Contents

About the Book

About the Author

Title Page

Dedication

Epigraph

Acknowledgements

Introduction

Chapter 1: The Impulse That Saved My Life

Chapter 2: Impulses and Your Zombie Brain

Chapter 3: Inside the Impulsive Brain

Chapter 4: The Teenage Brain – A Work in Progress

Chapter 5: Impulse and the Senses

Chapter 6: The Power of the Visual

Chapter 7: Impulses and the Risk-Taking Personality

Chapter 8: The Love Impulse – ‘It Only Takes a Moment’

Chapter 9: The Overeating Impulse – Digging Our Graves with Our Teeth

Chapter 10: The Buying Impulse – The How and Why of What We Buy

Chapter 11: The Imitation Impulse – ‘A Beautiful Place to Die’

Chapter 12: Deplete Us Not Into Temptation

Afterword: Free Will Is a Grand Illusion

Notes and References

Bibliography

Index

Copyright

Impulse

Why We Do What We Do Without Knowing Why We Do It

Dr David Lewis

‘Instinct leads, intelligence does but follow.’ William James, The Varieties of Religious Experience: A Study in Human Nature, 1902.

About the Book

When you make a decision or form an opinion, you think you know why. But you’re wrong.

The truth is that most of our mental activity actually happens below the level of conscious thought. In this groundbreaking book, Dr David Lewis, director of the cutting-edge research agency Mindlab International, explores this incredible phenomenon. Delving into the mysteries of the ‘zombie brain’ that each of us possesses, he demonstrates how unconscious neurological processes underpin every aspect of our lives, from whether or not we find someone sexually attractive to how we resist (or give in to) temptation. In the process he shows how finger length is a reliable predictor of risk-taking behaviour, how seeing the logos of fast food chains can make you more impatient, and how holding a warm drink makes you find strangers more likeable.

Above all, he reveals the practical applications of this emerging field of research, giving us insights into such diverse areas as child development, anti-social activities like rioting, successful dieting, and even the ways that supermarkets make us spend more. We may not be conscious of our impulses but it is clear that we can no longer afford to be ignorant of them.

About the Author

Dr David Lewis is founder and Director of Research at the independent research consultancy Mindlab International. Dubbed the ‘father of neuromarketing’ for his pioneering studies analysing brain activity for research and commercial purposes, he currently specialises in non-invasive techniques for measuring human responses under real-life conditions. He is the founding member of the Impulsivity Research Group (http://www.impulsive.me.uk/), which is dedicated to researching the psychology, neurology and genetics of impulsive behaviour.

Acknowledgements

Many people have assisted me in writing this book and I am especially grateful to those members of the Impulse Research Group for their support and invaluable contribution.

My special thanks to Dr John Storey for his medical insights and valuable comments on early drafts of the text. I would like to thank my colleagues at Mindlab International, Joe Hilling MSc, Director of Data Analysis and Duncan Smith, managing director for their assistance. Also my thanks to neuroscientist Charlie Rose for his work on the references and critique of the text. Steven Matthews has, as always, been diligent in reading and commenting on the text. I extend my warmest thanks to Dr Margaret Yufera-Leitch of the University of Calgary, one of the world’s foremost experts on obesity whose contribution to the chapter on impulsive eating was significant and important. I am most grateful to Coastguard station chief Don Ellis for his insights into the minds of suicides, knowledge gained by often dangerous experience in recovering the bodies of those who were successful and talking others to safety. My thanks also go to Dr Sean Kelly for his valuable assistance.

Finally, I am most grateful to Nigel Wilcockson and Sophie Lazar, my editors at Random House, for their invaluable and essential contributions to the shaping of the book.

Where necessary, names and personal details in the case histories cited have been changed for reasons of confidentiality and to protect privacy.

Copyright acknowledgements

I would like to thank Dr Hannah Faye Chua for permission to use two images from ‘How we See it: Culturally Different Eye Movement Patterns Over Visual Scenes’ from the article by Boland, Chua, and Nisbett (2005). In Rayner, K., Shen, D., Bai, X., Yan, G., (Eds.) Cognitive and Cultural Influences on Eye Movements. Tianjin, China: People’s Press/Psychology Press, pages 363–378.

Also I am most grateful to Dr Richard Russell, Assistant Professor of Psychology at Gettysburg College, for kindly allowing me to use two photographs from his excellent paper ‘A sex difference in facial contrast and its exaggeration by cosmetics’, which appeared in the 2009 issue of Perception.

