When Dave entered early adolescence, he suddenly developed a severe form of social anxiety. He was afraid to speak in class, he wouldn’t show up when he was supposed to present, and his grades dropped. Slowly, his friends disappeared. Not only did he no longer have social anxiety, he also became extremely lonely and withdrawn.

“I remember feeling bad most of the time and being afraid to be around people,” Dave told me when he first spoke to me in my lab at the University of Miami.

As Dave progressed through his teenage years, his anxiety and withdrawal grew. He told me that it was like standing behind a thick glass window when he spoke to others, no one listening to him, not even being able to hear what others were saying, just being inside himself. His responses to other people’s questions were brief and dismissive. His voice was monotone.

As Dave entered young adulthood, he decided that he could no longer stand his isolation. Something had to change. But what? Could one simply change one’s personality? Dave didn’t think so, but he tried everything he could to act in ways that were inconsistent with his personality. Despite his low GPA, he managed to get into college—a college that was a long way from his hometown of Seattle: Miami-Dade Community College. He deliberately sought out people and all the parties he could find. He also started drinking heavily.

Partying and drinking didn’t make things any better. They made them much worse. But Dave kept trying to force himself out of his introversion, trying to seem like the person he wanted to be but wasn’t: a fun, outgoing, talkative guy.

But he wasn’t that person. He never felt like himself when he was performing. He felt like he was failing, and he considered dropping out of college. He thought maybe he was born the way he was: an introvert who was never satisfied with life, who always saw the glass as half empty.

But he didn’t give up. He gave up drinking and partying and started exercising and living a healthier lifestyle. After reading several self-help and psychology books, he also started meditating. He began to feel less anxious, but he still felt unhappy and dissatisfied with his life.

When he first came to our lab, he was a control subject for a personality study. The only problem was that we couldn’t use him. We were looking for a control subject. Control subjects in personality studies are people who score average on personality scales. Dave didn’t score average. He scored very high on a pessimism scale. The good news was that we could use him as a research participant, not a control subject.

In our study, we were looking at whether you could change your outlook on life, using a simple computer test that required you to look for happy faces among negative ones. Dave was scheduled to continue practicing the exercises daily.

Eight weeks later, Dave returned with his notes about his personality tests. At first, we barely recognized him. His personality seemed to have completely changed. For the first time in his life, he looked at life through rose-colored glasses. For the first time since childhood, he felt like he was finally the person he had always wanted to be. He even started dating a girl in his class. His grades were going up.

Dave had changed his personality. And personality tests revealed it.

Dave smiled and said, “I didn’t think that was possible. Now I think I have objective evidence.”

What Dave referred to as “objective evidence” was a psychological questionnaire. They are based on self-reports. Questionnaires aren’t meant to determine how you act in certain situations. They’re meant to determine your personality traits. In psychology, the standard model of personality types is the Big Five. People are classified in terms of degrees of extraversion (or introversion), neuroticism, openness, agreeableness, and conscientiousness. Each of these five traits is made up of several other, more specific traits. [1] For example, the neuroticism dimension is made up of aspects such as anxiety, depression, self-consciousness, and vulnerability to stress. You can score high or low on any of these aspects, based on your answers to a large number of questions that assess how likely you are to act in certain ways in certain situations.

Personality disorders, such as depression, post-traumatic stress disorder, and antisocial personality disorder, can be explained on the Big Five model as states of personality that fall at the end of a spectrum on several aspects. Individuals with antisocial personality disorder, for example, are people who score low on agreeableness and conscientiousness.

Personality disorders are usually only discovered when people’s behavior deviates so far from the norm that they become dangerous to others, have difficulty getting along with others, or are unable to function. Dave didn’t have a personality disorder. Most of us don’t—certainly not to the point where we need a professional or clinical diagnosis and treatment. We simply fall somewhere in the middle of the spectrum on the five dimensions. Yet small deviations can sometimes have a huge impact on how we relate to others, whether we’re able to have successful relationships, and whether we’re able to climb the career ladder. Most of us have had the idea of ​​having a different personality at some point in our lives. Like Dave, we may wish we were more outgoing, more resistant to criticism, more optimistic, less impulsive, and less socially awkward. For most of us, this is just wishful thinking—because most personality theories tell us that our basic personality type is fixed for life. Sure, we can modify some habits and modify our behavior, but we can’t change who we are on the inside. Once our brains reach maturity after the teenage years, the prevailing belief is that this is all there is to it—our basic identity is fixed. As Dave’s story attests, this belief, however, turns out to be deeply rooted in old ways of thinking.

