Habits of a Happy Brain Read online

  And now let’s meet those happy chemicals in more detail.

  2 | MEET YOUR HAPPY CHEMICALS

  You’re Unique . . . but You’re Human

  Your feelings are unique, but the chemicals that cause your feelings are the same as everyone else’s.

  Your life experience is unique, but it overlaps with everyone’s because the same basic survival needs command your brain’s attention.

  You may say you’re not focused on your “survival,” and you may not be, consciously. Loftier goals such as world peace and social justice get your attention when you talk to yourself in words. But your happy chemicals respond to your mammalian survival prospects as your brain has learned to define them.

  Meet Your Dopamine

  Dopamine promotes survival by telling your body where to invest its energy. Your ancestors foraged for food by walking slowly until something triggered their excitement. That dopamine told them when to go for it. The mammal brain scans constantly for potential rewards, and dopamine is the signal that it has found some. It feels good, which motivates you to keep seeking and finding.

  It’s important to understand foraging to understand your brain. Our ancestors didn’t know where their next meal was coming from. They constantly scanned their surroundings for something that looked good, and then invested energy in pursuit. Dopamine is at the core of this process. In today’s world, you don’t need to forage for food, but dopamine makes you feel good when you scan your world, find evidence of something that felt good before, and go for it. You are constantly deciding what is worth your effort and when it’s better to conserve your effort. Your dopamine circuits guide that decision. You might wish the good feeling of dopamine just flowed all the time, but that wouldn’t really benefit you.

  When Do You Feel Dopamine?

  A marathon runner gets a surge of dopamine when she sees the finish line. A football player is fueled by dopamine when he scores and does a victory dance. “I did it!” the brain tells the body. It feels so good that you look for ways to trigger that feeling again.

  Of course, dopamine didn’t evolve for crossing arbitrary lines on the ground. It evolved to release energy when you have a chance to meet a survival need. An ape climbing to a piece of fruit enjoys dopamine as she nears the reward. Dopamine releases her reserve tank of energy so she’s able to meet her needs. She doesn’t say “I did it!” in words, but neurochemicals create that feeling without words.

  An ape’s dopamine starts flowing as soon as she sees a fruit she can reach. That’s because her brain built a dopamine pathway when she first tasted fruit. The sugar triggered the message “this meets your needs! Get more of it!” That dopamine surge connected all the neurons active at that moment, which wired her dopamine to turn on when she sees anything similar in the future.

  How You Built Dopamine Circuits

  Your dopamine circuits are built from your own past dopamine experiences. Imagine a child foraging with his mother. He sees her excitement when they stumble on a delicious berry patch. His mirror neurons (which mirror the behavior of others, as we’ll learn more about in Chapter 3) get his dopamine flowing before he ever eats a berry. When he has his first taste, flavors rare in nature get his attention. More dopamine is triggered, which paves a pathway to the neurons active at that moment. That will help him recognize sights, sounds, and smells associated with berries in the future.

  Without effort or intent, dopamine builds a neural template that helps you find rewards. It also stimulates the energy you need to pursue rewards. We are not born with circuits defining the rewards that meet our needs. We build them from life experience. That’s why one person gets excited about eating crickets while another person gets excited about the Food Network. You can meet your needs by foraging for a career opportunity rather than a berry patch. But you do it with the operating system that met survival needs before there was language.

  Dopamine’s Ups and Downs

  You may not have a “Wow!” feeling about berries, because sweetness is no longer a rare taste. Your brain saves your energy for rewards that are scarce in your life experience. I get a rush of excitement when I see the first cherries of the season, but my excitement doesn’t last. Looking at cherries can’t make me happy all the time. My brain saves its dopamine for things relevant to my present needs instead of wasting it on things already available.

  Social rewards are not easily available because they can’t be mass produced like berries and sugar. Seeking and finding social rewards stimulates the excitement of dopamine. People invest years of effort trying to become a heart surgeon or a rock star because each step along the way triggers dopamine. Even if your goal is committing the perfect crime or living on the beach, your brain releases dopamine as you seek and find steps that bring you closer. The social rewards that stimulate your dopamine depend on your unique life experience. But we all live with the fact that dopamine is soon metabolized and you have to approach a reward again to get more.