Thanks to Meg Bury of the explOratorium in San Francisco for permission to use a photograph of the Ames Room which forms part of their permanent exhibition.

To Dr Russell Swerdlow, co-author of the 2003 Archives of Neurology paper: Right orbitofrontal tumor with pedophilia symptom and constructional apraxia sign, for his kindly assistance.

My thanks go to artist Terry Ayling for creating the line and tone illustrations and to Norman Clark for constructing a model of the Ames room used in my research.

The images here are reproduced by kind permission of: Figure 2: The Thinker, 1880-81 (bronze), Rodin, Auguste (1840-1917) / Burrell Collection, Glasgow, Scotland / © Culture and Sport Glasgow (Museums) / The Bridgeman Art Library. Figure 2: Discobolus, copy of a Greek original (plaster) (b/w photo), Myron, (fl.c.450 BC) (after) / Museo Nazionale Romano, Rome, Italy / Alinari / The Bridgeman Art Library. The images of female and male models here are reproduced courtesy of Bigstockphoto.com.

To S.M. with my love and gratitude.

Introduction

As I write these words, my head is watching me from across the room. Every so often the eyes – a colour match for my own – blink. From time to time the mouth silently opens and closes. Created from a life cast that involved pouring gloopy blue resin all over my head and shoulders, while I breathed through straws stuck up each nostril, it is a perfect replica.

Perfect, that is, save for one rather sobering difference. While I have aged, my second head, created more than a decade ago, remains – like some three-dimensional Dorian Gray in reverse – youthful. It still has a full head of hair – each one individually and painstakingly inserted by hand – while mine is fast receding. Its brow is smooth while mine is furrowed. An even more important difference is that you can lift the top of the head of my doppelgänger and remove the brain. Indeed I often tell people I originally had it made as an attention-grabbing lecture aid for teaching neuropsychology. This, at least, is the explanation I usually offer when asked why on earth I invested so much time and hard-earned cash in such a bizarre acquisition. In truth it is really a justification for what was an irrational and absurd impulse purchase. A purchase which I can only explain away, as is the case with most impulsive acts, by saying it seemed like a good idea at the time!

While the impulse that led me to have a second head created was one of my more expensive, it was by no means my most life-changing. Of these there have, so far, been three. Two altered the course of my life completely while the third, which I describe in Chapter 1, saved it.

My first life-transforming impulse occurred when I was 21 and browsing in a second-hand bookshop on London’s Charing Cross Road. Until that epiphany, my aim had been to qualify as a medical doctor. When I was ten my parents, knowing I had a great interest in biology, gave me a proper grown-up laboratory microscope. For the next eight years I spent much of my free time dissecting everything from road kill to sheep’s eyes and ox hearts to pig brains obtained from our friendly local butcher. To record my dissections I learned how to take photographs and soon expanded my photographic interests to record local news events, selling the pictures to local newspapers to help finance my science studies. In time I was accepted into medical school and started working to achieve my lifetime’s ambition. Eighteen months into my medical studies, wandering aimlessly around that second-hand bookshop, I chanced upon a copy of People I Have Shot by James Jarché, one of Fleet Street’s earliest press photographers. Jarché’s life story fascinated me and rekindled my interest in photography. I spent half the night reading it and, the following morning, hunched over a formaldehyde-soaked limb in the dissecting room, decided on an impulse to give up medicine and study photography instead.

The next afternoon I applied for and was given a place on a three-year photography course at the then Regent Street Polytechnic School of Photography, now part of the University of Westminster. When the course finished I moved first to Paris and then back to London to work as a photojournalist for magazines such as Paris Match, Stern, Oggi and Life. It was a career I pursued with interest and enjoyment for some years until changing course for the second time. Once again on an impulse that occurred at precisely 4.30 on the afternoon of 23 December 1976. A few weeks earlier, a meeting with a clinical psychologist, whose work was the subject of a magazine assignment, opened my eyes to the fascinating and important discipline of psychology. While drinking a cup of tea in the picture agency’s Fleet Street offices I took a spur-of-the-moment decision to return to university and read psychology.

That impulse resulted in a complete change of direction in my life and a career that still fascinates me more than three decades later. It has also led to my long-standing professional interest in the psychology of ‘impulsivity’, in trying to make sense of those spur-of-the-moment decisions that often change our lives. To understand our behaviour in all its many and varied facets, it is essential to understand impulses, since these (as I shall explain in Chapter 2) comprise the vast majority of our actions. We all like to regard ourselves as rational human beings. To believe we act only after careful reflection and thoughtful deliberation. The fact is, however, that our actions are mindless far more often than they are mindful: the product not of logic and reason but of habits driven by emotions.