ThePlasticBrain

Recent findings on neuroplasticity show how the brain can modify its structure and function in response to changes in the body or the external environment.

A stunning testament to the brain’s ability to change and recover is the case of Jodie Miller. [2] After her third birthday, Jodie began having severe seizures that left her body shaking for hours. All of the seizures came from the right hemisphere and spread to the entire brain. It wasn’t until several months later that she lost control of almost all of her left leg and arm. She would convulse and fall every day, risking a serious brain injury.

At this point, doctors presented her parents with a startling choice. The only way Jodie could survive with any sense of normalcy was to surgically remove half of her brain.

The procedure was long and complicated, as doctors worked to separate the two halves of the brain without damaging the brain stem, which maintains basic life functions like breathing and sleep-wake cycles. The operation took seven hours. But it went as well as anyone could have hoped.

After surgeons removed the right hemisphere of Judy’s brain, the space filled with cerebrospinal fluid. Her brain began to reorganize almost immediately after the surgery. Although the right hemisphere had been responsible for the left side of Judy’s body before the hemisphere was removed, what remained of her brain quickly learned to control both sides of her body. Four weeks later, Judy was able to walk out of the hospital on her own. Her left brain was performing all the functions of a normal brain in just four weeks!

It would be very strange if personality were the only thing that escaped the brain’s amazing ability to change. But personality is rarely considered from the perspective of the brain. That’s probably the main reason we say it’s fixed for life. If you study personality, you’re primarily interested in how people behave in different situations. If you study cognition and the brain, you look at how people think and feel and how their brains work to produce these thoughts and feelings. These are very different approaches that are rarely combined and rarely lead to common discoveries.

Behavior is crucial to understanding what a normal person is like, but it only reveals one aspect of personality: what others can see. The other important component is what’s going on inside your skull. The things you can’t always see. People trapped in unresponsive bodies are harrowing testaments to the fact that what’s going on inside a person can’t always be measured by looking at behavior.

UnlockingPersonality

Scott Routley was studying physics at the University of Waterloo, Ontario when his promising future suddenly came to a halt. On December 20, 1999, Scott was leaving his grandparents’ house in Sarnia, Ontario, with his girlfriend. Just a few blocks away, they were struck by a police car. His girlfriend and the police officer were taken to hospital for treatment of minor injuries. Scott suffered more dramatic injuries that left him in a bizarre state of unconsciousness, also known as a persistent vegetative state or unresponsive wakefulness syndrome.

PVS is different from coma. In a coma, a person appears asleep and motionless, their eyes are closed, and the results of an electroencephalogram (EEG), which detects electrical activity in your brain, are similar to those of a person under general anesthetic. People in a persistent vegetative state go through regular sleep-wake cycles. When they wake up, their eyes are open and they may look around. To the untrained eye, they appear conscious and responsive, but sadly most are not. Persistent vegetative states can last for years, and when people regain consciousness, they are largely paralyzed.

This was the state in which Scott was left after the accident. His parents insisted that he was responsive to them, but all the conventional methods of detecting consciousness suggested that he was not conscious and that his parents were interpreting too much into his eye movements and body twitches.

Twelve years later, British neuroscientist Adrian Owen heard about Scott Routley in 2011. Owen had previously discovered minimal consciousness in patients in a persistent vegetative state using functional magnetic resonance imaging (fMRI). Functional MRI shows where the brain is most active when a patient looks at a stimulus, listens to it, or performs a simple task.

After hearing Scott’s parents insist that Scott was conscious, Owen decided to test their claims. Owen’s team first tested whether they could find distinct activation patterns in Scott’s brain in response to two different commands: The first asked Scott to imagine walking through his house, through each room, and checking out certain objects in his paths, such as the refrigerator, the dining room table, and the television. The second asked Scott to imagine playing tennis, sprinting across the tennis court to get the balls. The results confirmed the parents’ suspicions. Both tasks elicited distinct patterns of brain activation. When the team asked Scott to imagine walking from room to room in the house, the parahippocampal gyrus, which helps us navigate through space, lit up on an fMRI scan. On the other hand, when they asked him to imagine playing tennis, the motor cortex lit up. This area of ​​the brain tells the motor cortex which muscles to move. The fact that Scott could consistently execute a command and imagine one of two very different scenarios proved that he was not just awake, but conscious.

