Emotional Rollercoaster: A Journey Through the Science of Feelings

smiling

‘Cheer up! It might never happen,’ builders like to shout as I walk along the street perfectly happily, not feeling sad, but daydreaming. Irritating though these remarks are, the builders might in fact be on to something. While it makes intuitive sense that exercise might make you feel good, the next topic is more primitive and rather more surprising. Remarkable research has found that we can influence our brain chemistry through something far less taxing than exercise – smiling.

The first person to make a serious study of the smile was the French neurologist Duchenne de Boulogne who determined which muscles were needed to make each facial expression by stimulating each muscle with an electric current. In 1862 he published a book chronicling his findings which included photographs of a man clearly in a state of terror while metal implements were held against his skin. Fortunately for the man, the expression was created purely using the electric current and he could feel no pain because he had a condition which rendered his face numb. Using this method Duchenne studied in detail the muscles responsible for different facial expressions, including smiling. He soon identified the difference between a genuine and a fake smile; the key is a muscle above the eye where crow’s feet form, called the orbicularis oculi. Anyone can fake a smile by raising the corners of their mouth and baring their teeth, but if the muscle above the eye remains motionless the smile looks wooden.

Today the world authority on facial expression is Paul Ekman, who uses his expertise to, amongst other things, train police to spot when people are lying. He’s found that a smile is hard to fake because most people can only voluntarily contract one part of the orbicularis oculi – the inner part which tightens the eyelids. Only 10% of people can decide to contract the outer part of the muscle which pulls the eyebrow down at the same time as raising the cheek and pulling up the skin below the eye. Therefore the way to judge whether a smile is genuine is to see whether the cheeks move higher and the eyebrows tip down slightly. You can experiment by standing in front of a mirror faking smiles. Hopefully you will feel so daft that eventually you smile genuinely and then you can see the difference. Ekman’s other clues to spotting a false smile are that it can be asymmetrical, with a timing that isn’t quite right – either just too early or slightly too late. If the person faking the smile is right-handed, the left-hand side of their mouth will tend to move up more.

The authenticity of a smile can reveal the unexpected. In one study women’s smiles were analysed from a college yearbook. Thirty years on the women with the genuinely happy smiles using the muscle around the eye, were more likely to be married and happy. The researchers did rate each woman’s looks in case the smiley women were simply the prettiest and perhaps therefore the most likely to have found partners, but this wasn’t the case.

It’s not only adults who can fake a smile. Paul Ekman discovered that if a stranger approaches a ten-month-old baby, the baby might well smile, but that smile won’t involve the crucial eye muscle, but if their mother approaches them, it does. Although the baby isn’t deliberately faking a smile, at this young age it can already smile politely.

From the age of four or five weeks babies smile at any human face which nods about two feet away from their face. They seem to want to smile, to engage in communication. This helps the baby and parents to develop a strong bond and is one of the first rewards that exhausted new parents receive for all their hard work. Smiles in very young babies used to be dismissed as wind, but using a new scanning technique developed in London, babies have been spotted smiling in the womb. We can’t prove of course that the baby smiling in the womb is expressing joy but perhaps conditions in the womb vary enough for the baby to feel more comfortable on some days than on others. This has blown a hole in the myth that babies only smile through imitation, although it is true that the more you smile at babies, the more they smile back, just as they will copy other expressions like sticking out their tongues. However, they are born with the ability to smile. In the past it was assumed that babies could experience very few feelings – not even pain – hence the absence of anaesthetics for young babies at one time. Now it is accepted that even a very small baby might be feeling happy.

Joanna Hawthorne, a research psychologist at Cambridge University, works with new parents, encouraging them to judge their babies’ states so that they can choose the right moment for interaction – when the baby is alert but neither too hungry nor too full. It may only last a few seconds but this is the time when an adult and a small baby can take turns in smiling. If a baby smiles at us, we take it as a sign that they like us and we smile and behave warmly back and so the cycle continues.

