The beauty of stress

There is a broad popular conception that stress is antithetical to a well-lived life. That it is some outdated piece of evolutionary technology poorly calibrated to the mundane vicissitudes of modernity. That it should be avoided or reduced at all costs.

Rather, the well-adjusted person should be in control of their emotions, achieving some unspecified state of equanimous bliss in an unpredictable world---left unruffled by the everyday tensions that tug at us on our personal journeys to success.

This popular conception is nonsense.

Let me first set up this absurd perspective, using the kind of language most typically (and egregiously) used by people to express this idea.

¶The absurd conventional wisdom

I quote from this recent Atlantic piece:

Your emotions can seem out of your control at the best of times ... That can be blamed in part on biology. Negative emotions such as anger and fear activate the amygdala, which increases vigilance toward threats and improves your ability to detect and avoid danger. In other words, stress makes you fight, flee, or freeze—not think, "What would a prudent reaction be at this moment? Let’s consider the options". This makes good evolutionary sense: Half a million years ago, taking time to manage your emotions would have made you a tiger’s lunch.

But in the modern world, stress and anxiety are usually chronic, not episodic. Odds are, you no longer need your amygdala to help you outrun the tiger without asking your conscious brain’s permission. Instead, you use it to handle the nonlethal problems that pester you all day long. Even if you don’t have tigers to outrun, you can’t relax in your cave, because the emails are piling up.

Let me reiterate: "Half a million years ago, taking time to manage your emotions would have made you a tiger’s lunch".

This is the kind of cute, but bizarrely myopic statement one hears to justify the idea that stress is outmoded or badly calibrated. Another favourite is the idea that stress evolved to help us run from "lions on the savannah". Here's an article, from Psychology Today no less, that assumes the idea is so common the author can throw it out in the first couple of lines of an article with no particular explanation of why this would be a legitimate or helpful thing to say. The author goes on to use the motif with such illuminating comments as:

We can deal with our flu after we escape the lion

and

First, we run from the lion, only then do we worry about digestion

This ancient world, so thoroughly populated with lions and tigers intent on haphazardly chasing us during our few moments of post-prandial inner reflection, makes one wonder how anyone survived at all. Perhaps the lions never intended to catch us. They top out at a running speed of close to 80 kilometres an hour (~50 miles), so it seems unlikely that they'd miss. Maybe we were merely their post-prandial exercise.

Or perhaps that made up world doesn't make any kind of sense, particularly during a discussion of the extraordinarily complex human stress response.

¶Evolutionary stories are only so helpful

Evolutionary stories are a wicked temptress. So convincing in their power, and yet so flexible as to be regularly abused.

You can tell any number of evolutionary stories provided you're creative enough, because no one can go back in time to prove which is right. Like this one, telling us we are evolutionarily designed to be jealous and monopolising of our romantic partners or this one telling us the exact opposite---we are evolutionarily polyamorous at the core. And so these stories proliferate, and take on their own life.

Of course, what is more likely, is that many evolutionary stories are true at once. We simply choose the one most convenient, and then through its own process of evolution, the story gets shaped into its most hyperbolic form.

For stress, this has been a disaster.

The alluring evolutionary spectre of roving lions and tigers was, if not invented by, popularised by biologist Robert M. Sapolsky in his early '90s book Why Zebra's Don't Get Ulcers.

In this book, Sapolsky tells us that in the natural world, stress is usually an episodic thing---occurring every now and then, for short periods of time. Social primates, like baboons and (he speculates) humans, are more likely to create ongoing, chronic, sources of stress because they must deal with the ongoing interplay of social dynamics in their communities. Particularly clever primates, like humans, have the capacity to replay stressors, or anticipate them which, he also suspects lead to chronic, and not episodic stress.

What is missing from the usual distillation of Sapolsky's notes, is that his idea of chronic stressors are a little more substantial than bloody email notifications.

In baboons, being on the lower end of the dominance hierarchy counts, for him, as a chronic stressor---being in constant fear of violence from above. Similarly, in humans, the chronic stressors of our ancestral past probably weren't so different from the ones many face today, like the effects of child abuse, or chronic poverty.