But Owen wanted to know how conscious Scott was. Was Scott aware of himself? Did he recognize his family members and caregivers? Was he in pain? Did he have any entertainment preferences? Owen wanted answers. Since functional MRI scans cannot detect the difference between someone thinking “yes” and “no,” Owen’s team used a special paradigm that translates “yes” and “no” into two different visual scenarios. Scott’s “yes” scenario was to imagine himself walking through his house. To answer “no,” he had to imagine himself playing tennis. Because these two scenarios produced distinct brain activations that could be detected in the scanner, Owen was able to read the answers to his questions from Scott’s brain. The tests revealed that Scott knew who he was and that he was in the hospital. He was also able to identify the name of his personal support worker and the current date. When asked if he was in physical pain, he answered “No.”

Scott had been buried alive inside his unresponsive body for twelve years before his voice was finally heard. But for those twelve years, Scott was there, kicking and screaming, yearning to be heard. Only functional magnetic resonance imaging (fMRI) scans could reveal that he was still there. He was not only awake, but fully aware of his surroundings, able to imagine complex scenarios, make difficult decisions, and answer difficult questions. Cases like this underscore how important the brain is to personality. What happens inside the brain can make the difference between being a breathing “vegetarian” and being a person with multifaceted inner qualities and characteristics.

Awakening Dormant Brain Circuits

Genetic research, particularly twin studies, suggests that personality is 50 percent inherited and 50 percent due to non-genetic factors. That means if you’re born with a certain set of genes, you have a 50 percent chance of developing a certain personality. But you also have a 50 percent chance of not developing it. You’re just predisposed, not destined to be a certain way. The environment is only half the equation. A child’s personality is still being shaped and reshaped in dramatic ways. The same is true for teens and young adults, whose brains are still undergoing dramatic transformations.

While the brain continues to change throughout your life, the greatest number of transformations occur before puberty. Before puberty, the brain is constantly generating new neurons, new neural connections, and myelin, a fatty substance that wraps around the conductive ends of neurons and makes them better able to communicate with other brain cells. As the brain grows, it not only creates new connections, it also sheds ones it doesn’t use. This process of pruning neural connections is also known as pruning, or just pruning. Pruning is thus a process that changes the neural structure by reducing the total number of neural connections, or synapses. This results in more efficient synaptic configurations. Pruning is primarily driven by environmental factors, especially learning. The brain can also change its wiring differently. In pruning, neurons don’t die. It simply pulls the nerve endings, or axons, from synaptic connections that aren’t useful. But the brain can also rewire itself by killing its neurons in a process called apoptosis, a form of programmed neuronal death that’s different from the kind of neuronal death that occurs in brain injuries, like when you’re knocked unconscious by a baseball bat. In apoptosis, a neuron is killed and all of the connections associated with the neuron are also severed. Apoptosis occurs, for example, when the brain regenerates at regular intervals, or in more extreme cases when cancer cells induce healthy cells to undergo this process.

During childhood and adolescence, the inaccurate, unused, and unnecessary neural connections between neurons are gradually pruned away, leaving behind stronger, more useful, and more specific connections. We can think of this as a kind of neural natural selection.

It is during this time frame that our most stable personality traits are formed. However, this raises a puzzling question. Once a neural connection or brain circuit is pruned, it is gone forever. Doesn’t this suggest that it is difficult to change things once we reach adulthood?

There is some truth to this. Once we reach adulthood and have a relatively stable set of personality traits, it is difficult to change them. We cannot regain what we have lost in the pruning and trimming processes. In some cases, genetically based brain abnormalities make it almost impossible to change. People with Williams syndrome, a genetic disorder caused by the deletion of 26 genes on chromosome 7, are very outgoing: they have a cheerful demeanor, are talkative, and feel comfortable with strangers. Recent studies show that Williams syndrome results in a disruption of the structure and function of the anterior insula, a region of the brain involved in self-awareness, empathy, and personal experience. [3]

While childhood is undeniably a window of opportunity for change, it has now been shown that the adult brain can also change. It continues to do so throughout life. It can transform in new ways with learning. But it can also revert to old patterns. For better or worse. That’s because the pruning and trimming processes aren’t always complete. Sometimes neurons are left intact but have lost many of their connections to other neurons. In other cases, the connections are still there but have become dormant. This means that the information the neurons transmit is so weak that it’s no longer enough to move muscles or to reach consciousness.