Smiling also appears to play a crucial role in social interaction between adults. There is a rare condition called Moebius syndrome, where a person’s face becomes paralysed, leaving them unable to smile. One consequence is that they can often find it hard to make or keep friends. This suggests that there is an important social element to smiling, as does the fact that however happy people are with their own company, they smile far more when others are present. In an experiment conducted in a bowling alley it was found that after achieving a strike, people beamed more when they turned to face their friends than at that most satisfying of moments when they watched all the triangle of skittles collapse in a heap.

More recently some Spanish researchers took advantage of the location of the 1992 Olympics to watch twenty-two gold medal winners very carefully, including Sally Gunnell. They observed them while waiting to mount the podium, standing on the podium and turning towards the flagpole while their national anthem was played. They found that people smiled more during the second stage, despite presumably feeling happy that they’d won in the other two stages as well. This the researchers took as a demonstration of the fact that people are more likely to smile when they’re in a social situation rather than when they’re just feeling happy. However, it should be remembered that there are social rules prescribing when it is and isn’t acceptable to smile; one moment when Olympic winners are expected to look sombre is during their national anthem.

The mysterious relationship between smiles and joy has been investigated by Paul Ekman in an extraordinary experiment. Without actually telling people to smile, he gave people precise instructions about which muscles to move, and despite being unaware that they were smiling, the physical process of moving those specific muscles into a smile made people feel happier. In a variation on this experiment the psychologist Fritz Strack gave people a pen to hold in their mouth. The instructed action of holding the pen between the teeth without touching the lips mimicked the movement of a smile, but once again the subjects of the experiment were unaware of the expression they were making.

They were given cartoons to watch and rated them as funnier when the pen was in this position than when they were told to suck the pen with their lips closed around it.

The idea is that the facial muscles are so sensitive that they can feed back their position to the brain and somehow lift the smiler’s mood. This is known as the facial feedback hypothesis. It seems that what we previously thought of as the result of an emotion (a smile) can also be the cause. Even posture can change your mood; sitting upright makes you feel happier than when you’re slumped. It isn’t clear exactly how these processes might work and, indeed, the change in mood usually doesn’t last for long. Is it the case that you become aware that you are smiling which makes you feel good or is it purely physiological?

The nineteenth-century American philosopher and psychologist William James believed that emotions are caused by our awareness of physical sensations and claimed to have used his own theory to work his way out of depression; the more he smiled, the better he felt. Perhaps it is the case that smiling bravely through your tears can make you feel better, in the same way that looking up at the sky if you feel miserable improves your mood slightly, because it’s a movement you would usually make when you are happy. An extension of this theory might explain why we tend to like smiley people. The more they smile, the more we smile back, which could, in turn, make us feel happier.

an experiment

Try this. Stand up and then move your body as though you are laughing uncontrollably. Bend forward, clutching your sides, with your shoulders shaking. You could even introduce the occasional knee-slap. Now try to remember exactly what this feels like physically within your body. Then stand up straight again and imagine that you’re doubled up with laughter, but this time don’t move, just think of those movements. Don’t think of a funny occasion or a joke. Simply imagine that your body is experiencing uncontrollable laughter and then see how you feel.

This exercise isn’t easy, but Nakia Gordon from Michigan State University succeeded in training people to do just this. After three one-hour training sessions, along with plenty of practice at home, most of the volunteers in her studies were able to lie absolutely still in a brain scanner while imagining either laughing, crying or walking. Each movement resulted in a different pattern of brain activation. This experiment shows that emotions can be linked to bodily movements, something William James had thought so long ago. Moreover the people taking part felt happier after imagining laughter, and sadder after imagining crying, even though they were instructed only to imagine the movements, not the feeling of those emotions. This opens up the possibility that it’s not just that smiling can make you feel better, just thinking about smiling or laughing might do the same trick.

the laughing umbrella

On the pavement beside a main road in south London two pairs of legs are visible emerging from a huge yellow tent which seems to hover above the people’s heads and only comes down as far as their knees. The whole tent is shaking slightly and from inside there’s the sound of a person laughing uncontrollably. A few people stop and stare, wondering just who these two people are and what could be going on. Then the tent is lifted off and collapsed like an umbrella. Red-faced with laughter the man thanks the woman with blonde, spiky hair for cheering up his day and walks off up the road, still chuckling quietly to himself. Then the woman approaches another passer-by, introduces herself as the artist Nicola Green, and invites her to come under her umbrella. She is collecting laughter and has found that her customised umbrella provides people with the privacy to laugh while she stands with them making a recording. As a portrait artist she had explored unusual ways of capturing the ‘essence of a person’ by painting a family portrait as the backs of people’s heads or a line of feet. Then she noticed how much a person’s laugh reveals and decided that this was the way to access their joy.

