The relationship between stress and performance has been known for about a century in psychology. It’s called the Yerkes-Dodson Law. While the psychologists Yerkes and Dodson could not have known it 100 years ago, they were actually tracking the impacts of the HPA axis, the circuitry that secretes stress hormones when the amygdala gets triggered.
This is a different way of thinking about how the brain operates to help or hurt our performance – whether at work, in learning, in a sport, in any domain of ability. There are three main states depicted in the Yerkes-Dodson Law: disengagement, flow, and frazzle. Each of these has powerful impacts on a person’s ability to perform at their best: disengagement and frazzle torpedo our efforts, while flow lets them soar.
The impact of stress arousal on performance.
The relationship of stress to performance, captured in the Yerkes-Dodson Law, shows that boredom and disengagement trigger too little of the stress hormones secreted by the HPA axis – and performance lags. As we get more motivated and engaged, “good stress” brings us to the optimal zone, where we perform at our best. If the challenges get too great and we become overwhelmed, we go into the zone of burnout, where stress hormone levels get too high and hamper performance.
Workplaces the world over are rife with people stuck in disengagement: they’re bored with their jobs, uninspired and disinterested. They have little to no motivation to give their best, instead just doing well enough to keep the job. Studies of employee engagement find that in top-performing organizations, there are ten times more fully engaged workers than disengaged, while in average-performing outfits there are just two engaged employees for every disengaged one17. Engaged employees are more productive, give better attention to customers, and are more loyal to the organization.
As we move from boredom toward the optimal zone on the performance arc, the brain triggers increasing levels of stress hormones, and we enter the range of “good stress,” where our performance picks up. Challenges – like getting motivated to reach a goal, or being called on to exhibit your best skills, or a team’s race to meet a deadline – focus our attention and elicit our best efforts on the job at hand. Good stress gets us engaged, enthused and motivated, and mobilizes just enough of the stress hormones cortisol and adrenaline – along with beneficial brain chemicals like dopamine – to do the job effectively. Cortisol and adrenaline have both protective and harmful impacts, and good stress mobilizes their benefits.
But when demands become too great for us to handle, when the pressure overwhelms us – too much to do with too little time or support – we enter the zone of bad stress. Just beyond the optimal zone at the top or the performance arc there is a tipping point where the brain secretes too many stress hormones, and they start to interfere with our ability to work well, to learn, to innovate, to listen, and to plan effectively.
The costs of chronic stress go well beyond performance. In this zone what’s technically called “allostatic load” means the damaging effects of stress hormones predominate. Too-high levels of those hormones over too long a period throw neuroendocrine function off-kilter, and create imbalances in the immune and nervous systems – so we are more susceptible to illness, and have trouble thinking clearly. Our body clock becomes confused and we sleep poorly.
Long before I had heard of the HPA axis, back in my graduate school days, my doctoral dissertation documented this. I measured people’s physiology – monitoring their heart rate and sweat response – while they watched a film that had been made to inspire wood workers to use their safety devices. There are three accidents portrayed in this film, each accident is due to the woodworker’s failure to use a safety device. In the first accident you see Mack pushing a huge piece of plywood into a gigantic circle saw that has scarily spiky teeth -- and he hasn't put his safety device on. His thumb is heading straight for that saw. But Mack is talking to his pal, George, and doesn’t notice. As Mack’s thumb gets closer to the saw, apprehension builds, as I could see by the heart rate and sweat response of people watching that film. I knew exactly when the thumb hit the saw by watching people’s readouts go higher and higher, as their amygdala went into overdrive.
Once the accident is over, heart rates and sweat would lessen as people started to recover. But then the next accident gets set up, and because they haven't recovered all that much, their reactivity goes even higher during the second accident. By the third one, they literally went off the chart – in those days we used pen and paper, something like on a polygraph – and the needle would fly off the paper by the third accident.
That is the anatomy of a bad day. That escalating stress reaction is what happens inside on those days when you oversleep because your alarm didn't go off, so off the bat you’re going to be late for some important meeting. Then the kids don't cooperate or you have a tussle with your partner, so you leave home upset and grumpy. Then your car won't start, and it’s just one frustrating thing after another – and all this even before you get to work. Your stress hormones are pumping.
