Happiness

by Ed Diener

  Postscript from Ed

  After reading the chapter, you can see why Robert has been called the "Indiana Jones of psychology." Whether it is sex workers in the slums of Kolkata, peasants in southern India, the homeless in California, or the Amish, Robert has surveyed them with gusto - and often lived with them. He has gone far beyond duty in his work, and has been branded, has risked his life kayaking across glacier-strewn water to collect data, and has been harassed by police on several occasions when they were suspicious of his activities. He has eaten dinners in Amish homes and has eaten capybara (a giant rodent) and grubs in the wild. Once when we were interviewing Maasai together, a large cobra brushed his boot as it slithered by in the grass. I have had adventurous research assistants in the past, but none the equal of Robert, and for him I am very grateful - and proud.

  9

  Nature and Nurture: Is There

  a Happiness Set Point, and

  Can You Change It?

  Nowadays many people are concerned about, if not obsessed with, their weight. Some folks are petite while others are a bit ... ahem ... stockier. One of the authors of this book, Ed, comes from a family of - shall we say - "big-boned individuals." These Dieners are the types of folks who are a whopping ten pounds at birth, and keep expanding through adulthood right up to three hundred pounds. At family reunions, there are no exceptionally skinny people, unless they married into the family or were adopted. The relatives are more likely to spend time shopping at the Big and Tall store rather than at Petite Sophisticate. Like many of his family members, Ed struggled with his weight, trying to stay in the same pants size year after year. He dieted and exercised, but it took a lot of effort.

  Then Ed read about "weight set point" - the idea that your genetics are the major determinant of your weight. Some lucky people are born to be thin and others are born to be heavier. With this idea in mind, Ed set about trying to discover his personal weight set point. He ate whatever he wanted, whenever he wanted, and in whatever quantity he wanted. He ate salads, pie, steak, pasta, mustard, ice cream, bread, Chinese and Mexican food, and anything that happened to be appealing. And then some more. Being a carnivore, he avoided vegetables. After all, this gastronomic adventure was his genetic code ringing the dinner bell. During the year of this culinary experiment, Ed gained a pound a week, and ballooned from 208 pounds to 260 pounds! Figure 9.1, below, shows Ed's projected weight, had he not made the very sensible decision to stop the set point experiment.

  Ed continued to put on pounds, and there seemed to be no end in sight. His pants, which a tailor had let out, were getting very tight, and he was worried that he would have to buy a larger bed. Ed took a new tack. He changed his diet and began exercising again, and in two short years he was able to drop back down to his pre-experiment weight, so that he no longer had to wear pants with elastic waistbands.

  Figure 9.1 Ed's weight

  Although you should not try to follow in Ed's footsteps and divine your own weight set point by eating cookies and hamburgers at midnight, there may be an element of truth to the idea of a genetic influence on weight. Certainly, people are born with natural predispositions toward body type, and you can see that some families are muscular, others are lithe, and still others are round. There is some leeway - dictated by diet, exercise, and life circumstances - in how much you weigh, but there are some absolute limits you cannot cross no matter how hard you try. You will never, for instance, weigh as little as an infant or as much as a Volkswagen. Happiness works in much the same way. For years researchers have theorized that there is a happiness set point, some genetically determined level of positivity. No doubt you have heard of the genetic links to depression and how mood disorders are, in part, inherited. Just as our DNA holds the key to a predisposition to sadness and anxiety, scientists have been fascinated by the possibility that there is also a genetic code for happiness. In fact, there are data to support this notion, and the idea of a happiness set point is in vogue.

  You can see emotional set points all around you. When you attend your twenty-year high school reunion, your old classmates seem about as happy as they were back when you walked the hallways together. That enthusiastic, upbeat girl you once had a crush on may have dyed her hair, but she is likely just as positive decades later. And those melancholy kids who lurked in the social shadows tend to grow up to be reserved adults. Even though the lives of your former classmates are very different - they make more money, enjoy the freedoms and responsibilities of adulthood, have children, own a home, work full time, and take vacations - the emotions of your high school alumni are usually about the same as they were back when you were students.

  The idea of a happiness set point is immensely important because it raises so many questions about the pursuit of happiness. If our smiles and optimism are simply a part of our natural physiology, then why should we waste the effort to try to achieve more happiness? Is a genetic basis to happiness a type of emotional fate that none of us can escape? It makes sense to stop and ask whether happiness is genetically determined so that it can resist even our best attempts to live a rosier emotional life.