Laughing on cue isn’t easy, as I discovered when I stood in her living room under her laughing umbrella. If you’re passing by in the street then the ludicrous nature of the situation might make it easy, but since I’d arranged to meet Nicola and knew exactly what she was doing, when it actually came to it, I found it surprisingly difficult to laugh. Luckily she has ways of helping reluctant laughers. By encouraging you to fake a ridiculous cackle, she makes you laugh genuinely. She even went on the tube in London, where laughing between strangers simply doesn’t happen, chose a carriage and then shouted out, ‘I want to record your laughter. When I blow the whistle I want you all to laugh.’ Twitching glances crossed the carriage between passengers. Should they do it or not? Could you risk being the only person to laugh? Would it be better to ignore her and hope she moves on? In that split second people make a decision about whether to laugh. She found that either a whole carriage would laugh or nobody would. At Victoria station she somehow persuaded the platform attendants to make a tannoy announcement asking everyone to laugh. Eventually she made her laughter collection into a record, encompassing everyone from her dentist to a vicar in Covent Garden.

It struck me that people often thanked her afterwards for the fun they had had. They clearly felt good, suggesting laughter might provide some sort of physical release. Usually laughing does make people feel better, hence the rows of people happy to sit in laughter clinics, chuckling contentedly. Occasionally, however, laughter does not denote happiness.

the laughter epidemic

In 1962 a very strange thing happened in the village of Kashasha near Lake Victoria in what is now Tanzania. At a small Catholic girls’ boarding school there were 159 pupils. On 30th January three girls began laughing for hours at a time, then crying and then laughing again. Two weeks later they were still laughing. By the middle of March so many pupils were laughing that the school was temporarily closed down. No one knew the reason for the laughter or the tears, but it seemed to be contagious. After the school was closed the girls went to other schools and the epidemic seemed to spread. Soon boys were laughing too. In the village of Nshamba the hysteria spread to more than 200 inhabitants and even to young adults. Soon two boys’ schools had to be closed down for the same reason. Blood tests were taken to test for food poisoning, but everything appeared normal. Six months later people were still giggling – it was a laughter epidemic. The outbreak is often described in works on laughter, usually as a joyful occasion. But it seems it was no laughing matter. Christian Hempelmann from Purdue University in the United States believes that in fact the girls may have been suffering from a mass psychogenic illness of which laughter was one of the symptoms. He believes the condition was caused by the transition occurring in the country at the time. Independence had been achieved in December 1961 and schools were growing with the aim of providing free education for as many children as possible. Hempelmann believes the hysteria might have been a response to the stress of suddenly going to Western-style schools; far from enjoying themselves the pupils were suffering.

Although the researchers who first published details of the case in The Central African Journal of Medicine in 1963 themselves suggested that mass hysteria could be the explanation, it’s intriguing that a humorous explanation has been sought ever since, with writers wondering what the original joke could have been, a joke so good that it apparently made people laugh for months. We seem to have a desire to make sense of our emotions, particularly when they are as intense as uncontrollable laughter. The need to look for explanations was illustrated by the case of a sixteen-year-old girl who was examined in 1998 as part of an investigation into her epileptic seizures. When the doctors applied an electric current to a certain part of her brain she burst out laughing, even when distracted by other activities. It was intriguing that each time she looked for a justification for her laughter, saying how funny the doctors were or that the picture of the horse they had shown her was hilarious. Although joy can be free-floating, when we observe that joy in ourselves we are inclined to look for meaning. Instead of searching for an explanation for individual instances of happiness, perhaps the crucial question is why we have evolved to experience this feeling at all.