Like many evolutionary narratives, Sapolsky's is attractive, and it has unfortunately taken on its own life, becoming something it was never meant to be.

Let me be the first to tell you that in the ancient world we probably had plenty of time to manage our emotions, entirely unmolested by errant tigers.

Let me also be the first to tell you that, then as now, the human stress response is one of the most valuable evolutionary technologies we have.

¶Stress is beautiful

The human stress response is an amazing piece of biology. Fundamentally, it is about keeping the body in balance---trying to maintain homeostasis. And typically, our stress responses are healthy and extremely useful. As usual, our unconscous processes are rarely the bad guy they've been made out to be.

By releasing certain stress hormones into the brain and body, the stress response will carefully calibrate our attention, increasing our level of physical arousal by recruiting various physiological and cognitive processes to meet some perceived challenge or threat.

Importantly, this stress response is the reason that we're any good at anything at all. Let me introduce you to the Yerkes-Dodson Law.

Any task that we might decide to do represents some kind of challenge. A task must be a challenge, because if it weren't, there would be no need to do the task at all. Something about the world is one way, and we must figure out how to make it another way. Hoc opus, hic labor est. Therein lies the task and the challenge that it represents.

Our physical arousal is the energising force that helps us achieve the effort required of us. In the early 1900s, Robert Yerkes and John Dodson discovered levels of arousal are closely matched to performance, and there is an optimal level of arousal to achieve optimal performance in a given task.

This is best illustrated in the graph drawn by Donald Hebb, of Hebbian learning fame, almost fifty years later:

As arousal increases, so does performance. To a point. Eventually, as arousal continues to increase, performance starts to decrease. Wikipedia.

What our diagram shows is that as arousal increases, so does our performance in a given task. We need arousal to perform. This kind of anxiety motivates us to perform, and it recruits all those physical and mental resources so important to doing something well.

It is only when we become too stressed---more anxious than the situation requires---that stress becomes a bad thing. Higher levels of anxiety begins to reduce our performance until eventually we're doing as badly as if we weren't stressed at all.

Yerkes-Dodson, however, noted that different kinds of tasks demand different amounts of effort. This might seem obvious, but it has some non-intuitive implications. For example, with particularly simple tasks, as arousal increases, performance increases as normal. But, because these tasks are simple, even if we continue to increase our levels of anxiety, our performance remains stably optimal:

For simple tasks, continuing to increase arousal has no effect on performance. Our performance increases to optimal levels and then remains there no matter how stressed we are. Wikipedia.

If the task is simply 'remember that this thing is stressful', then of course it's not going to matter particularly if that thing is 'stressful' or 'super-stressful'. You'll probably remember it just fine either way. Similarly, if the task is to merely 'pay attention to the thing', the amount of stress it causes will be irrelevant after it has captured your attention. It's only when you need to do something more complex that more stress interferes with your ability to respond.

This is quite a different picture to the one implied by the classic ideas of the fight or flight response. Stress does not merely prepare us to fight or flight. We're being prepared to do something, but that something we are being prepared for is typically precisely the thing we wanted to do.

¶Stress depends on the stakes

Of course, the Yerkes-Dodson law doesn't quite grapple with the complexities of the human experience.

There is more to being stressed than simply performance. There are also more kinds of stress than simply the kinds of tasks we think of when we encounter the word 'tasks'.

Another way to think about challenges is to think in terms of levels of threat.

¶High stakes

The 'fight or flight' response, more accurately known as 'hyperarousal', is the kind of stress we experience when we're facing something we think is some kind of immediate, physical, and harmful threat to our survival. If we look at the list of physical reactions while in this state of hyperarousal, we see that this is not the kind of thing that would be useful for an exam. But it would be very useful to optimally move out of the way of an unexpected cyclist.

This, I would assume, is what people are thinking of when they invoke the ancient hordes of conveniently slow lions. But to confuse this kind of 'hyperarousal' with the stress we experience because of too many email notifications seems a little lazy.