Whenever we are motivated by joy or anger, jealousy or envy, love or lust, compassion or avarice, hatred or a desire for revenge we think, speak and act impulsively. We blurt out indiscretions, rush to judgements, make snap decisions, jump to conclusions, take leaps of faith and trust gut feelings far more than rational analysis. It doesn’t matter that we know better! It doesn’t matter that we’re aware of the remorse we will later feel for our impulsive deeds. At some point self-control simply deserts us and we fall in love with the wrong person, impulsively buy things we don’t really need, take reckless financial risks, agree to a second helping of that delicious but waist-expanding chocolate cake, allow ‘a couple of drinks’ to turn into a steady flow of alcohol until closing time, jeopardise our health through overindulgence or succumb to peer-group pressure and participate in risky pranks. Impulses lie at the root of most personal and social problems ranging from obesity, alcohol and drug abuse, overspending, unwanted pregnancies, smoking, emotional problems, dysfunctional relationships, and school underachievement to a failure in achieving cherished life goals.

What is an impulse?

In some branches of science ‘impulse’ has an unambiguous meaning. To the physicist it is ‘an indefinitely large force that acts for a very short time that brings about a change of momentum’. As, for example, when we hit a nail with a hammer. To the neurologist it is ‘a wave of physical and chemical excitation along a nerve fibre in response to a stimulus’. Surprisingly, after almost a century of study, psychologists have still reached no clear consensus as to precisely what they mean by an impulse or why some people are so much more impulsive than others. One of the earliest attempts at a definition was made in 1890 by the pioneering American psychologist William James. ‘Impulses,’ he wrote, ‘[are] ephemeral thoughts usually tied to forceful urges.’ Many of the definitions offered by later psychologists were equally woolly and, on occasions, mutually contradictory.¹

In the following chapter I shall be providing my own definition of an impulse when I explore two distinct ways of thinking that operate within the single brain. For the moment let’s just note that all the above definitions, whether from physics, biology, psychology or ordinary speech, express a common idea: that of getting things moving. The word itself comes from the Latin impulsus, which is related to impellere ‘to move’, and many impulses are indeed life-changing events. Small wonder, then, that they have fascinated philosophers, theologians and thinkers since the dawn of civilisation.

The impulse in history

The Greek physician Hippocrates offered one of the first explanations for impulsive behaviour in the fifth century BCE. He based his theory on the belief that a man’s personality depends on the balance between the four bodily fluids of black and yellow bile, phlegm and blood. A melancholy man was thought to suffer from an excess of black bile and a phlegmatic individual from too much phlegm. Impulsivity, Hippocrates believed, was due to excessive yellow bile producing a personality whose impulses were caused by anger – what he termed kakia or emotional evil. Too much blood in the mix, by contrast, resulted in a sanguine personality whose impulses were caused by aporia, which roughly translates as ‘perplexity’.

For Christians, and the other Abrahamic religions of Islam and Judaism, impulses presented a challenge that the faithful argued over for centuries. Since they believed God to be perfect, it followed that he would not create anything so imperfect as to exhibit impulsive behaviours. Yet humans often acted in ways that were manifestly impulsive. Their solution to this apparent contradiction was to invent the devil and blame all impulses on him.²

The 15th and 16th centuries were Satan’s golden age. It was a period during which plunging temperatures during Europe’s mini-ice age led to crop failures which, combined with rising populations, left many starving. Between 1683 and 1684, during what became known as the Great Frost, the Thames froze over so completely for two months that oxen were roasted on its centre. Ice nearly a foot thick covered the tidal waters and unbroken ice extending miles off the coasts of the England, France and the Low Countries blocked many harbours and caused severe problems for shipping. For nations afflicted by disease, crime and endless wars these meteorological disasters were seen as omens and portents. Among the faithful, there was bewilderment that a merciful God could cause such pain and suffering. Around 1486, Jacobus Sprenger and Henricus Institoris published their infamous Malleus Maleficarum, better known as The Hammer of the Witches. Their avowed purpose was to expose what, the authors claimed, were vast networks of witches and sorcerers dedicated to serving Satan.³ It was a time of witch-hunter generals, witch trials, witch burnings and witch hangings. An age in which mass hysteria seized people’s minds and fear of damnation destroyed their reason. A period when every type of impulse was explained by satanic influences.⁴ Principia Theologica, an anonymous 16th-century English catechism written for the growing literate middle classes, warns readers that the devil works by implanting ‘base, common thoughts of an impulsive and irresistible nature’ in their minds. In Germany, Martin Luther exhorted the faithful to ‘avoid the impulse to harlotry’, noting that ‘drunkenness begins as an impulse’ and warning congregations against entertaining impulses, lest they ‘conquer the will’. For Luther the devil was a very real and ever-present companion. A sufferer from chronic bowel pains, the theologian firmly believed that Satan had taken up residence in his lower intestine!