the purpose of joy

Everything had been planned for the Saturday night. We were staying with friends in Scotland, the wine was chilling and the lamb was roasting. Everything was in place for us to have an enjoyable evening. Then the host’s mobile phone rang yet again. He was a vet on-call and throughout the weekend we’d become accustomed to his answers which usually seemed to be, ‘It sounds as though your dog has a cough. I don’t think an emergency appointment will really be necessary.’ We assumed this call would be more of the same, but it wasn’t. He rushed out to the surgery at the end of the road, with his wife as assistant. Our main job was to keep an eye on the roast potatoes or so we thought until the phone rang half an hour later. They needed more pairs of hands and we would be able to get there faster than the veterinary nurse. We let ourselves into the surgery, found the operating theatre in the basement and there on the table was a tiny Chihuahua with a transparent tube in her mouth and her insides spilling out of a red slit across her stomach. She was having a Caesarean section. The vet slid his hand inside and swiftly pulled out something that looked like a dead, shaved mouse. As he shook it hard, its head flopped backwards and forwards. To us, with no knowledge of veterinary medicine, it looked as though this might break its neck. Instead it came to life, still floppy with eyes still tightly shut, but coughing softly. Meanwhile we followed his instructions to create a miniature hot water bottle by filling a plastic glove with warm water and took it in turns to rub the tiny creature’s chest continuously to keep it breathing. It was hard work and to us the puppy soon looked dead again, but eventually he could breathe alone. We were ecstatic. By now the mother was coming round. ‘Let’s show her the puppy. Can we put it beside her?’ we asked. ‘You can if you want to, but she won’t care. She’s in shock.’ She woke up, shivering and horrified. She wasn’t quite as thrilled as we were. Unlike the proposed entertainment of a delicious meal and nice wine with our friends, this joy was totally unplanned, but all the better for it.

The fact that unexpected variety can bring such pleasure could indicate one of the purposes of joy – to motivate us to experiment with different activities or places. When we feel scared we are forced to narrow our focus in order to concentrate on the danger, but the opposite happens when we feel happy; our perspective broadens, allowing us to make new discoveries, a skill which may not be essential today, but which would have been useful in hunter-gatherer communities. Experiences of joy also strengthen ties with other people, ties which could be important for survival. Dylan Evans, an expert in artificial intelligence from the University of the West of England, believes that joy could have a further evolutionary purpose; joy advertises our mental and physical fitness. If you are able to pursue joy openly then you must have met your basic needs such as food and shelter, which makes you a more attractive mate.

Some researchers believe that we have a basic brain system for joy, which explains our tendency to take any opportunity to be playful. If you watch people working in an office, provided they have the time and the autonomy, they are ready to take any opportunity to feel joy; they are primed to have fun. I remember a colleague once admitting he could do a one-handed handspring. Then someone else said they could do that dance move from Singing in the Rain where the dancer steps up onto a chair back and lets it tip over backwards until it brings them to the floor. Inevitably the rest of us insisted on proof and we soon discovered that office ceiling fans make handsprings tricky and why actors in musicals avoid using typists’ chairs on castors. When I was a child I remember being very shocked when my father broke his finger in a desk-jumping competition in his office – shocked not that he’d injured himself, but that adults would play in that way.

The first person to win the $100,000 Templeton Positive Psychology prize was Barbara Fredrickson from the University of Michigan. After studying positive emotions for more than a dozen years, she believes that they have a specific role – to ameliorate the effects of negative emotions on the body. To demonstrate this theory Professor Fredrickson first induced anxiety in a group of volunteers by telling them that in one minute’s time they would be required to give a speech which was to be filmed for evaluation by the rest of the group. The nerves soon began to show in their raised blood pressure and heart rates. Then they were given a film to watch which was either funny, happy, sad or neutral. It was found that the people who watched either the funny or happy film recovered their normal heart rates and blood pressure faster than the others, indicating that positive emotions can help to undo the cardiovascular effects of negative emotions. This might explain why certain stressful professions such as medicine become known for the dark humour that often accompanies the work. Medical students working in casualty for the first time are far more likely to recount tales of patients who claim to have fallen onto a peeled carrot while gardening than to concentrate on grisly stories about the appalling injuries they have seen. The deliberate creation of joy through humour works as an effective coping mechanism.

