is the technical term for nail-biting and it's seen in chimps, bonobos, gorillas, and orangutans, althought not universally. Some chimps are bigger nail-biters than others.
It's also seen in macaques, which are not primates but "old world" monkeys. Old world monkeys include baboons and rhesus monkeys. Old world monkeys are most often distinguished from "new world" monkeys by the tail; old world monkeys lack truly prehensile tails. New world monkeys (such as capuchins and squirrel monkeys) have fully prehensile tails. But, interestingly, nails are also different among these two families. New world monkeys (cebids) have curved nails. Old world monkeys (cercopithecids) have flat nails that are more like a human's.
Nails are long been considered a defining feature of the human being, ever since 2,300 years ago, when Plato defined man as a "featherless biped," prompting Diogenes to run into the Academy with a plucked chicken, screeching, "BEHOLD! A MAN!"
...Plato added "with broad, flat nails" to his definition.
If Diogenes were alive today, his YouTube prank channel would be fire.
(Random fun fact: Plato could have instead includes the presence of chins. Humans are the only animals with chins. While pretty much anything with a mouth has a lower jaw, only humans have a bony jut coming out below our mouth. In all other animals, the lower jaw slopes down from the front teeth instead of projecting. It is unclear whether this trait serves any real purpose or whether it's a byproduct of genetic drifting.)
Robbie Rotten has long been known to be the pinnacle of human evolution by memers.
So why do we have nails instead of claws?
The short answer is, nails were more practical for the type of locomotion that apes were doing. For smaller animals, like squirrels, nails are sufficient to grip onto tree bark. But for larger primates, claws went out of vogue and instead we developed broad fingers designed for grasping. (Fingerprints, by the way, are a crucial part of primate fine texture perception. And the wrinkling of fingers in baths? That's also designed to help you grasp.)
Getting back to nails: they aid in the grasping of things not just by being flat and kind of out of the way, but they help deliver grip feedback by counter-pressure exerted on the end of the finger. This may be one reason nails only have a single stratum, unlike claws or talons, which have 2 strata.
In other words, apes developed with the concept of "grabby hands" in mind.
But evolution isn't really directional. Rather, it employs a guess-and-check method.
This led to some scientists questioning whether or not the last common ancestor of today's living primates had nails or claws on the ends of their digits. Current evidence suggests that our ancestors had lost claws quite early and developed nails, but that those nails were two-layered. This is a seriously big topic of scientific argument, one apparently confounded by the horrifically-named "toilet claw" that is present on lemurs and tarsiers. (It's a claw on the second finger used for head scritches and more recently has been called the "grooming claw," which is a lot less gross.)
Feel free to Google it. It looks kind of gross, too, to be honest.
Sorry, lemurs, but your feet are naaaasty.
But this post has wandered into speculative territory and roamed, as evolution does, fairly far. Originally, you recall, I began this post by saying I bite my nails.
I'm not special in this regard. About a third of people are nail-biters. This is a condition that has long been recognized as an indication or symptom of anxiety along with other body-focused repetitive behaviors. (For example, skin picking, aka excoriation disorder... another one that I have. Again, not surprising, since nail-biting and skin-picking have a high comorbidity.)
I think nail-biting is an interesting example of anxiety. It's very much, for me, at least, a "can't see the forest because of all the trees" scenario. When I bite at or pick at my nails, it's because there always seems to be a teeny-tiny imperfection that I'm trying to "fix." Ironically I usually end up making it worse. A lot of nail-biters tear off their cuticles for this same reason, the idea of an invisible hangnail.
(Side note about hangnails: the term "hangnail" might seem obvious. It's a little bit of nail that's hanging off, right? Wrong. Hangnail is a folk etymology of the Old English angnæġl (
agnail), from ang- (“tight/painful” - think of anguish or angst) + -næġl (“nail”). It has nothing to do with the nail "hanging.")
Just as nail-biting creates an anti-solution to a non-problem and, in turn, makes things worse, so does anxiety.
I find that if I can force myself to adopt a new perspective then I can often curtail my nail-biting habit. When I look at my nails critically, they're actually just fine and need no attention. Natural wear exfoliates just fine; there is no need to constantly be filing or picking at them. Nail-biting, as a habit, can be broken; body-focused repetitive behaviors are a result of poor impulse control, and while impulse control disorders are considered a psychiatric "disease," their treatment often comes down to modifying the behavior of the individual.
(Another side note: Rocko's Modern Life had an episode where Rocko breaks his nail-biting habit using a 12-step program. Except the program is actually a series of utterly ridiculous tasks and ultimately the way Rocko breaks the habit is by simply forcing himself to stop.)
As someone with a boatload of anxiety, forcing myself not to bite my nails was a hard-won battle. My father bit his nails, too, down to the quick. In the same way I shifted my diet at the beginning of this year, I have also stopped biting my nails. Which isn't to say I don't slip up often, especially when I'm stressed. But my nails do not resemble those of a nail-biter, something I'm proud of. Like maintaining a diet, breaking the habit of biting one's nails requires a lot of self-reflection, impulse control, and constant, vigilant mindfulness. Something I'm all about. I like to challenge myself to do better and work on self-improvement at all times, and I believe that nail-biting is a good example of a habit that's hard to break but not impossible. People with depression and anxiety all too often hear people say things like "just choose happiness" or "just don't worry about it." And we can't really help that. But at the end of the day, living a good life isn't about always being right, or avoiding drama, or not making mistakes. It's about handling those human challenges gracefully and with dignity.
I am a nail-biter and always will be, but by working hard, my nails look okay. There are others who don't have to think about it and who don't ever have slip-ups. But I can't live my life comparing myself to them. Everyone needs to live their life for themselves and ask, "Are my actions ones I will be proud of in the future? Am I saying and doing the things that help me reach my goals?"
Ultimately I think most personal growth stems from 1) the ability to self-reflect, and 2) the ability to control one's impulses.
Nail-biting is a good example of what it's like to live with anxiety. It's easy to give in to. It's hard to fight. But it can be done. And the first step is looking at your nails (or life) with a critical, logical eye and saying, "You know what? This is actually fine. I need to just let it be."
This doesn't mean you can "cure anxiety" just by wishing it away. But it means you can control the consequences of the anxiety and how (or to what degree) anxiety affects your life. If you're a nail-biter, you'll always be a nail-biter; you'll often find yourself picking at invisible defects on your nails. The question is, when you realize you're doing it, are you going to stop yourself?
Evolution didn't spend millions of years giving you those magnificent one-strum alpha-keratin nails just so you could bite them off. You're a primate, damn it. Be kind to your nails.
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