¶Low stakes

Less extreme threats also activate the sympatheticoadrenal system, but to a level that is far less intense. We might think of this as a kind of 'excitability system'. It is a subsystem of the Sympathetic Nervous System---which is, and I stress this,¹ constantly active at some level to help achieve homeostasis. Its job is to carefully calibrate our physical arousal to meet the level of threat, both 'hyper' and... less hyper.

One very interesting illustration of how carefully our bodies calibrate themselves to different kinds of stress comes when we consider our bodies during sex.

¶A little tangent: stress and sex

The sympathetic nervous system is often contrasted with the parasympathetic nervous system. You will often hear that the sympathetic nervous system is responsible for 'fight or flight' and the parasympathetic nervous system is responsible for 'rest and digest'---that is, all the unconscious bodily activity that goes on to maintain our bodies at rest.

This is, of course, an awfully simplistic distinction. And in fact, many now consider an entirely different third division of the nervous system that's responsible for the 'digest' part.

But, let's take this at face value for the moment. Of course, now we know now that the sympathetic nervous system is not just responsible for 'fight or flight'. In fact, as implied by the parasympathetic's 'rest and digest', it's responsible for everything that isn't resting. Anything that requires a quick response, essentially.

But what's interesting is that our 'rest and digest' system is also very important in our sexual arousal.

This should be a little warning flag to anyone hoping to separate our 'stress' response from our 'rest' response. I'd be quite concerned about the satisfaction or skill of one's sexual partner if one was to characterise sexual activity as restful.

In fact, we know that sexual arousal is so similar to the kind of physical arousal that comes from a fear-based stress response that we can easily confuse fear for attraction to someone. The famous study is that of the love bridge. Young men who are asked to rate a woman's attractiveness after speaking with her while crossing a rickety old bridge will rate much higher than those rating her attractiveness on a more stable bridge.² The physical arousal from the threat of the bridge was confused for sexual arousal from the woman standing in the middle of it.³

The sympathetic nervous system gives us the energetic drive to make love, and the parasympathetic nervous system prepares our equipment for the job---the kinds of unconscious preparations we get so upset about when they don't work properly, like the oh-so-important swelling of erectile tissue, lubricration, and moving the seed from the start of the journey to the end.

It should be no surprise, then, to find that optimal performance is reached when we are suitably stressed. Suitably energised to make love, but not so energised that the stress inhibits the parasympathetic system in its crucial preparations. The Yerkes-Dodson Law in action.

But these are all immediate term threats. Threats of violence, threats of missing a deadline, and threats of poor performance in the bedroom.

Stress is also useful over the longer term.

¶Stress over the medium-term

In the medium term, stress helps us to manage lasting dangerous situations. Consider, for example, the plight of those in war torn regions of the world or the not entirely un-related migrants taking part in unprecedented levels of, often dangerous, migration. In these situations, we have a constant level of threat over an extended period of time.

Stress induces in us a state of hypervigilence. Often associated with post-traumatic stress disorder, hypervigilence is not always a maladaptive trait. In an environment where there is a constant threat to our wellbeing, particularly when the nature and intensity of the threat is unpredictable, being hypervigilent is a perfectly reasonable way of being prepared for such a thing. It's only when the threat is not out there but in here, as it is for those survivors free of their traumatic circumstances, but reliving it in their minds and bodies, that hypervigilence causes more harm than good.

Stress also reduces our risk-taking behaviour---discouraging exploration and reward-seeking.⁴ Once again, a sensible way to approach a long term situation where rewards are non-existent or not worth the risk taken to achieve them.

¶Stress over the long-term

In the long term, stress eventually encourages us to shut down. To conserve our resources in the face of extremely harsh or unrewarding environments. Prolonged activation of the hypothalamic pituitary axis, another stress-related pathway, is associated with a huge array of negative long term health outcomes. But these outcomes seem to constellate around the reduction of energy expenditure and the reduction of reward-seeking and exploration behaviour. We see mood disorders (which are thought to help us conserve resources and slow down), weight-gain, and an increasing sensitivity to stimuli.

All fairly sensible responses when confronted with an environment that has nothing to offer us, but the chance of a better future after the storm has passed.

¶(Eu)stress and the modern era

Obviously stress is helpful, and just as obviously it's only helpful when it's helpful. Stress makes us less relaxed. It stops us sleeping. It focuses our attention at the expense of a wider perspective. It makes us uninterested in the usual kinds of rewards. It stops us from playing and exploring.