The thought of future joy also has the benefit of encouraging us to plan ahead. One of the happiest moments in my life was the day my best friend Jo passed her driving test. We were seventeen and lived about twenty miles apart, but we knew that her ability to drive would lead to multiple opportunities for potential joy. No longer would we have to rely on our parents or older boys for lifts. To celebrate we set off in her rusty, royal blue Chevette called Cyril, which although old and slow had that essential element – a tape player. With the windows down we sang along to U2 as loudly as we could while driving around the county paying people surprise visits. Despite the fact that we were celebrating a joy and freedom that was yet to come, we felt ecstatic. This ability to imagine happiness in the future allows us to make plans which we hope will end in joy, even if it is necessary to forfeit some fun today in order to achieve them.

There is a children’s story in which the main character is given a choice of gifts – she can have a delicious chocolate fudge cake or the recipe for the cake. The moral of the story is that the wise decision is to go for the recipe because then you can make endless chocolate cakes in the future – in other words, delayed gratification. However, we do soon learn that by forgoing a little joy now – by getting out of a warm bed to go to work, for example – we can experience even more joy later – when we have earned enough to go on holiday.

There is an intriguing theory developed by Michael Apter from Georgetown University in the United States. He proposes that we alternate between two states – the ‘telic’ where we make the effort to pursue serious goals and the ‘paratelic’ where we seek out experiences for their own sake, often in a playful way, regardless of the future. His ‘reversal’ theory suggests that we all switch back and forth between these states, depending on where we are and how we feel. So perhaps the answer to the children’s quandary about the chocolate cake is that your choice of the cake or the recipe depends on whether you are in a telic or paratelic state. Presumably when my father broke his finger he was in the latter.

the route to a happier life?

While research on positive emotions has increased in recent years and the subject has begun to be taken more seriously, the question remains of whether research on happiness can in reality help us to experience this emotion more often. It’s not hard to improve mood in a laboratory. Show people a film of penguins waddling, playing and sliding on the ice and soon everyone feels a bit better. Lying in a flotation tank, singing out loud or listening to stirring music can all lift mood temporarily, but the late social psychologist Michael Argyle wanted to know what gives people lasting happiness. After years spent researching the subject he concluded that the answers lay in attending church, joining sports clubs and watching soap operas. His analyses showed that on average the people who did these activities were the happiest. All three pastimes share both a sense of belonging and of social occasion; even identifying with the characters in a soap opera can induce feelings of belonging in a way that most other TV programmes can’t. In fact, Argyle found that people who watched a lot of television were more unhappy than average. This could be a reflection of the situation which led them to have so much time to spare at home; maybe they were more likely to be unemployed, isolated or unable to afford to go out. Although the people attending church or sports clubs were the happiest, they had of course chosen to join these groups. The research doesn’t demonstrate that if everyone joined they would be happier. If you like neither sport nor religion it could make you more unhappy. When I met Michael Argyle a couple of years before he died his tip for a happier life was simple – to go for brisk ten-minute walk twice a day. People reported feeling better for two hours afterwards, so potentially two walks a day could result in four hours of uplifted mood.

The simple idea of planning activities with the aim of improving mood has been used therapeutically. Unhappy people were asked to keep daily records of both their activities and their moods. Then the lists were analysed to find out what made them happiest and these activities were then incorporated more frequently into their routine. It transpired that people weren’t in fact doing their favourite activities very often, but when they did they felt happier.