  Research on Dopamine

  The fleetingness of dopamine was illuminated by a landmark monkey study. The animals were trained to do a task and get rewarded with spinach. After a few days, they were rewarded with squirts of juice instead of spinach. This was a bigger reward than they expected and the monkeys’ dopamine soared. But as the experimenters continued rewarding with juice, the monkeys’ dopamine declined to nothing in a few days. Their brains stopped reacting to the sweet, juicy reward. In human terms, they took it for granted. Dopamine evolved to store new information about rewards. When there’s no new information, there’s no need for dopamine.

  This experiment has a dramatic finale. The experimenters switched back to spinach, and the monkeys reacted with fits of rage. They screamed and threw the spinach back at the researchers. The monkeys had learned to expect juice. It no longer made them happy, but losing it made them mad.

  THE CONNECTION BETWEEN COCAINE AND DOPAMINE

  Cocaine stimulates more dopamine than real life. It gives you the thrill of finding berries or finishing a marathon without leaving the couch. You get the excitement of accomplishment without having to accomplish anything. Natural rewards feel less exciting if your brain learns to expect an artificial jolt.

  Such research improves our understanding of dopamine significantly over initial research conducted in the 1950s. You have probably heard about the rat wired up to electrically stimulate its “pleasure center” by pressing a lever. The rat seized the day, pressing constantly until it dropped dead. It would not stop for food or water or attractive mates. Scientists presumed the electrode was triggering pleasure. But why would a brain define pleasure in a way that motivated it to die rather than eat, drink, or mate? Now we realize that the expectation of reward triggers dopamine. The unfortunate rat kept expecting rewards from the lever because it triggered more dopamine than real-world rewards.

  Dopamine and Survival

  A small potential reward triggers a small surge of dopamine; a huge potential reward triggers a huge surge of dopamine. For example, mothers have been seen lifting a car when their child is pinned underneath. Saving your child’s life is the biggest reward there is from the perspective of your genes. A mother is not consciously thinking of her genes when she risks her life to save her child; she’s not thinking at all. Such mothers report they had no idea what they were doing. The verbal part of the brain is not needed for a dopamine circuit to unleash the energy needed for the job.

  The link between dopamine and survival is not always obvious, however. For example, computer games stimulate dopamine, even though they don’t meet real needs. Computer games reward you with points that your mind has linked to social rewards. To get the points, you activate the seek-and-find mechanism that evolved for foraging. You keep enjoying dopamine as you keep approaching rewards. The dopamine paves a pathway that tells you to expect good feelings from computer games. The next time you feel bad, the game is one way your brain knows to relieve those bad feelings. From your mammal brain’s perspective, it
relieves the threat, though the social rewards may prove more elusive.

  EXERCISE: WHEN DO YOU FEEL DOPAMINE?

  Dopamine is the excitement you feel when you expect a reward. A hungry lion expects a reward when she sees an isolated gazelle. A thirsty elephant expects a reward when he sees signs of a water hole. Dopamine unleashes your reserve tank of energy when you see a way to meet a need. Even when you’re just sitting still, dopamine motivates you to scan a lot of detail to find a pattern that’s somehow relevant to your needs. When you find details that are “just right,” it feels good. Finding the puzzle piece you’re looking for feels good because of dopamine.

  Whatever triggered your dopamine when you were young paved neural pathways that tell your dopamine when to turn on today. These circuits work without words, so your dopamine can be hard to make sense of. You will learn if you pay close attention to patterns in your excitement. Sometimes this is easier to see in others (though they may not appreciate your observations). Spend time noticing the joy of finding what you seek:

  In your work

  In your free time

  In someone else

  In surprise rewards you weren’t looking for

  The Quest for “More”

  The urge for more did not start with “our society.” In fact, our ancestors never stopped seeking either. When their bellies were full, they looked for new ways to meet their needs by making better arrows and stronger shelters. We know how hard they searched for the right materials because archaeological sites often contain materials from far away. Dopamine made the quest feel good, but the feeling soon passed and they kept seeking more. Every brain learns to link effort and reward, whether material rewards, social rewards, or relief from a threat.