  The Minnesota Twins and Genetic Happiness

  Minneapolis, Minnesota, is famous for twins. Minneapolis itself is a twin city, sidled up as it is with its sister, St. Paul. Also, the local professional baseball team is called the Twins, and the sidewalks and cafes of the city are full of hats and sweatshirts emblazoned with this single word. But there is another group of twins, perhaps less well known, but certainly no less important. A group of researchers at the University of Minnesota was able, over several decades, to locate and study a large group of twins - some of whom were separated at birth and raised in different households. The twins raised apart offer crucial insights into human nature because they help to answer the difficult question of how much of our personality is the result of life circumstances and how much is the product of genetic inheritance. The researchers studied monozygotic (identical) twins, those who share virtually all of their genes in common, and dizygotic (fraternal) twins, who share about half of their genes. By looking at twins who shared different amounts of genes, as well as similar or different family environments during their upbringing, the researchers were able to identify how much happiness is inborn.

  You may have come across interesting stories about how similar identical twins can be. You may have read accounts of shared hobbies, dressing alike, and even spooky instances of being able to feel each other's pain. You may have heard how even twins who grew up apart marry people with the same name, and wear the same jewelry. We have twin daughters in our family, and it is truly surprising how similar they can be. Not only do they look alike, but they both chose to enter the same profession, both married men named Frank, and often send each other and their parents the exact same birthday cards. When they took classes together in school, they received nearly identical grades on all tests and assignments. Although these examples are possibly just coincidences, compelling data indicate that twins are, in fact, similar in many ways. For instance, twins show impressive similarity on standardized tests of personality, intelligence, and emotion, which cannot be due to coincidence.

  The research team in Minnesota found a number of striking findings in their study of twins. They found genetic links to a variety of surprising behaviors, ranging from church attendance to a preference for recreational hunting! But some of the most compelling data concerned the twins' emotions. The genetic factor turned out to be so powerful that the identical twins who were raised in different households were more similar in their emotions than were fraternal twins who were raised together! If one identical twin was generally positive, the researchers found that there was a high likelihood that the sibling on the other side of the country would be as well. These findings point to the importance of genes in how happy we are, and other researchers have replicated this finding. For example, a Danish team used twins as participants in their research to analyze how variable happiness is over time. They were intereste
d in how much people's moods naturally bounce up and fall down from their own personal happiness average. The Danish researchers estimated that about a quarter of variability in happiness is based on direct genetic factors.

  Additional support for a genetic link to happiness comes from the study of personality. Take the example of personality types, which have been shown to be substantially inherited. Some folks are natural social butterflies and others are wallflowers. Some people are imperturbable while others are hotheaded. Two personality factors that have received focused research attention are extroversion and neuroticism. Extroverts are reward-seeking, sociable people, while neurotics are more prone to worry, guilt, and sadness. Neurotic people, almost by definition, score lower on measures of happiness. The research psychologist Richard Lucas has studied personality and emotion and concluded that, in cultures around the world, extroverts tend to experience more positive feelings, as though they are prone to this by biology. Even in controlled confines of laboratory studies, researchers find that extroverts tend to report more positive reactions to experimental stimuli, but mostly they are just a bit happier even when they arrive at the lab. It is not that introverts are unhappy - many of them are happy - it's just that, on average, they feel fewer positive emotions, and feel them less intensely than extroverts.

  If your happiness is, in part, a product of your genes, it makes sense to ask what is happening at the biological level that affects your positivity. Neuroscientists, physiologists, and other researchers are beginning to identify specific genes that can influence good moods. For example, a research team at London's King's College followed kids over the course of many years from childhood to adulthood. The scientists tracked the kids' DNA, as well as their life circumstances and social backgrounds. The researchers were able to isolate a single gene, 5-HTP, and identified one of the variations of this gene as a factor in depression. The gene influences how serotonin - a neurotransmitter - is processed by the brain. Serotonin is the same brain chemical that is acted upon by common antidepressants, such as Prozac. Completing the scientific loop, researchers have shown that people with the specific allele of the 5-HTP gene react more in emotional areas of the brain, such as the amygdala, when they are shown disturbing pictures, and ruminate more in response to stress. Thus, one likely reason that there is a substantial influence of your genetic blueprint on your happiness is that genes influence how the brain processes mood-related hormones in emotion areas of the brain.

  There is a connection between our DNA and our levels of happiness, and we even have some insight into the specific mechanisms of that connection, such as 5-HTP. How strong is the relationship of genes to happiness? Does your genetic code entirely determine your happiness? How much of your well-being can be chalked up to chance factors and your personal choices? The Danish research team gave an estimate of 22 percent, while the Minnesota team says as much as 50 percent of happiness could be inborn. You may have heard these types of percentages thrown around by experts talking about the nature versus nurture debate. One common story is that about half of our moods, choices, values, and behaviors are due to environmental influences, and half can be chalked up to genetic inheritance.

  The truth is, there is no easy way to give a simple percentage when talking about what makes humans feel, think, and act the way they do. In the London study, the 5-HTP gene and a difficult environment were needed in combination to produce depression. To complicate matters further, life circumstances (nurture) and genetics (nature) affect one another. If you inherit your grandfather's foul temper, your father's good looks, or your mother's fantastic memory, these inborn qualities will influence your relationships, job, education, and interactions with strangers. On the other hand, our environment can also affect our genes. The emerging field of epigenetics shows that the expression of our DNA codes is affected by our environments in producing who we are.

