It creeps up on you as soon as the alarm clock rings. Fingers reflexively unlock your phone. Emails bound in with a jolly ping: things you should have done last week; pointless meeting requests; bills to pay.
Over a hurried breakfast you scan the headlines: wall-to-wall misery. On the train you turn to social media for relief. Gillian is funnier than you. Alex got promoted again. Laura’s sunning herself in Thailand. You’re here, packed in, surrounded but alone, rattling your way towards another overstretched day.
Stress: we know what it feels like, we can smell it on others, we complain about it most days. And we’re living through an epidemic of it. The government’s Health and Safety Executive estimates that stress cost the economy nearly ten million working days last year. Some 43 per cent of all sick days were attributed to stress. In the US, a large survey conducted by the National Public Radio network in 2014 showed that nearly one in two people reported a major stress event at some point in the previous 12 months. The year before that, American doctors wrote 76 million unique prescriptions for the anti-anxiety drugs Xanax and Ativan. With the media running stories about stress-induced heart disease, strokes, obesity, depression, ulcers and cancer, it’s hard not to conclude that stress kills.
But consider this: just a century ago, nobody got stressed. They suffered with their nerves, got a touch of the vapours; they worried; but they were never stressed. In fact, our current view of stress – what it is, what it feels like, and when it is harmful – evolved surprisingly recently. And research shows that the way we think about stress has a profound influence on how it affects us.
Prolonged, uncontrollable stress – particularly if suffered in childhood – can be profoundly corrosive and debilitating. But what of the familiar stresses of day-to-day life? Are they actually damaging you? Might the belief that stress is harmful be self-fulfilling? And what would a stress-free life look like? Instead of turning in on ourselves and doing battle with our personal stress demons, might we be able to put their diabolic energy to good use?
If we pause for a moment from our daily hustle we would see that many of us are incurably hooked on stress. We thrive on it, getting a kick out of surviving the high-stakes presentation, meeting the deadline and overcoming our fears and prejudices. Watching a thriller, we are on the edge of our seat, pulses racing. Sports, on the field or on television, can propel us into “fight or flight” mode. Humanity’s fascination with gambling hinges on stress.
If the most skilled physiologists in the world could peer beneath the skin of a thrill-seeker on a roller coaster and an out-of-his-depth job interview candidate, they would struggle to tell them apart. Deep in the brain, they would see a structure called the hypothalamus fired up. With each lurch of the ride or disarming question asked, the hypothalamus signals to the adrenal glands, which sit atop each kidney. The adrenals then squirt a shot of adrenalin into the bloodstream. In the background, the hypothalamus prods the pituitary gland, which passes a different message on to the adrenal gland. This increases production of cortisol, the textbook “stress hormone”. Flipping these biological switches triggers the familiar bodily symptoms of stress: a pounding heart, raised blood pressure, dilated pupils, arrested digestion and a damped-down immune system. In both cases, the biological stress response would look very similar.
Even if we could eliminate stress entirely, or smother it with pharmaceuticals, we wouldn’t want to. To muzzle the stress response is to silence the good as well as the bad. At best, stress can motivate us to achieve more and fix the sources of our stress. Boredom is stressful in its own way: observe a caged lion, or an understimulated teenager. In fact, as the animal psychologist Françoise Wemelsfelder told New Scientist recently, boredom may exist to spur us back into activity. This half-forgotten idea, that some degree of stress can inspire and elevate, is common sense. It also has deep roots in the earliest scientific study of stress and stress responses.
At the beginning of the 20th century, two American psychologists, Robert Yerkes and John Dodson, wanted to know how stressing out lab mice affected their learning. They set the rodents navigational challenges and punished wrong turns by administering small electric shocks to the feet. In their terminology, larger electric currents caused greater “arousal”.
They spotted some consistent trends. When they gave mice an easy task (choosing between a black or a white tunnel) the relationship between the strength of the shock and the speed of learning was simple. The greater the stressor, the quicker the mice learned to pick the right tunnel.