The amazing thing is that even paralyzed neurons can regenerate connections with other neurons, which can reboot dormant brain circuits. One of the most astonishing discoveries of brain plasticity in recent times is that people who have been partially paralyzed due to spinal cord injuries can regain some movement by manually reawakening the connections between the spine and the brain. Complete and persistent paralysis was previously thought to be the result of a disconnection between the spine and the brain. But researchers at UCLA, UCSF, and Russia’s Pavlov Institute discovered that in patients they were examining, the spinal-brain connection was still there, but in a dormant state with barely any neurons firing. [4] By stimulating nerve pathways in the spine with electricity, the team found that they could restore some movement to people who had been told they would never feel their limbs again. These changes are physical, but awakening dormant brain circuits can also lead to psychological changes. One of the most extreme cases was recounted by neurologist Oliver Sacks in his 1973 memoir, Awakening, in which Sacks describes his discovery of the beneficial effects of the then-new drug L-dopa on cerebral palsy patients. In 1969, Sacks gave the drug—a precursor to the brain chemical dopamine, which is responsible for motivation and pleasure—to patients at a Bronx hospital suffering from encephalitis lethargica, an inflammation of the brain that destroys dopamine receptors and often leaves people speechless and unable to move. The Bronx patients had been victims of an epidemic of the condition between 1915 and 1926 and had been in a sleep-like coma for decades. When Sacks gave his patients the drug, it overactivated the remaining dopamine receptors, triggering the brain circuits for movement and speech. His patients woke up and returned to some degree of normalcy.

When you awaken dormant brain circuits, you alter the function of existing neural pathways. But the brain can also change by generating new neural connections, or synapses. These changes are known as structural changes. When people take up a new field of study or line of work, dramatic structural changes occur in the brain’s neural connections. For example, when people start using smartphones, the areas of the brain that control the fingers and thumb change. In one study of 37 volunteers, scientists found that smartphone users had larger brain activation readings in response to mechanical touch on their thumbs, index fingers, and middle fingers than did users of traditional cell phones. [5] Similar adaptations have been found in the brains of musicians: The areas that dominate the fingers used to play the violin are significantly larger in violinists than in non-violinists. The ability of the adult brain to change its structure is amazing enough, but the biggest surprise was that the adult brain generates new neurons. I was warned throughout my teenage years that neurons lost to drinking and recreational drug use were gone forever. But that turns out to be not true—certainly not for neurons in the main memory-control area, known as the hippocampus, or for some other areas of the brain. The brain is capable of converting stem cells, which are cells that are not specialized in anything, into neurons and incorporating them into existing neural networks. In recent years, we have discovered more and more cases in which dormant brain circuits are reactivated, sometimes in the strangest ways. When George Melendez was ejected from his car after a tragic car accident, he was left in a minimally conscious state. He was vaguely aware of his surroundings but otherwise unresponsive. His family took him home to care for him. Because of some nightmares that kept George tossing and turning at night, the family doctor prescribed zolpidem, known commercially as Ambien. The sleeping pill had the opposite effect. It didn’t help George sleep. It woke him up. He was suddenly able to talk and remember everything from before the accident. After a second dose of Ambien in the morning, the feeding tube was removed and he ate pancakes for breakfast.

In another case, a 48-year-old woman was left in a minimally conscious state for two years after a suicide attempt. [6] She couldn’t move, talk, or even feed herself. When Ambien was given to help her sleep, she was suddenly able to talk, eat, and move around on her own until the drug wore off. This wasn’t an isolated incident: Researchers have encountered many other cases of paradoxical awakening, suggesting that Ambien can over-activate dormant brain circuits in some people with brain injuries.

While medications can sometimes stimulate dormant brain circuits, less invasive techniques can achieve similarly dramatic results by mimicking the effects of drugs. It’s long been known, for example, that severe sleep deprivation relieves depression 60 to 70 percent of the time, better than common antidepressants. But for years it’s been unclear how extreme fatigue can pull us out of a state that normally makes us want to stay in bed all day.