However, unfortunately for people who are unhappy, Michael Argyle found that people were relatively stable in their degree of happiness, regardless of what happened to them. A happy person suffering a misfortune might feel temporarily less happy than they were before, but that could still be happier than many people feel despite their lives apparently having gone well. Finding it easy to get on with people and taking exercise were also strong predictors of people’s happiness levels. As for money, becoming richer only makes people happier if the amounts are substantially higher than their expectations of earnings. With all these studies, however, there is the issue of exactly what people mean by happiness when they are filling out a questionnaire. Are they talking about moments of joy or an overall state of happiness? Why is it, for example, that five times as many Norwegians claim to be happy than Italians? Can the differences really be that extreme or are people interpreting the questions differently? Some researchers try looking at the reverse. Rather than measuring how happy people claim to be, they look to see which countries have the fewest suicides, but of course a low suicide rate only tells us that few people are suicidal, not that everybody else is happy.

Joy is perhaps a rather unfair emotion because it is biased towards those who already feel happy. Happy people are better at coping with distressing events; they are more attractive to others; and they find it easy to conjure up happy memories. Moreover, because they feel happy they smile more, sending them on an upward spiral of happiness which, through facial feedback, might reinforce their good mood every time they smile. Meanwhile those who could benefit the most from that extra fillip granted by smiling, aren’t smiling because they feel sad, left on a downward spiral with unhappy memories foremost in their minds. From this perspective it’s hard to see how sadness could possibly be functional, but as we shall see in the next chapter even sadness has its place.

Two Sadness (#ulink_bc820933-b627-5419-8c3e-177b6b4eefab)

Airports are not supposed to be sad places. People are off on ‘the holiday of a lifetime’, ‘a dream honeymoon’ or a gap year ‘finding themselves’. Wherever I’m heading I find myself looking up at the departure screens, imagining which flight I’d board if I could choose: will it be Kuala Lumpur or Moscow, Lima or Nairobi? But this is just my experience. Airports aren’t always happy places.

A woman walks slowly towards the automatic glass doors carrying a soft black bag on her shoulder and a linen jacket wedged in the crook of her elbow. She looks back, slightly embarrassed, aware that others are watching. Lifting her arm, she waves hesitantly at her family who stand with their mouths turned down. Their eyes are already wet. She shows her boarding pass to the man at the desk and walks through the doors ready to snake her way to the x-ray machines. Her family wait for the final glimpse, then put their arms around each other in comfort. For a while they stand still. How long should they wait? They turn and head slowly for the car park, not noticing a young man watching grimly as his pretty girlfriend passes through the same doorway. Will she still be his after a year’s backpacking? A party of ten or twelve are seeing off an elderly Indian woman carrying two vast, checked shopping bags. The toddler is busy running straight into the stretchy barrier and bouncing back off it, but everyone else in the group is crying. Will this be the last time they see her? The stories of all these visitors to the departure lounge are very different, but they’re all sharing the same emotion – sadness.

When someone else read this description they said that imagining those people made them feel sad, but in fact I’d made these stories up. Nevertheless my friend was experiencing that strangely enjoyable sadness you get if you watch a sentimental film. The next time I was at an airport, instead of pondering where to go, I looked around for the sadness and there was plenty. This time it was genuine.

Real sadness, imagined sadness and a slightly luxurious, voyeuristic sadness – this is an emotion which can work at different levels. A little sadness can be quite pleasurable. If you look back at happy times, you might feel sad that a part of life is over, never to be retrieved, but at the same time it’s a warm, nostalgic sadness, free from despair. Melancholy music can have the same effect and we choose to listen to it specifically because it prompts an indulgently enjoyable sadness. In fact over the centuries sadness hasn’t always been seen as a negative emotion. In her work on diaries from seventeenth-century England the researcher Carol Barr-Zisowitz found pride in the feeling of sadness. It was even considered to be the opposite of sinfulness; if you were sad you were seen as patient and wise, despite your difficulties. She also notes that in some societies sadness can have the same effect today. In Iran and Sri Lanka for example a degree of melancholy is taken as an indication of a person’s depth.

