Why armadillos don't have ulcers (but would if they had a prefrontal cortex)

That's real good wood there.

In his celebrated book on animals and stress, Robert Sapolsky, professor of brainiosity and brain serums at Stanford University, who looks perpetually like a feral he-moth, exposed a primary link between memory, which collectively we class as an asset, and stress-related diseases. According to Dr. Crazy Hair, when a zebra in the wild--or any other animal, it doesn't really matter--gets spooked, chased, walloped, nearly digested, it, like any thinking, feeling creature, goes a little berserk inside. Its endocrine system floods the body with stress hormones, causing the pupils to dilate, blood and oxygen to rush to the muscles and vital organs, and decisions to delegate to the faster, more obstinate sympathetic nervous system, which doesn't want to hear any of your dumbass, rational excuses for not running around in circles until you collapse. From an evolutionary perspective, it makes a lot more sense to flee first and not ask any questions now or later. Never. Just get your ass moving. If the threat is overestimated, no harm done but a few wasted calories; if underestimated, you dead. Better to take the first alternative and risk looking foolish.

This predilection to flee or fight before considering the options is the reason we survived our many, many predators to evolve into the shuffling, self-gratifying apes that we are. We owe our very lives to its no-thinking approach to problem-solving. In fact, it works so well that every mammal on earth exploits it. Why do my rabbits always assume it's a threat--every windblown leaf, every drip from the faucet--until much later, after copious, superfluous, ridiculous evidence and demonstration? (And even then, they're still skeptical.) Why do stray cats hiss at you and not lick your hand? Why do monstrous hippos gouge and trample a ton of people every year in Africa? Stress, man. The brain releases high levels of adrenaline and noradrenaline into the bloodstream, and for a few minutes the world goes Apocalypse Now. That's a good thing; that's what keeps animals alive.

Unlike other animals, however, for whatever reason we sprouted a squishy new part of the brain mass that, among other novelties, enables us to anticipate future events whose imminence is not indicated in any way in the present environment, as well as to return to past events whose relevance is not confirmed in any way in the present environment. It also allows us to infer thoughts and intentions in other animals, and even to populate inanimate objects with thoughts and intentions. In its tissue lies the origins of worship, or imagination, or art, and of delusion and psychosis. Call it the prefrontal cortex. It's a neat innovation.

Unfortunately, in addition to being prolific and potent, it's continuously online, and anyone who's stayed awake, either by choice or force, for a few days or weeks without rest, knows the endgame of uninterrupted vigilance: paranoia. You read patterns where there's only noise; chance looks more and more purposeful. Your higher mind goes haywire, which trips the alarms on your lower, reptilian mind, where the stress hormones percolate. The result is a sympathetic nervous response to no threat. And in the absence of a threat, the body, searching for a solution, encircles itself in ever-constricting psychic string. Now the tangles from the string become a danger, which triggers more stress, which rings the bell, which stimulates action with no plan, and, eventually, if this feedback loop runs long enough, the system breaks down. You get sick. Your immunity fails. You believe you're assailed. You've imagined yourself right out of living.

In its natural environment, which is the drab mammalian brain, with its bouncing limbic precocities, stress is a miracle-maker. By supercharging their little rodent legs (or thunderous equine powerlimbs), adrenaline and its cohort of hormones essentially triple the speed, strength, and fight of the threatened organism. Then, having served their purpose, the hormones linger in the bloodstream for a few minutes, as the animal trots and kicks and growls its way back to normalcy, before getting expelled through the glands or bladder. (This afterlife of adrenaline is the reason why attacked animals that survive will continue to "run off" their trauma once the threat passes.) With its body returned to a neutral, alert state, its hormones in equilibrium, the animal simply forgets what happened. It has no need to remember. If the threat returns, the same sympathetic response will occur and life will go on or it won't. Trauma is not something you learn from.

Except in people. Take me, for example. Panic and anxiety, which are the high-strung cousins to all the other stress-related diseases studied by Sapolsky in his hordes of baboons (he studies baboons), basically trap the brain in a chronically malfunctioning stress response. What new component closes the circuit? Why does this disorder seem to afflict only the socially ruthless, hypersexed, politically keen greater apes, and we the greatest of all? Because we plan. And plan and plan and plan. And scheme. And remember. And remember and remember. Our thoughts are gifts and guardians, but they are also blights and assassins. Thanks to our prefrontal cortex, we can remember that morning when our favorite rabbit jumped on our head, and we can inhabit in that moment as viscerally and truthfully as though it were now. Also due to the cortex we can compulsively re-experience the horror of nearly dying; we can degrade our lives into a shadowland of reticulated torments, torturing the present with false certainties of past pain and future fear. We have, with our battery of imaginings, the power, as did Boethius, to rot in prison while in our hearts we dwell in asylum; or, with our stomachs full, our desires sated, our ruin averted, to yield our bodies to the relief of fine beds or chairs, with contented conversation all about us, and good company in our grasp, while in our minds we writhe in terror of anticipation, or cower at remembrance.

Thinking is not necessarily a good thing. As speculating beasts, we pride ourselves on our intelligence, believing mental prowess to be the pinnacle of evolutionary tinkering. How could it not be? After all, it is we, homo sapiens sapiens, and not crickets or turtles that re-terraformed the planet, manufactured light from particles we can't even sense are there, invented speech, and walked on worlds other animals are not even aware exist. We also, to some extent, understand those worlds, which is, in my opinion, a far greater achievement than walking on them. But that estimation is a very human way of valuing. What makes a species successful? Bacteria outnumber us by numbers so large I don't even have the names for them; they also flourish in more diverse environments. We, on the other hand, teeter on the edge of destroying both ourselves and all our mammalian relatives, as well as most of the rest of life on earth. And it's our thinking that got us there.

Most of you know that I walk a lot lately. And a lot of my walking is at night, because after the sun goes down the temperature drops from burst-you-into-flames hot to uncomfortably okay. Also, in the late hours strange animals roam the city, and I like to look at them. Twice this week I've met armadillos. Both seemed blind as hell and mostly uninterested in anything except digging for insects. But the one I met last night, in addition to teaching me that armadillos can stand on two legs if they choose to, inspired this overlong tirade by catching sight of me, scrambling to a safe distance, and then completely forgetting about me. I, by contrast, after stumbling into a giant, staring, unclassified monster, would still be shivering in the corner, scanning for signs of it in the wallpaper, the toilet water, inside my pillow. Not everything about being smart is helpful. As I get older, and stranger, and more anxious, I catch myself thinking, Socrates was wrong. True, living ethically, wisely, and peacefully does require that you understand certain things and to remedy your ignorances. But it also requires that you know the secret life of knowledge: that too much of it is a hindrance; that life is not a schoolroom lesson to be mastered; that even if I could, like some Platonic Hercules, deduce Truth and in that instant transform myself into pure Mind, like a vat of dry ice, I would not find myself in another, better reality but just this one. And I'd still be wrong. Because what if the whole point of living, of being a creature, a creating thing, is not to know but to be? I've already done that. I'm doing it now. With all my intelligence over that armadillo, I'm the one suffering. He, on the other hand, tiny and well-measured for his world, delights in his pleasures and hurts in his hardships, but he does not suffer. I'm no more real or alive or authentic, in some misguided Sartrean sense, than he is. If anything, it's he who lives the more honest life. His brain simply isn't capable of being this wrong, or deluded, or contrary. So if I see him again, I'll ask him: "sensible beast, what must I not know to be wise?"