The electrical signals of the sleep-deprived brain have been shown to mimic those of the emergency antidepressant ketamine. Ketamine—or “special ketone” in street lingo—is used to induce anesthesia before surgery, but in very small doses it can temporarily relieve severe depression by increasing levels of glutamate, a powerful neurotransmitter that activates the brain. [7] The release of glutamate quickly reconnects neurons damaged by depression. When we feel sleepy, the brain naturally releases the chemical adenosine. While this chemical normally puts us to sleep, in larger amounts, it can protect the brain from the damaging effects of sleep deprivation. It does this in a similar way to ketamine, by altering activity in the prefrontal cortex, which can temporarily relieve symptoms of depression.

The unexpected awakenings caused by Ambien or adenosine are generally not a useful way to wake up dormant brain circuits. However, they add weight to the suggestion that dormant brain networks can be reactivated.

The Extraverted Person in You

How does the process of awakening the brain circuits in quadriplegics, people with minimally conscious states, and people with severe depression relate to the brain circuits responsible for personality? Research shows that many of us have dormant brain circuits for personality traits that are so weak that they do not influence our actions, emotions, or thoughts. You can see this process at work in people who have had recent traumatic or transformative experiences. If you were an extrovert in the past and have recently become an introvert due to a bad breakup, layoff, or loss of a loved one, you are likely to have dormant circuits that correspond to your old extroverted personality.

This chapter will focus on extraversion. In subsequent chapters, we will look more closely at other personality types as well as some common personality disorders. Remember, extraversion is one of the five dimensions of personality in the Big Five model of personality, one of the most widely used models of personality in personality psychology. We often attribute extraversion to people who are social magnets, the center of attention at social gatherings, the people who can spontaneously give a great toast at their friend’s birthday party, and who don’t care what people think of them. But like the other dimensions, extraversion is made up of six facets, only some of which relate to everyday behaviors, and none of which relate directly to whether you care what others think of you. The six facets of extraversion are warmth/friendliness, agreeableness, assertiveness, activity level, excitement seeking, and positive emotions/playfulness. Someone who makes friends easily, who thrives best in the company of others, who has a dominant style, who has few empty spaces in their busy schedule, who feels most alive in highly stimulating environments, and who radiates joy will score high on all six facets of extraversion. Most people fall somewhere in the middle of the spectrum, either scoring in the middle on most facets or scoring high on some facets and low on others. Even though most of us aren’t extroverts, extroversion has become something of an ideal in our society. As former Wall Street lawyer Susan Cain argues in her book Quiet: The Power of Introverts in a World That Can’t Stop Talking, we’ve always been a society that favors action over contemplation. Our education system encourages extroversion by putting kids in large classes and encouraging group activities and social behavior, to succeed in the workforce, being attractive, and charismatic, and speaking up and taking charge are powerful assets. To succeed in our society, introverts often have to pretend to be extroverts or work hard to overcome their aversion to the spotlight. In her book, Cain draws attention to the many societal values ​​that are ignored by introverted loners. People who are thoughtful, intelligent, and well-read are often the ones who do the basic research that big corporations benefit from. Yet the fact remains that in many areas of society, being extroverted gives you the push that is sometimes needed to get your foot in the door of success. But boosting your openness turns out to be within the realm of possibility because this dimension of personality is seated in the parts of the brain most susceptible to change.

Optimism and Environmental Pleasure

The six facets of openness are supported by two other key traits: (realistic) optimism and the tendency to attribute pleasure to the environment.[8] Countless studies have found that optimism is associated with high self-esteem, a cheerful attitude, a tendency to look at the positive aspects of a situation, and a belief in a bright future.[9] They see themselves as responsible for their success and accomplishments rather than as passive agents whose successes are the result of luck. This mindset boosts happiness.[10] It can even add years to your life.[11] In a recent study, Sophie Chou, an organizational psychology researcher at National Taiwan University, found that a healthy amount of optimism can also lead to life success.[12] A sense of realism can help us perform well at work and school, and a positive outlook can help us spot opportunities and compensate for depression after failure or rejection.