When the challenge was subtler (differentiating between grey tunnels), the response was less straightforward. Weak shocks provided little impetus to learn, but as the zaps got stronger, the mice gradually upped their game. They focused on the task and remembered the consequences of wrong choices. Yet, at a certain point, the high stress levels that helped with the easy task became counterproductive. Overwhelmed, the mice skittered around at random, trying in vain to escape.
On a graph, the relationship between stress and performance on onerous tasks traces an inverted U shape. Some degree of stress helps, but there is a clear tipping point, beyond which stress becomes paralysing. The findings became known as the Yerkes-Dodson law.
This was all very well for mice, but could it be applied to human beings? According to the Canadian-Austrian endocrinologist Hans Selye, the “father of stress”, it could. Selye was the first person to describe the key glands, hormones and nerves of the biological stress response during the 1930s and 1940s, and also one of the first to apply the word “stress” to human biology.
For Selye, “stress” described an all-purpose response the body had to any demand placed upon it. When stress is on the upswing of Yerkes and Dodson’s inverted-U performance curve, Selye calls it “eustress”. This is where good teachers and managers should push their charges: to the sweet spot that separates predictable tedium from chaotic overload. Where stress gets more persistent, unmanageable and damaging, Selye calls it “distress”. Eustress and distress have identical biological bases; they are simply found at different points on the same curve.
Despite this knowledge, stress has a terrible public image today, often synonymous with distress. While some wear their stress as a badge of honour (“I’m important enough to be stressed”), deep down even the most gung-ho City workers probably stress about their stress. And in painting stress as a beast, we grant it more destructive power.
When did we come to view stress as the universal enemy? Mark Petticrew, Professor of Public Health Evaluation at the London School of Hygiene and Tropical Medicine, has sifted through a huge archive of historical tobacco industry documents. In a 2011 paper, he revealed that a large proportion of stress research during the second half of the 20th century was funded, steered and manipulated by this most unexpected of benefactors. Indeed, from the late 1950s, Hans Selye received hundreds of thousands of tobacco-stained dollars. He also allowed industry lawyers to vet his research and appeared in several pro-tobacco propaganda films.
“They put a massive, massive amount of money into it,” Petticrew told me.
Why were tobacco manufacturers so interested in stress? First, cigarettes were marketed as a stress reliever. “To anxiety . . . I bring relief,” reads a 1930s advertisement for Lucky Strike. So if research could help them pin poor mental and physical health to stress, this sort of message would carry more weight. (Incidentally, the still widespread belief that smoking reduces anxiety appears to be wrong.)
Later, as evidence grew that smoking caused cancer and heart disease, the tobacco industry wanted to prove that stress was an equally significant risk factor. They used the authority of Selye and several other leading researchers as a smokescreen. “Doubt is our product,” read a top industry executive’s 1969 memo. And so doubt they sowed, arguing repeatedly that stress was a major cause of disease. Those seeking to control tobacco were wrong, they claimed.
It worked: the industry convinced the general public of the evils of stress and diverted public health research for at least a decade. With tobacco regulation and compensation payouts postponed, the profits kept rolling in.
Should we doubt the veracity and neutrality of all the foundational research into stress as a disease? “I wouldn’t want to argue that stress doesn’t exist, or that it isn’t bad for your health and certainly your mental health,” Petticrew says. “But you can’t ignore this story.”
He goes on to describe concrete “findings” that industry-funded researchers got wrong. Prominent among these was a link between coronary disease and people displaying so-called Type A personality traits: competitiveness, ambition, anxiety. Such temperamentally “stressed” people were especially likely to suffer heart attacks and, not coincidentally, to smoke. Then the association faded away. “Aside from the scientific weaknesses, which are many, Type A is a cultural artefact to some extent constructed by the tobacco lobby,” Petticrew says. And yet, despite its fragile foundations, the Type A myth persists today.
The long shadow cast by decades of one-sided, propaganda-laced stress research has led many people to believe that stress is a direct cause of heart attacks. But the British Heart Foundation’s website states, “There is no evidence to suggest that stress causes coronary heart disease or heart attacks.” Nor does it cause stomach ulcers: usually it is a bacterium called Helicobacter pylori which does that.