From around the start of the 18th century, however, Lucifer’s hold over the public imagination gradually declined and the witch trials gradually faded into history. ‘Satanic influence was always a convenient answer,’ comment William McCown and Philip DeSimone, ‘but one that gradually lost some appeal.’⁵ So long as impulsivity had been construed exclusively in spiritual terms, no progress could be made in understanding its basic causes. Indeed, the word ‘impulse’ does not appear on any documents until the middle of the 16th century, when it was used to describe ‘bad’ thoughts that arose for natural rather than devilish reasons. By the 17th century, some writers and thinkers were using the word to describe dysfunctional behaviour. Others, such as the 18th-century French writer and philosopher Jean-Jacques Rousseau, regarded it as one of the prime ‘virtues of natural man’: an individual who acted according to instinct and impulse rather than reason.

It was another Frenchman, the philosopher and physician Theopholi Bonet⁶ , who in 1684 made the first serious attempt to describe impulsivity in scientific terms. He distinguished between impulsive thoughts, obsessive thoughts, impulsive character, and the erratic and unstable moods found in manic-depressive illness. While asserting that impulses arose from mankind’s ‘base’ nature Bonet was careful to draw a distinction between individuals capable of controlling their impulsive thoughts and other ‘wretches’ who ‘by weakness of mind dwell on such (thoughts) without interruption’. These ‘wretches’, among whom Bonet numbered habitual criminals, drunkards and ‘all manners of men who practice moral rights and appear to profit not from instruction’, were, he contended, doomed to perpetual moral quandaries since they ‘know what to do, yet fail to do so’.

The third notable Frenchman to involve himself in this debate is now recognised as one of the greatest medical reformers of his age. Dr Philippe Pinel⁷ was a French physician who, during the late 18th century, laid the foundations for a more humane approach to the treatment and custody of psychiatric patients. As head of Paris’s sprawling Salpêtrière mental hospital – more of a small town than an asylum with some 7,000 patients – he caused a sensation by ordering the wardens to unchain female patients. He also insisted they be treated with kindness and tolerance rather than confinement and brutality. Pinel – in common with most ‘moral commentators’ and physicians of his day – struggled to resolve the conflict between notions of an individual’s personal responsibility for his or her actions, a function of their supposed ‘free will’, and the inescapable fact, which he observed daily, that many patients were incapable of ‘understanding’ the consequences of their actions. Moving around the crowded, chaotic wards he witnessed the distressing spectacle of patients, whose reason seemed unaffected by their madness, engaged in impulsive acts of self-harm. Even more curious, in his eyes, was the fact that those suffering from what he called la folie raisonnante appeared completely unable to learn from the often painful consequences of these behaviours. Such patients were, he concluded, suffering from manie sans délire, that is ‘insanity without confusion of mind’.

By the end of the 19th century a majority of medical practitioners, including most psychiatrists, had come round to his point of view. The consensus was that those suffering from ‘moral insanity’ were afflicted by overpowering ‘impulses’ that compelled them to act in ways which they themselves would view as morally evil were they capable of doing so. In 1900, an American named Walter Dill Scott⁸ , who had studied under Wilhelm Wundt – founding father of experimental psychology – wrote a lengthy dissertation on the psychology of impulses. In this he sought to develop a scientific definition of the concept that avoided any of the theological and moral implications surrounding it. He proposed that the newly established discipline of psychology could make a useful contribution to separating scientific fact from religious moralising.

Two years later, in one of the first psychiatric textbooks ever published, the German psychiatrist Eduard Hirt⁹ resurrected the ancient Hippocratic notion of the four humours – yellow bile, black bile, blood and phlegm. He suggested that all psychiatric conditions could be explained by reference to these bodily fluids. The personalities of patients with an overly sanguine temperament were, he considered, characterised by superficial excitability, enthusiasm and unreliability. Their principal problem, he believed, was a ‘lack of impulse control’. Those with excessive yellow bile displayed a ‘choleric temperament’ and were angry, vociferous individuals, equally incapable of controlling their impulses. A personality formed from a combination of choleric and sanguine humours displayed excessive impulsivity, a cavalier disregard for other people and bouts of explosive anger so intense on occasions as to have them regarded as ‘morally insane’. From being a spiritual manifestation of the devil’s power over man, the impulse had been transformed into a subject for psychological investigation and explanation.