Realistic optimists are more likely than pessimists to project genuine joy, friendliness, and warmth, two aspects of openness. Surprisingly, optimists and pessimists have distinct brain activations that can be measured using electroencephalography (EEG), which detects brainwave patterns in different parts of the brain. Optimism turns out to be associated with greater physiological activity in the left frontal hemisphere of the brain, while pessimism leads to greater activity in the right hemisphere. In people who fall in the middle of the optimism/pessimism spectrum, the brain receives and processes positive and negative information to roughly the same degree. However, the left hemisphere is more active when positive information needs to be processed, while the right hemisphere struggles to function when the input is unpleasant or negative. [13] In one experiment, research participants listened to a recording of a message warning them about the harmful effects of the sun through either their left or right ear. [14] Information coming through one ear is processed on the other side of the brain. The researchers found that those who received the message through the left ear and thus processed it in the right side of the brain were more likely to use sunscreen at the beach. In other words, they were more likely to be cautious about sunburn because the message was delivered to the “cautious side” of their brains.

This discrepancy between the two sides of the brain can also be detected when people on the average spectrum process information about their positive versus negative traits. [15] For example, if people with a bad temper but who are hardworking think about their anger, the right hemisphere of the brain is more active, and when they think about how hard they are working to achieve goals, the left hemisphere is more active.

The sustained high activity in the left hemisphere of optimists is explained by their tendency to look on the bright side of life and see themselves in a positive light and as active agents. Pessimists have shut down parts of the left hemisphere that are supposed to absorb and process the positive aspects of themselves and their surroundings and are responsible for their success. One form of depression is a pathological or extreme state of pessimism. [16]

A second trait underlying openness is the tendency to attribute internal feelings of pleasure to one’s surroundings and to active and social environments to trigger feelings of pleasure. A study published on June 13, 2013, in Frontiers in Human Neuroscience, found that extroverts are more likely to attribute the release of the reward chemical dopamine and motivation to the environment in which they are. [17] Researchers Yu Fu and Richard Depue, neuroscientists at Cornell University in New York, gave a mix of extroverted and introverted research participants Ritalin, a drug that increases active dopamine levels in the brain. While under the influence of the drug, the participants were shown neutral videos, such as a rainforest, or stimulating videos, such as videos of a winning soccer match (a goal being scored). Later, the participants underwent tests to measure how their increased attention affected feelings of reward, using memory tests and tests of environmental stimulation, such as finger tapping and behavior. Unlike introverts, extroverts associate their increased attention to the videos with feelings of energization. They attributed their good feelings to what they saw outside themselves. All of this suggests that extroverts feel energized by rewarding environments, whereas introverts are more likely to be “high” by what’s going on in their minds.

The sociability and thrill-seeking aspects of extraversion are directly attributable to this tendency to find pleasure in a stimulating environment. Extroverts tend not to stay home because home doesn’t provide the kind of stimulation from which they draw energy. And because dopamine-driven pleasure is the antidote to anxiety, shyness, doubt, and timidity, an environment that fosters this kind of pleasure can also foster boldness, assertiveness, and a sense of responsibility—the sixth aspect of extraversion.

Motivating Openness

Research has shown that optimism is rooted in what is known as attentional bias.[18] Attentional bias is a general tendency for thoughts we typically experience or enjoy to influence what we end up processing in our perceptions. For example, people who think a lot about clothes and fashion pay more attention to what other people are wearing.

Because optimists have more frequent positive thoughts about themselves, the situations they are in, and the future, their brains pay more attention to positive elements in the environment and filter out information that doesn’t fit their brighter mindset. Pessimists are equally affected by attentional bias, but the information they receive isn’t filtered through rose-colored glasses. Pessimists pay more attention to negative cues while ignoring positive ones.

This has been measured in several ways, most successfully by tracking people’s eye movements when they are presented with pleasant or unpleasant images.[19] When presented with two parallel images, one pleasant, such as a smiling face, and the other unpleasant, such as a fearful face, optimists stare much less at the unpleasant image and focus much more on the pleasant image than pessimists.