That scenario fits ongoing hassles, one of the classic causes of allostatic load, which, if it becomes a chronic fixture in our life, can make us more susceptible to disease. Scientists find that repeatedly having to face a range of different stressful events will do it. So will one chronic source of stress – like an abrasive co-worker – that we never adjust to. Another cause is when we keep ruminating about the things that upset us – for example, waking up in the middle of the night and obsessing about it – and so fail to turn down the volume on the stress response18.
Scientists who study HPA arousal find one of the most dependable ways to trigger cortisol and adrenaline is a simulation of a real-life job application. People who are out of work are told they can get coaching in how to apply for a job. They come in to a psych lab and have their physiology measured as they go through what they think is a practice job interview. Actually the person they're talking to is a confederate of the experimenter, who starts giving negative nonverbal feedback, like looks of disgust, as the applicant starts talking, and then goes on to give the poor applicant outright criticism. Understandably, this reliably activates that HPA axis. Managers and supervisors should be aware that this can be what happens to people if you focus in performance feedback solely on what they did wrong, rather than how they can improve and what they did well.
At the maximal output of stress hormone, you enter the state of being overwhelmed, which greatly impairs our cognitive abilities -- for example, performance in math and language can drop fifty percent. While frazzled you respond in a rigid and flexible way. You can't adapt to new situations. You can't concentrate – you're easily distracted.
Chronic overwhelm can harm the hippocampus, which is crucial for learning: this is where short-term memories, like what we’ve just heard or read, are converted to long-term memories, so we can recall them later. The hippocampus is extraordinarily rich in receptors for cortisol, so our capacity to learn is very vulnerable to stress. If we have constant stress in our lives, this flood of cortisol actually disconnects existing neural networks; we can have memory loss. This kind of extreme memory loss has been seen in clinical conditions, like post-traumatic stress disorder and extreme depression.
More recent research reveals how the biological effects of such bad stress endanger our health in many ways19. There's an increase in abdominal fat, and insulin resistance goes up. The body becomes more prone to diabetes, heart disease, and artery blockages. The effectiveness of the immune system plummets. Cortisol degrades the myelin sheath that coats nerve pathways, impairing the transmission of signals from one brain area to another. In short, the neural, cognitive and biological effects of extreme stress are even worse than had been thought.
Where we want to be on the Yerkes-Dodson arc is the zone of optimal performance, known as “flow” in the research of Mihaly Csikszentmihalyi at the University of Chicago. Flow represents a peak of self-regulation, the maximal harnessing of emotions in the service of performance or learning. In flow we channel positive emotions in an energized pursuit of the task at hand. Our focus is undistracted, and we feel a spontaneous joy, even rapture.
The flow concept emerged from research where people were asked to describe a time they outdid themselves and achieved their personal best. People described moments from a wide range of domains of expertise, from basketball and ballet to chess and brain surgery. And no matter the specifics, the underlying state they described was one and the same.
The chief characteristics of flow include rapt, unbreakable concentration; a nimble flexibility in responding to changing challenges; executing at the top of your skill level; and taking pleasure in what you’re doing – joy. That last hallmark strongly suggests that if brain scans were done of people while in flow we might expect to see notable left prefrontal activation; if brain chemistry were assayed, we would likely find higher levels of mood and performance enhancing compounds like dopamine.
This optimal performance zone has been called a state of neural harmony where the disparate areas of the brain are in synch, working together. This is also seen as a state of maximum cognitive efficiency20. Getting into flow lets you use whatever talent you may have at peak levels.
People who have mastered a domain of expertise and who operate at the top of their game typically have practiced a minimum of 10,000 hours – and are often world class in their performance21. Tellingly, when such experts are engaged in their skill, whatever it may be, their overall levels of brain arousal tend to become lower, suggesting that for them this particular activity has become relatively effortless, even at its peak.
An early brain study suggested that while people are in flow, only those brain areas relevant to the activity at hand are activated. This contrasts with the brain of a person who is bored; then you see randomly scattered neural activation, rather than a sharp delineation of activity in the areas relevant to the task. In the brain of a person who is stressed, you find lots of activity in the emotional circuitry which is irrelevant to the task at hand, and which suggests an anxious distractedness.