My purpose in writing this book is to explain what psychology and neuroscience have discovered about why we do things on the spur of the moment, usually without knowing why! I will be describing the latest research findings and showing how our baser impulses are often deliberately manipulated for commercial and political purposes. I will explore the two types of thinking that go on simultaneously in the brain, the one slow and reflective and the other fast but prone to error. The development of the brain during the first two decades of life will be examined in order to understand why teenagers behave in a more impulsive and reckless way than adults. The important role played in decision-making by heuristics, those ‘rule of thumb’ mental strategies that are responsible for many impulsive misjudgements, are described together with the role played by personality in risk taking. The role of the senses in triggering impulses and the nature and limitations of self-control will be investigated.

In the second part of the book, I consider in detail four key aspects of life where impulses play a major role: these are falling in love, overeating, buying things on an impulse and the impulse that leads to the destruction of oneself or others. By understanding the strengths and weaknesses of impulses, by learning to identify those occasions when we should depend on them and the times when it would be better not to do so, we may enjoy a richer and more rewarding life.

CHAPTER 1

The Impulse That Saved My Life

‘Desires and impulses are as much a part of a perfect human being, as beliefs and restraints: and strong impulses are only perilous when not properly balanced.’ John Stuart Mill, On Liberty

ON 4 DECEMBER 1971, while working as a journalist in Belfast, I went to the cinema on an impulse. That impulse saved my life.

I had first visited Northern Ireland in September 1969, a few weeks after an attempted march by the Protestant Apprentice Boys through the Catholic Bogside area of Derry had led to three days of rioting. Three days later, on 14 August, with civil unrest and sectarian violence on the increase, the British government under Harold Wilson sent in troops for what they claimed would be a ‘limited operation’. It was the start of 20 years of conflict, bombings, murder and destruction that spread to the UK mainland and came to be known, euphemistically, as ‘the Troubles’. Initially welcomed by the Catholic community as a safeguard against Protestant violence, the soldiers soon came to be viewed as a hated army of occupation. By the early seventies, and especially after internment¹ was introduced in 1975, ‘the Troubles’ had developed into a bitter civil war, one fought as much between the Provisional IRA – the ‘Provos’ – and British troops as between the two religious communities. The mood of the Catholic community was summed up in a best-selling record of the time, ‘The Men Behind the Wire’, written and composed by Paddy McGuigan of the Barleycorn folk group.² While Protestant groups, such as the Ulster Volunteer Force (UVF), Tara, the Shankill Defence Association, the Shankill Butchers and the Ulster Protestant Volunteers, occasionally attacked British soldiers, their violence was mainly directed against Catholics.

By the time I returned to Belfast for my sixth visit, in late November 1971, killings and bombings had become almost a daily occurrence. In the first two weeks of December alone, 70 bombs exploded, 30 people were killed and scores more were injured. During earlier visits I’d come close to a severe beating – or worse – on a number of occasions, especially when taking photographs around the Falls Road.³ On this visit I came within minutes of falling victim to a terrorist’s bomb myself.

An appointment with the McGurks

Among the many friends I had made, on both sides of the sectarian divide, was Dr Jim Ryan. A Catholic GP, Jim had devoted his life to caring for the poor in slums around the Catholic Falls and the Protestant Shankill Roads, irrespective of their religion. At lunchtime on that bright but chilly December day, I met up for a drink with Jim in a bar called Kelly’s Cellars, the city’s oldest licensed premises.⁴ I told him that my latest assignment was to write about the effects of the violence on Belfast’s young people and asked whether he knew of any families with teenagers whom I could interview. Jim immediately suggested I talked with the McGurks.

Patrick and Philomena McGurk ran a public house called Tramore, known to locals as McGurk’s, which stood on the corner of North Queen Street and Great Georges Street. Although this was in a staunchly Catholic and Irish nationalist area of the city, Patrick and Philomena were well known for their lack of religious bigotry. They also had a bright, attractive and eloquent 14-year-old daughter named Maria. I gratefully accepted Jim’s suggestion and he arranged for me to meet mother and daughter at around 8.30 that evening.

I left my hotel shortly after seven to have a meal before going on to my meeting. It was a chilly night and the darkened streets of the city looked especially depressing and foreboding. On the spur of the moment I decided to go to the cinema. The film ended just before nine. I found a taxi easily enough and told the driver to take me to Great Georges Street. We never arrived at our destination.