As we saw at the beginning of this chapter, these types of attentional biases can be corrected with effort. One way to modify the right-brain negativity bias is to engage in visualization exercises that attribute a happy outcome to a destructive situation. [20] In one of our studies, we asked volunteers to look at pictures of fatal car accidents, quadriplegics in motorized wheelchairs, and homeless people on the street. Participants who initially scored as highly pessimistic were told what had actually happened and then asked to imagine a different, positive outcome to the scenario. For example, they might imagine the homeless person finding a winning lottery ticket on the street or the quadriplegic meeting a doctor with a magic cure. They repeated this task once a day for eight weeks. After the study period, their pessimism decreased significantly. There was significantly less activity on the right side of the frontal regions of the brain at rest, they focused less on negative information and scored higher on optimism questionnaires.

Another approach to correcting the right-brain negativity bias is to train the brain to look for positive cues in the environment. In one study, we asked research participants who scored high on pessimism to look for a single happy face in a crowd of unhappy/neutral faces displayed on a computer screen. Each session consisted of twenty visual search tasks that required finding a happy face in a crowd of unhappy/neutral faces. Our volunteers were asked to repeat the task once a day for eight weeks. Those who complied with the task scored significantly higher on measures of optimism after the eight weeks than at the starting point.

Screenshots from a task that asks participants who scored high on pessimism to identify a happy face in a crowd of neurotic faces.

This type of task doesn’t require a lab setting or the right kind of computer-based stimuli. You can complete it while sitting in a busy dentist’s office, walking through a grocery store, or riding the subway. Just practice finding the happiest face in a crowd. It turns out it’s harder than you might think. Most people are more attuned to Charlie Brown from Peanuts than Olaf the Snowman from Frozen.

Optimism in and of itself doesn’t lead to extroversion, though it’s a step in the right direction. The other trait is a tendency to be stimulated by social events like small talk with strangers, dancing at big clubs, big weddings, and corporate holiday parties. It may seem like a lot of people have this trait, and a lot of people do. But true introverts don’t have it. True introverts may tolerate these activities, and they may find them somewhat entertaining. But what excites them are the activities they do alone, away from people, curled up on a couch or chair.

Changing this trait may not be in everyone’s best interest, but there are ways to become more outward-oriented. We sometimes say that people who remember only what matters to them have selective memory. As it turns out, we all have selective memory. And that’s a good thing. As psychologist and philosopher William James noted, “If we remembered everything, we should be as ill as if we remembered nothing.” [21] We’re all pretty good at “forgetting” information that’s irrelevant to a given task or has little future value. But we don’t all consider the same information to be irrelevant or lacking future value. Often without conscious thought, introverts don’t consider their external environment to provide them with much relevant information or of future value to them. They find other people exhausting. Extroverts, on the other hand, find it maddening. They are not misanthropes, rude, or narcissists; their brains have simply hardwired this type of attentional bias as a result of genetic makeup, brain maturation, or life experience.

Interpersonal interest can be understood as a set of tendencies that cause us to like, dislike, or prefer certain things and that lead to fixed patterns of behavior.[22] If you like to talk, you will tend to seek out situations that allow you to do so, such as social gatherings. If you like to think about deep questions, such as the meaning of life, you might decide to become a philosopher. Although extroverts tend to be agreeable, openness—along with extraversion and conscientiousness—stands in sharp opposition to neuroticism and agreeableness in their strong association with interest.[23] Openness is strongly associated with interests in social affairs and adventure, while people who are merely agreeable but not open do not.

Our interests and preferences change dramatically as we go through life. Most of these changes protect us from disappointment. Unconscious influences change our preferences in light of the choices available to us. [24] For example, if you prefer a life of excess but are unlikely to have the means to do so, your brain may secretly change your preferences and make you prefer what is available. It would be nice if our brains were always making us change our preferences to suit our choices without us having to rely on conscious will or effort. But that’s not the case. If that were the case, none of us would want to become more talkative or assertive to fit into the families we were born into or the jobs we hold. Unfortunately, we haven’t yet found any really good ways to change your interests. Part of the reason for this is that interest is partly determined by levels of the reward and motivation chemical dopamine in your brain. When your dopamine levels are out of balance, you become more attracted to external stimulation. When dopamine isn’t constantly feeding your frontal lobes (as in people with attention deficit disorder) or is too high (as in people who’ve just snorted half a gram of cocaine), you’re drawn to a lot of external stimuli. However, how your dopamine levels are determined is largely down to biology, and it’s particularly difficult to modify without medication or technology. But there is hope if you’re willing to change.