  Some specific genes only get expressed under the right environmental circumstances; otherwise they lie dormant. In a study of mice, for example, exposure to toxins during pregnancy affected not only the fertility rates of male offspring, but also their descendants down through four generations. In one study of life satisfaction, genes predicted more about the happiness of rich people, whereas for poor people, variations in environment had a bigger influence. If the impact of the environment varies depending on life circumstances, then the percent due to genetics also varies. Thus, genes and environments interact to affect important bodily processes, including those related to happiness. It is not possible to pin a universal percentage on genetic influences, because genes and environment influence each other, with the environment sometimes switching on or off the expression of particular genes. Although there is no such thing as a true number indicating the amount of happiness due to genes, we can say with confidence that both genes and environment are important.

  Despite the exact figures or proportions, it is still important to understand the extent to which genetics matters to happiness. Genes do seem to be a powerful influence on emotion, but surely, there must be limits to the power of our DNA. After all, even a happy temperament can be unhappy in a bad situation. Even the most naturally upbeat person can get irritated over an insult, disappointed when her team loses the World Cup, or sad when his child has an emergency appendectomy. So why aren't people in terrible neighborhoods chronically depressed and people in the affluent suburbs routinely positive? The answer lies in the amazing human capacity for adaptation.

  Adaptation: The Force Pulling Us Back to Baseline

  Chris Ware, the creator of the popular Jimmy Corrigan comic series, has a superpower. Or at least he thinks he does. Ware, who was interviewed on the Chicago-based radio show This American Life, admitted that when he was a kid, he desperately wanted to be a superhero, and was vigilant for signs of developing powers, such as flight or invisibility. Then, one day, his dream came true. He was taking a shower in warm water, and noticed that, as the shower continued, he was able to turn the handle and make the water hotter and hotter. He was amazed to see, by the end of the shower, that he could withstand even the hottest temperatures. He appeared to be nearly invulnerable, able to withstand even scorching heat. He was delighted!

  Of course, you and I (and hopefully, Chris) know that there was nothing extraordinary about that shower. The hot water simply ran down while Ware's body adjusted to the warmer temperatures. The same process happens in the first few minutes in a swimming pool, which can feel torturously cold at first, but later feels fine. Happiness works in much the same way. People are built with the natural ability to adapt to new levels of joy. All of us can experience the emotional highs that come with buying a new car or reading a child's outstanding report card, and each of us is familiar with the emotional troughs that come with chronic illness, remodeling the house, or getting arrested (okay, well maybe only a few of us are familiar with getting arrested). But ask yourself: Why don't you stay that way? Why aren't you as happy today as you were on the day of your promotion at work, or as sad as you were on the day your grandmother died? It is not simply because new events - both happy and sad - have occurred in your life. It is because you adapt to the new conditions over time. This is why so many folks seek out novel experiences, look forward to a change of pace, or develop new goals once old ones have been met. We tend to react to changes, and then quickly adjust to the new circumstances.

  The influence of adaptation on happiness was identified by wellbeing researchers in the 1970s. In their classic article on the subject, Phillip Brickman and his colleagues suggested that most people experience "hedonic" neutrality over the years, with only occasional emotional spikes and valleys. That is, with the exception of a few potent events that temporarily raise and lower happiness, people tend to be relatively even-keeled where happiness is concerned. Tough times bring us down and joyous occasions are uplifting, but we quickly adapt to both.

  This means, in essence, that people who try to make themselves really happy - those folks who chase excitement in
relationships, a big paycheck at work, and intense thrills in their leisure time - are a bit like rats on a treadmill, running and running, but not really getting anywhere. You probably know people like this. These are the kind of people who thrive on pressing deadlines, social crises, constant novelty, and thrill seeking. The problem is that pay raises, new lovers, new jewelry, and new jobs can all seem exciting and rewarding at first, but over time you adjust, and their emotional luster dims. What was once thrilling eventually seems no more than mildly pleasant. Brickman called this phenomenon - the idea that people can chase emotional highs but adaptation will drag them back to a neutral mood - the "hedonic treadmill."

  When they first introduced their theory of the hedonic treadmill, Brickman and his colleagues thought that people adjust back to neutral, emotionally speaking. Later research showed that this was not the case. Closer to the truth is that people adapt idiosyncratically, with each individual adjusting back to a unique set point. Some folks are exuberant extroverts and others are more morose. Most of our set points are somewhere in the mildly positive range, and this is the place to which we will naturally return when there are no extraordinarily positive or negative events taking place in our lives. Mildly pleasant happiness is like our resting heart rate or blood pressure. This makes good evolutionary sense. Mild feelings of positivity give us just the boost we need to be motivated, seek out friends, take appropriate risks, and persevere at difficult tasks. But seeking out the Shangrila of continual intense happiness is a prospect doomed by adaptation.