These are all very useful characteristics when we have a problem to solve or a challenge to overcome.

These are all very unhelpful when there is no such challenge.

More to the point, over time, these features of stress can reinforce themselves. If we aren't interested in reward, we might not perceive the points of light in the darkness. If we aren't motivated to explore, we might not find a way out. If we can't sleep and relax, we might eventually exhaust ourselves. And if we're hypervigilant to threat... well:

If we only look for the darkness, that is all we will see.

Uncle Iroh

This is the vicious cycle of chronic stress. And once again, the hypothetical hordes of lions loom large over the horizon. Perhaps our modern life is inducing more people to be more chronically stressed, more often.

There is a great deal of focus on the idea that our modern conveniences are contributing to unseasonable stress responses. If we return to the quote we started with:

But in the modern world, stress and anxiety are usually chronic, not episodic. Odds are, you no longer need your amygdala to help you outrun the tiger without asking your conscious brain’s permission. Instead, you use it to handle the nonlethal problems that pester you all day long. Even if you don’t have tigers to outrun, you can’t relax in your cave, because the emails are piling up.

But I would contend that this is an absurd characterisation of modern life. There is no world in which an abundance of email notifications are the equivalent of a tiger pursuit. Not only that, but the amygdala doesn't even work that way.

This is the sound of unthoughtful people making unthoughtful comments about the nature of stress. The sound of people who:

go ringing on in a long harangue, like brazen pots, which when they are struck continue to sound unless some one puts his hand upon them

Protagoras

So let us put our hand upon them. Let me introduce you to the notion of eustress. Eustress is the stress that happens on the left hand side of the Yerkes-Dodson curve:

Eustress is when arousal does not overwhelm performance. When it does, it causes distress. Wikipedia.

Eustress is the kind of stress that lies below or meets the challenge. The energising force that motivates us to succeed, but not to withdraw. Distress is what happens when our arousal exceeds the challenge. When the perception of the threat makes us too stressed to address it adaptively. Indeed, eustress is something quite overlapping with the idea of a flow state.

We might put it a different way and say that eustress arises when we face a challenge and distress is what arises from a threat. When we know we can meet the task, we are challenged. When we are afraid that we will fail, or too afraid to know how to respond, we are threatened.

Of course, every challenge contains a threat of failure or else, as I said, it wouldn't be a challenge in the first place. As such, these kinds of semantic distinctions are, perhaps, not that helpful. But importantly, this concept of eustress highlights the cognitive aspect of stress. Our perception of a stressor, whether it is distressing or eustressing, comes down to our perception of whether the challenge we face lies within our capacity to address it.

All emotions are simply motivations to act. A state of action-readiness to respond to the environment. Stress is one way to characterise a slew of motivating emotions.

But emotions are the product of the mind. We pass some visceral felt experience of goodness and badness to our psyche, which turns it into something sharper and more defined. But our brains have such an enormous selection of emotions, how is it that we choose the ones we do?

The answer lies in that attributions we make. Is the event our fault, or someone else's? Does it happen all the time, or only this time? Can we control it, or not? And so on.

Our expectations about the world determine the kinds of emotions we'll feel. And in the modern era, this is exceptionally true of many of the stressors that we face.

Email notifications are not stressful in the way a tiger is stressful. The comparison makes no sense. A tiger will eat the shit out of you. Unless you are enthusiastically suicidal, this is uncontroversially a bad thing. In contrast, a little red badge with a number inside has no particular valance at all, except that which you imbue it.

Modern stressors are often not physical predators, but psychic predators. Concerns we have chosen to stress about, as opposed to agentically prepare ourselves for. And while many of these concerns are not always perfectly in our control, many more are.

And thus, the answer to the modern email tiger is not the same as to the ancient hordes on the imaginary savannah. The answer is to learn how to appraise these stressors in a way that transforms them. From distress to eustress. Or perhaps to something that creates no stress at all. This happy task, is fortunately something that is well within our grasp.

And please, no more talk of ancient big cat plagues.