Even in cultures where sadness is on the whole perceived to be negative, the absence of this feeling can be seen as problematic. A life spent feeling ceaselessly happy due to the drug soma was part of Aldous Huxley’s nightmare vision of the future in Brave New World. You could argue that if you never felt miserable then neither could you ever feel true happiness. However, we wouldn’t consider a life without illness to be a problem, despite a lack of contrast with good health. In fact when you feel ill the idea of feeling well again seems blissful, but after only a day or two of good health it’s easy to forget how good you feel. Just as it’s hard to appreciate every moment of well-being, it is hard to relish the absence of sadness.

In this chapter I’ll be exploring why a sad face expresses so much and what happens in the brain when we’re feeling sad, as well as the chemical secrets held within that strange symptom of sadness, crying. First it is necessary to understand the purpose of sadness and its close but more complex relation, depression.

the purpose of sadness

‘You just can’t imagine ever feeling happy again. You feel so helpless. There’s just a big void. You can’t even remember what it’s like to feel happy. At first you don’t know what’s going on. You don’t know why you’re crying all the time. You go onto a different level. You can laugh with people, but it’s a superficial laughter that starts in your head and only goes down to your neck.’

When I knew Chloe at school she had always been happy, pretty and popular, but when she was in her early thirties the end of a relationship was followed by a particularly stressful period at work. Suddenly she found herself bursting into tears without warning. ‘When it first happens it hits really hard. You forget about food. It’s too much effort. I remember being upset because my room was untidy but I just didn’t have the energy to tidy it. I phoned my mum and she said she’d come and help me. My bedroom was right next to the front door, but just getting up to let her in made me feel so tired that I had to go straight back to bed. It was very different from just feeling sad, but I think only people who’ve been through it can understand that. Other people think you could do something constructive, if only you tried, but it’s impossible. You feel such a failure and so guilty for not being able to do anything. You just feel useless and you take everything personally. You feel a complete burden, but you can’t even explain it to people properly.’

When depression can become this painful, it raises the question of why sadness evolved at all. Although we vary in our tendency to feel sad, we all feel it, which suggests that it is either an accidental by-product of evolution or that it serves a distinct purpose. It does have to be remembered, however, that evolution takes no account of our pain; natural selection concerns the provision of a life where we can survive long enough to reproduce successfully. The purpose is not to furnish us with a life that’s happy nor even healthy. Despite this, it is hard to see where sadness fits in. It paralyses people, preventing them from succeeding at work or finding partners, let alone reproducing. As we saw in the chapter on joy, a person who feels happy continues to pursue those activities which bring them joy, whether that entails remaining in a relationship or working hard at a job they like. Happiness or even the possibility of future happiness spurs us on. Sadness does the opposite. It can slow a person down to the extent where they stop working; they cease seeking other people’s company; or they even stay in bed. People with clinical depression struggle to find the will to start anything new at what appears to be the exact time that extra energy is needed to make major life-changes. The cognitive scientist, Keith Oatley, believes that we experience strong emotions when we face a crossing point; their purpose is to act as a bridge to the next step in life. Whether or not we decide to change direction is irrelevant. Sadness concentrates the attention, forcing us to stop and take stock. The problem with this theory is that although people do slow down and isolate themselves when they’re feeling sad, they don’t necessarily spend a lot of time deep in self-examination. In one study people were asked how they tended to behave if they were feeling sad. The most popular answers were listening to music or taking a nap. Scrutinising one’s life did not come high on the list.

Taking the idea even further, the American psychiatrist, Randolph Nesse, argues that the function of sadness is to control our energy levels. The idea is that if our chances of success on a project are low, on some level we realise this and start to feel miserable. Then we lose energy and motivation and abandon the project, which saves us from wasting time on something fruitless. It’s even been argued that the treatment of depression with drugs might artificially rid us of a useful emotion.

In some ways this theory does sound plausible, but extreme depression can lead to suicide, hardly an ideal way for evolution to continue the species. In the UK and Republic of Ireland somebody commits suicide every eighty-two minutes. Moreover, not everyone who becomes depressed is following a course which is doomed to end in failure. Sometimes it is the onset of the depression itself which ruins a person’s chances of success. Maybe it’s the case that a little sadness can be useful, but for a few people the system reacts too strongly.