The tobacco-funded researchers didn’t get it all wrong. Stress does have clear causal links to some diseases, particularly mental illnesses, including depression, anxiety disorders, schizophrenia and addictive behaviour. High stress levels appear to be a general risk factor for early death, among middle-aged men in particular. Moreover, we all know how unpleasant stress can be. From insomnia to binge eating and boozing, we respond to stress with all sorts of counterproductive and antisocial behaviours. And that is partly why the tone of messages we hear about stress matters so much. Human beings are inherently suggestible and particularly vulnerable to warning messages about our health, especially when those messages seem to be backed by science.
With mice in a cage, you can measure the tipping point – the precise current of the electric shock – where good stress becomes bad. But we don’t need the lurking menace of a lion in the long grass to activate our stress response. We can do it perfectly well for ourselves. All it takes is a negative thought, the memory of an insult, or a vague feeling of unease.
We can think our way into stress. And, as recent evidence shows, if we believe stress is going to hurt us, it is more likely to hurt us. This is one message emerging from the Whitehall II project, a long-term study of 10,000 UK government civil servants, set up in 1985 to study the social, economic and personal determinants of health and disease. A 2013 analysis of Whitehall II data concluded that people who believe stress adversely affects their health are more than twice as likely to suffer a heart attack, irrespective of their stress levels.
There is a flipside to this gloomy news. If our thoughts and beliefs can switch on a damaging stress response, can they also switch it off? Could the power of suggestion be a partial vaccination in the battle against the stress epidemic?
This is the contention of Alia Crum, a psychology professor at Stanford University and a flagbearer for the science of mindset manipulations. In 2007 she showed that if hotel chambermaids come to think of their work as exercise, they lose weight and their blood pressure falls, apparently without them working any harder. More recently, she described how UBS bankers who were shown videos about the life-enhancing effects of stress – how it can sharpen attention, boost cognition and force fresh perspectives – reported being more productive, focused and collaborative, and less afflicted by depression and anxiety.
The inescapable conclusion is this: the human mind is a powerful gatekeeper to the stress response. But we have to tread carefully here. UBS employees may have the freedom to choose a less stressful life, and find opportunity to reshape their stress mindsets. What about those whose stress is delivered early and compounded by a lifetime of disadvantage and adversity? Perhaps this is where the story of familiar, workaday stress and the grinding strain of social injustice come together. Stress gets under our skin only when we can’t see the end or spot the fix. So what, other than using Crum’s mindset interventions, can we do to restore the critical feeling of empowerment?
Emily Ansell, an assistant professor of psychiatry at Yale, says that reaching out a kindly hand to your fellow human beings can be surprisingly helpful. In a study published last year, Ansell and colleagues gave a group of 77 people a diary-like smartphone app. They asked the subjects to record all the stressful incidents they encountered, and any minor acts of kindness they performed, during a 14-day period. The data shows that gestures such as holding doors for strangers and helping elderly people across the road buffer the effects of stress and make you feel more optimistic.
Positive interactions deliver a reward at the neurological level. They restore a sense of control and show that meaningful relationships are possible. Moreover, helpers often get more psychological and health benefits than those on the receiving end of that help.
How do we encourage prosocial behaviour throughout society, particularly at the margins? According to Paul Piff, a social psychologist at the University of California, Irvine, lower-class people in America often “have less and give more”. They are more generous, charitable, trusting and helpful than their upper-class counterparts. It’s possible that this tendency to reach out and muck in is a direct response to a life of chronic stress. In response to Piff’s theory, Michael Poulin, a professor of psychology at the University of Buffalo, suggests: “We should perhaps really focus on encouraging prosocial behaviour among the well-off, potentially leading to benefits both for them – in terms of stress – and for the disadvantaged, who would presumably benefit from their generosity.”
This article is published simultaneously in the Long + Short, the free online magazine of ideas published by Nesta, the UK’s innovation foundation. thelongandshort.org