An organization will be top-performing to the extent to which its employees can contribute their best skills at full force. The more moments of flow – or even just staying in the zone of engagement and motivation – the better. There are several pathways to flow:
•Adjust demands to fit the person’s skills. If you manage people’s work, try to gauge their optimal level of challenge. If they're under-engaged, increase the challenge in ways that make their work more interesting – for instance by giving a stretch assignment. If they are overwhelmed, reduce the demand and give them more support (whether emotional or logistic)
•Practice the relevant expertise to raise skills to meet a higher level of demand
•Enhance concentration abilities so you can pay more attention, because attention itself is a pathway into the flow stage.
Finally, we need to notice when we – or others – have left the zone of positive stress and peak performance, so we can apply the apt remedy. There are several indicators to watch for. The most obvious is performance decline: you can't do the task as well, whatever the metric may be for measuring it. Another is wandering attention, loss of focus, or boredom. And there are more subtle clues that can show up before a noticeable performance decrement. For example, someone who seems “off” compared to how they normally do things, or who seems very rigid in how they respond rather than considering alternatives, or who is cranky and easily perturbed – any of which might signal that anxiety is impairing their cognitive efficiency.
The formula for eliciting flow includes a balance between the demands of the situation and a person’s skills – very often flow occurs when we are challenged to use our abilities to their utmost. But just where that optimal point will be varies widely from person to person. I was talking about flow and the performance arc with a military jet pilot. He told me that what would be a zone of extreme frazzle for most people is where jet pilots get into flow. But that’s because to qualify as a jet pilot, your reaction time has to be in the 99th percentile – an almost super-human quickness. He said, “We operate on adrenaline,” and that’s where the fun is for them.
A general strategy for enhancing the likelihood of flow is to regularly practice methods that enhance concentration and relax you physiologically. Treat these methods like you would your fitness routine – do them every day, or as many days as you can. For example, I like to meditate every morning, and I think it helps me stay in a positive, calm, and more focused frame of mind through most of the day. If you are in a high-stress job, you can benefit from regularly giving your brain and body the chance to recover and relax. Meditation is only one of many methods for getting relaxed; the key point is to find one you like and practice it regularly.
Anything that truly relaxes you helps. I don't mean you should go jogging while you're worrying about every little thing that's going wrong – that’s not relaxation. I mean playing with kids, or taking the dog for a walk, or a round of golf, or whatever is going to get you in to a relaxed state. The more you can break the cycle of the right prefrontal capture by the amygdala, the freer you'll be to activate the beneficial circuitry of the left prefrontal cortex.
If you do a regular practice like mindfulness, this greater activation of left hemisphere arousal seems to become more prominent over time – and the biggest change seems to be in the first months of practice. So far the strongest data point on this right-to-left prefrontal shift is the research that Davidson did with Jon Kabat-Zinn where they had people in a high-stress workplace practice mindfulness. They are currently repeating that study to be sure it replicates, and to understand better the conditions that facilitate the benefits of a practice like mindfulness. How often or how long do you need to practice to see neural or physical shifts? Do some kinds of people benefit more than others? These are the kind of questions we need more research to answer.
Another question, apart from the anti-stress benefits, is how can you enhance concentration abilities? Concentration is mental skill, and every skill can be enhanced by practice. But with the escalation in distractions we all face these days, this becomes a crucial issue in the workplace. The more we are distracted, the less effective we become.
Cognitive neuroscientists like Davidson are turning their attention to classical methods of meditation, which are, from the cognitive perspective, training exercises for a keener attentional focus. There are a multitude of meditation methods in the European and Asian spiritual traditions, and many can be seen, essentially, as ways of building concentration (quite apart from their spiritual function). The cardinal rule of all concentration enhancement techniques is to focus on A and whenever your mind wanders off to topic B or C, D, E, F, and you realize that it has wandered, bring it back to A again.
Every time you bring the wandering mind back to a concentrated state you're enhancing the muscle of concentration. It’s like being on a Nautilus machine and doing repetitions for a muscle, only you’re strengthening a muscle of the mind: attention.