Approaching the junction with North Queen Street it became clear a major terrorist incident had just taken place. The chilly night air was filled with dense smoke. I could smell the acrid fumes of explosive and burning timbers. The street was filled with fire engines, ambulances, police cars and army trucks. Eerily lit in the harsh white glare of emergency lamps and the occasional flash of a press photographer’s camera, soldiers and civilians scrambled and crawled over the avalanche of rubble, digging and burrowing desperately amongst charred timbers and fragmented brickwork. Of McGurk’s scarcely anything recognisable remained. A solitary, soot-blackened wall. A lone metal arch standing out amidst shattered timbers and twisted steel. The explosion had flattened the old building like a giant’s foot crushing a child’s toy.

At almost the exact moment I left the cinema, a bomb disguised as a brown-paper parcel had exploded in the entrance to the crowded bar. Seventeen people had been killed. Among them Philomena and her daughter. Maria had been doing her homework in the pub’s first-floor living room when the bomb exploded. She was killed instantly. If I had been with them, I too would almost certainly have died.⁵

I will discuss the possible reasons for that life-saving impulse in a moment. But let’s first look at three other examples of people who acted on an impulse and survived almost certain death as a result.

The man who was never late

Fifty-four-year-old Fred Eichler, Chief Financial Officer with the New York brokerage firm Axcelera, prided himself on always being punctual. That bright, sunny autumn morning was no exception. A few minutes before 8.15 he stepped into his building’s express elevator and rode it to his office on the 83rd floor of the World Trade Center’s North Tower. The date was 11 September 2001 and the lives of more than 2,800 men and women in the offices around him were about to be brutally ended. At 8.40 he left his desk to go to the lavatory. On his way he met a group of colleagues and made a sudden decision to stop in a nearby conference room for a chat. While talking, their eyes were suddenly transfixed by the sight of a Boeing 767 passenger jet heading straight towards them through the cloudless blue sky. One of them said in alarmed amazement: ‘Gee, that plane is flying awful low!’

‘It must be a plane from Kennedy that’s got into trouble,’ Fred replied.

Afterwards he recalled: ‘It was all in slow motion. I am told that the plane was flying towards us at 600mph, yet it seemed like an eternity getting to us. I suppose it was 15 seconds. None of us really expected it to hit the building. But it just kept coming and coming. Most of the time it was . . . right in line with the window we were staring out of. Then it was almost on us. I could make out the seams on the wings and all the American Airline markings. I looked right into the cockpit but I couldn’t really make out the figures. They were tiny windows and the sun was shining on them. Maybe I eyeballed Mohammed Atta, the hijack pilot, but I can’t be sure.’

When it was within 200 yards of the building, the aircraft reared up suddenly and banked abruptly to the right. Fred now found himself staring in astonished disbelief at the Boeing’s gleaming silver belly. A moment later, at 8.46 and 26 seconds, the tip of the wing struck the offices some 70 feet above them. It ploughed through floors 94 to 98, smashing steel columns, shredding metal filing cabinets and crushing computer-laden desks. Almost instantly the aircraft’s 10,000 gallons of fuel ignited into a vast fireball, incinerating everything and everyone in its path. So massive was the impact that the aircraft’s landing gear was flung through the south wall of the tower to come crashing down on a street five blocks away. The shock wave from the initial explosion flung Fred and his companions to the ground. Flames and dense black, acrid smoke billowed through the corridors outside the room. Had he still been standing there, Fred would have been killed instantly. But it was not until much later that he appreciated how narrowly he had escaped death. Despite the fact that more than a thousand are thought to have survived the initial impact, not a single person working only seven floors above him got out of the building alive. In the inferno that swept through the North Tower they were either burned alive, suffocated by smoke, killed when the building collapsed or driven by the unbearable heat to leap to their deaths. ‘No one could comprehend it,’ says Fred. ‘I still can’t.’