Personal interest, which is your tendency to be interested in certain topics, occupations, or activities, is different from situational interest. Situational interest is spontaneous, temporary, and triggered by the particular situation you find yourself in. You might not normally be interested in talking to people, yet you find yourself fascinated by what your classmate is saying at the annual holiday party. Educational research shows that situational interest is the main factor that can stimulate personal interest. [25] Situational interest increases when you receive new information,[26] and when the activity is at least slightly related to your interests. [27] The best thing you can do if you want to strengthen your introversion is to find a small talk expert and try to endure an hour of content-free conversation. To awaken your interest in your external environment, whether it’s other people or unfamiliar activities, go beyond small talk and start focusing on the details of your surroundings. Imagine you’re an introverted philosophy student interested in the meaning of life. At the annual holiday party, you find yourself surrounded by teachers, lawyers, and future entrepreneurs from Miami’s law school, business school, and education department. When they’re not talking about work, which you can’t understand, they’re talking about the weather, which in Miami is almost unchanged. It goes on for an hour, then you can’t breathe and you collapse.

This is the wrong approach if you’re hoping for change. Consider that you can change the subject of the conversation. It might be interesting to hear what teachers, lawyers, and future entrepreneurs have to say about the meaning of life. There might be a future study of people’s attitudes toward life waiting for you.

If your external environment doesn’t interest you, it may be partly because you need to be more perceptive. One of the big secrets of extroverts is that they pay attention to detail. Some are so distracted by details that they can’t even focus on a brief verbal exchange. They may interrupt you mid-sentence to point out the cute outfit of the baby in the stroller that just passed by. Overdo it and you’ll find yourself in the presence of someone with ADHD. This means dividing attention or shifting attention to extremes. While it’s undesirable, a healthy amount of attention to detail can help stimulate interest. Since you’re reading this book, you probably have some interest in personality. Why not treat your next big social gathering as an exercise in people identification? This will leave you with a goal as well as a set of questions to ask: “Do you enjoy meeting new people?” “Are you willing to tell people off when they’re wrong?” “Do you prefer to follow the same routine every day?” “Do you try to respond to your emails as quickly as possible?” “As a parent, would you rather see your child grow up to be cute than smart?” “Are you more a natural improviser than a meticulous planner?” “If you run a business, do you find it hard to fire loyal but underperforming employees?”

The Neurotic Extrovert and the Emotionally Stable Introvert

As Susan Cain argues in her book Quiet: The Power of Introverts in a World That Can’t Stop Talking, extroverts dominate public life. They are overrepresented among politicians, lawyers, corporate leaders, and senior public administrators. It’s a trait that has become idealized in Western society. Extroverts hire other extroverts into leadership positions. This may all be a mistake. The world would be a calmer, more rational, and more peaceful place if introverts were in charge. But they are not. To live up to the extrovert ideal and succeed in the world as it is, you have two choices: either pretend, which may help you climb the career ladder under pretenses, or move across the personality spectrum to get closer to the extrovert ideal so that the world opens its eyes and recognizes the virtues of the contemplative.

Pretending, unless used systematically, which we will discuss in a later chapter, is exhausting. Change is possible because there is no need to move from one extreme to the other to stay in extrovert land.

Some aspects of extroversion are incredibly annoying and independently desirable: their optimistic attitude toward life, their ability to enjoy the most trivial routines, and their unstoppable cheerfulness. However, these aspects of extroversion are not optional; They directly relate to your life expectancy, your quality of life, and your success in your relationships.

The good news is that you can change if you’re willing to keep up with society’s trends. To increase your optimism, you can regularly look for positive things in your daily environment. Look for a happy person on the subway or a happy person at the grocery store. This has been shown to increase your optimism, and thus, in part, your openness and your ability to thrive in our open-minded society. But optimism isn’t all it takes to become an extrovert. Your interests should be outward-facing. Sure, read your novel at home while you’re curled up on your couch with a nice cup of green tea. But when you’re out and about, try to become interested in what’s around you, what people are offering, and what things are like. Ask questions—not casual conversational questions—but substantive ones. It’s been scientifically proven that looking for happy faces and other positive elements in your environment and looking for things that might interest you can make a real difference in key aspects of openness. It can help you change, too.