Corridors filled with dense smoke and flames, shattered stairwells filled with water cascading down from broken sprinkler pipes made escape from the doomed building far from straightforward. In the hallway immediately adjoining the conference room where Fred and the others were taking refuge, the fires had been beaten back by jets of water from the sprinklers and the lights still burned brightly. At 9.30 they suddenly saw a flashlight held by a fireman accompanied by a building worker. Guided by the fireman they made their way down the stairs, stumbling through vast puddles of water and passed by firefighters making their way up towards the blazing floors above them – and to their deaths. As they reached the ground floor a lift shaft shattered into fragments and came crashing down. Ahead of him Fred saw a broken window and scrambled through it to the street. Four minutes later, at 10.28 a.m., the North Tower collapsed. ‘I can’t get away from it,’ Fred says sadly. ‘On our floor there were 15 people killed, ten seriously burned – one of them in the men’s room. If I had gone in there, where I had been heading at the time, I might not be here now.’⁶

Both Fred Eichler and I undoubtedly owe our lives to an impulse. But in neither case was this the result of any sense of impending danger. The next two stories, however, are different. In each an intense if inexplicable fear motivated boy and man to act in the way they did.

The boy in the tunnel

At one stage of my career, while lecturing in clinical psychology and psychopathology at the University of Sussex, I was running a registered charity – Action on Phobias – which helped people suffering from a range of anxiety and phobic difficulties. I also saw patients privately and the two accounts below, with names and certain minor details changed to protect confidentiality, illustrate how a subconscious sense of danger can trigger life-protecting impulses.

Eleven-year-old Tony and his 14-year-old brother Michael lived on a West Country farm managed by their father. The farm had a very large Dutch barn filled, during the summer, with hundreds of straw bales. The two lads had constructed a secret camp by hollowing out a space between the bales in the centre of the barn. This could only be reached through a long, narrow passage between the bales. It was just high enough for a small boy to crawl through on his hands and knees. One night they decided to spend the night in their secret hidey-hole. As darkness fell, Michael wriggled his way in first, pushing their sleeping bags before him. Tony was about to follow when Michael reappeared saying he had left the food for their midnight feast behind in the kitchen and would run to fetch it. Tony decided to go ahead without him. Thirty-four years later he could still remember every detail of scrabbling on all fours along the darkness of the tunnel.⁷ The straw pricking his bare knees, scratching at his arms and brushing his head as he crawled through the musty, straw-scented pitch blackness to their hideaway deep in the barn. He had gone about ten metres down the tunnel when he froze abruptly, suddenly incapable of moving forward. Rooted to the spot by an inexplicable sense of danger. The onrush of fear surprised Tony. He had never previously felt fearful while in the tunnel and was not in the slightest way claustrophobic. On an impulse, and propelled by this unexpected sense of dread, he began a hasty retreat. Since there was no way he could turn round in the narrow passage he had to crawl out backwards. When he was about three metres from the fresh air he saw an orange glow at the far end of the tunnel. A glow that raced towards him at lightning speed preceded by a wall of heat more intense than he had ever experienced. Tony could vividly remembered seeing, in stark detail, the straw forming the roof and walls of the tunnel, all brilliantly illuminated as by an arc lamp. He later learned that his brother had taken a candle into the secret hideout and left it burning while he went back to fetch the food. It must have ignited the straw and started the blaze that destroyed the barn. As Tony scrambled, now in a state of total panic, into the moist night air, a geyser of flame and smoke erupted from the tunnel, singeing his hair and burning his face. Within moments the barn was a blazing inferno. Had he not retreated when he did there can be little doubt that he would have been incinerated by the blaze.

The man who didn’t change trains

Peter came to see me suffering from what, today, we would call post-traumatic stress disorder. A mixture of severe anxiety mixed with guilt, it was the result of a remarkable escape from death he had experienced a year before. On the evening of 18 November 1987, 32-year-old Peter had left his office in central London slightly later than usual and hurried to catch the Piccadilly Line train for the first stage of his journey home. He would travel to King’s Cross station then change to the Circle Line. It was a commute he had done hundreds of times before. The train pulled into King’s Cross shortly before 7.30 and Peter hurried onto the escalator. This would take him up to the ticket hall from which he could transfer to the Circle Line.

The main-line station was, as usual, extremely crowded but everything appeared perfectly normal. As the escalator began to take him towards the ticket hall, however, Peter was suddenly overcome by an overwhelming impulse to go back the way he had come. So intense was this feeling that, ignoring the angry protests of other passengers, he turned around and forced his way back down the escalator to the platform he had left only moments earlier. A train was just pulling out. He jumped on it and collapsed panting into a seat, completely unable to explain his irrational behaviour.

A few seconds after he left the station it was engulfed by fire. Within minutes the whole place was a raging inferno. The ticket hall and the escalator on which he had been travelling were destroyed and 31 people were killed. Many who died were those ahead of and behind him on the escalator from which he had so precipitously and inexplicably fled.

How can we explain such fortuitous impulses? In my own case, I had no particular premonition of danger above the nagging sense of foreboding that was my constant companion while in Belfast in those days. Perhaps it was the contrast between the dark and gloomy December streets and the brightly lit cinema foyer, cheerfully decked out for Christmas, that caught my eye. Maybe it was the prospect of being able to lose myself in a film – of which I can no longer recall even the title, let alone any details of the plot, such was the impression it made – that was so inviting. Certainly compared to the alternative of a solitary supper in a drab restaurant. In his powerful and moving account of escaping from the North Tower, Fred Eichler makes it perfectly clear there was nothing untoward in his mind when he decided to delay a visit to the restroom in order to chat with colleagues. As for Tony and Peter’s life-saving impulses, although they were unable to explain their behaviour, my hunch is that they were responding to the smell of danger, albeit below their level of conscious awareness. They responded instinctively, using what I describe in the next chapter as their ‘zombie brain’, to subtle and virtually imperceptible indications of danger. The fire started by the older boy’s candle, for example, would have been burning for a while before it produced that gush of flame that chased Tony down the tunnel. Similarly, reports show that the fire at King’s Cross station initially started below the escalator. Probably the consequence of a carelessly dropped match or lighted cigarette, it had been burning for some while prior to engulfing the whole place in flames. The fire brigade, who were already on the scene when Peter’s train pulled into the station, believed it posed little or no danger to the public. Although Peter, possibly because he was so focused on getting home, had no recollection of seeing anything untoward prior to his sudden decision to flee, subconsciously he may have smelled, seen or heard something that triggered an alarm bell deep in his brain.

Now of course, had McGurk’s not been bombed that night, if a fallen candle had not turned the Dutch barn into an inferno and had the tragedy at King’s Cross never occurred, then Tony, Peter and I would probably have quickly forgotten our actions. Tony might have been momentarily ashamed of his loss of nerve and probably teased about it by his older brother. Peter might well have occasionally recounted his precipitous flight down the upward-moving escalator with an embarrassed and self-deprecating chuckle. It is most unlikely, however, that any one of us would have long remembered the incident in such vivid – if possibly inaccurate – detail. Which brings me to an important point about impulses. They only ever become significant in the light of subsequent events. Take, for example, the happier impulse that led grandmother Maire McKibbin, from Kilkeel, Co Down, to buy five lottery tickets rather than her usual one. She won over a million euros⁸ with the fifth ticket, making her spur-of-the-moment decision both memorable and newsworthy. Had she had failed to win anything Marie would very likely have forgotten all about it. As William James commented in his 19th-century book The Principles of Psychology, ‘In such cases the strength of the impulsive idea is preternaturally exalted, and what would be for most people the passing suggestion of a possibility becomes a gnawing, craving urgency to act.’⁹

In this book I argue that virtually everything we say and do between waking and sleeping can be considered impulsive in that the vast majority of those actions occur mindlessly rather than mindfully. They result from mental processes operating below conscious awareness. If correct, this means that when it comes to giving in to our impulses we are behaving not as rational human beings but as zombies.

CHAPTER 2

Impulses and Your Zombie Brain

‘There is a zombie within you that is capable of processing all the information your conscious self can process consciously, with one crucial difference . . . your zombie is unconscious.’ Anthony Atkinson, Michael Thomas and Axel Cleeremans, Trends in Cognitive Sciences¹

VISITORS TO MY laboratory, on the south coast of England, often feel disgusted. Or they may become angry, anxious, amused, astonished, frustrated, bewildered, stressed, startled, shocked or sexually excited. It’s all done with their full consent and in the name of science. Our studies are designed to investigate the role of emotions in triggering impulsive behaviours. A typical research project involves ‘wiring up’ our volunteers to record what’s going on in their brain and body during the experience. A network of electrodes are attached to their scalp and connected to an EEG (electroencephalograph) that records electrical activity in their brain. This will indicate the extent to which they are relaxed, by the predominance of relatively slow brain frequencies – known as alpha waves – or cognitively aroused and generating the faster beta waves. Other sensors record changes in their heart rate, respiration and skin conductance. Increases in the latter indicate rising levels of stress. A video camera, focused on their faces, will produce a slow-motion record of their expressions throughout the research, while infrared detectors will track their eye movements on the screen.

When the study starts we see brain activity shifting abruptly, the slower alpha waves being replaced by beta waves as brain activity increases. There is an accompanying rise in heart rate, skin conductance and breathing, the latter typically becoming faster and shallower. To get a flavour for the type of images our participants see, take a look at the two stills in figure 1 from a video depicting self-mutilation.