  If you are studying for a math test, you are fueled by dopamine. You may not consciously think it feels good, but something in your life connected math to other rewards. It could be material rewards, social rewards, or just the good feeling of an achievement. Solving math problems is another kind of seek-and-find activity. When you find the right answer, you get that “I did it!” feeling, which erases any cortisol feelings for a moment. When your answer is wrong, you may try again because you still expect a reward.

  An athlete spends long hours training because a little dopamine is stimulated by each step toward expected rewards. Winning games or medals triggers a big burst of dopamine, but these are only steps as well. An athlete has linked these steps to rewards that feel relevant to survival, be it material rewards, social rewards, or internal rewards.

  Each brain has built expectations about survival rewards and the steps it takes to reach them. When you moved toward your expected reward, dopamine makes it feel good.

  Meet Your Endorphin

  “Euphoria” is a common description of the endorphin feeling. But this neurochemical did not evolve for good times. Physical pain is what triggers it. You may have taken a bad fall and got up thinking you were fine, only to discover that you’re seriously injured. That’s the power of endorphin.

  Endorphin masks pain for a short time, which promotes survival by giving an injured mammal a chance to reach safety. If your ancestor broke his leg while hunting, or got worn down by hunger and thirst, the oblivion of endorphin helped him do what it took to save himself.

  “Runner’s high” is a well-known endorphin experience. But you cannot get a daily high from a daily run. Endorphin is only released if you push past your capacity to the point of distress. This is not necessarily a good way to promote survival. Endorphin did not evolve to motivate self-inflicted pain. It evolved to escape pain.

  Perhaps you’ve seen a zebra wriggle out of the jaws of a lion on a wildlife documentary. You see the zebra’s flesh ripped open but it can still run. Endorphin masks the pain for a few moments, which helps the zebra escape. If it fails to escape and ends up in the lion’s jaw, it will at least die in an endorphin haze. It’s nice to know about nature’s morphine when you see disturbing footage. It reminds you that endorphin exists not for partying but for momentary respite in the struggle for life.

  Pain Does Have Value

  The respite of endorphin is brief because pain has survival value. Pain is your body’s signal that something is urgently wrong. If you ignored pain all the time, you would touch hot stoves and walk on broken legs. You would not make good survival choices if you were always high on endorphin. We evolved to notice distress signals, not to keep masking them with oblivion.

  When endorphin was discovered, it was called endogenous morphine because it was so similar to opiates yet was produced by the body’s own endogenous systems. But it would be more true to say that morphine is the drug industry’s endorphin. Heroin and other opium derivatives have an effect on us because they fit our natural endorphin receptors.

  We are not designed to release endorphin all the time. Exercise can give you a little, but exercising to the point of pain doesn’t promote survival. Laughing and crying trigger internal convulsions that stimulate endorphin, but this road to euphoria is limited too. Fake laughs don’t trigger the internal convulsions, and real laughs only last for seconds. Real cries are painful, and fake cries don’t trigger the physical distress.

  A broken heart doesn’t trigger endorphin the way a broken bone does. Endorphin did not evolve to mask social pain. In the past, daily life held so much physical pain that social pain was secondary. Today, we suffer less from the pain of manual labor, predator attack, foraging accidents, and deteriorating disease. We have more energy to focus on painful social disappointments. This leaves us feeling that life is more painful even as it’s less painful.

  EXERCISE: WHEN DO YOU FEEL ENDORPHIN?

  Endorphin is an oblivious feeling that masks physical pain. Endorphin allows an injured animal to escape from a predator and save its life. We are designed for survival, not for getting high. Nature’s opiate is only released in short spurts because pain is actually good for you: it tells you not to touch fire or run on a broken leg. Exercise is good, but “runner’s high” only happens if you exercise to the point of pain. We are not designed to inflict pain on ourselves to feel good. Fortunately, small drips of endorphin are stimulated by laughing, crying, and reasonable exertion. You can’t expect a constant high, but you can celebrate your body’s ability to manage pain. Notice your endorphin at work in a moment when:

  You were hurt but didn’t realize it for a few minutes

  You felt good after a big physical exertion

  You felt good after a belly laugh

  You felt good after a real cry

  Adrenaline Is Not the Same As Endorphin

  Endorphin is different from adrenaline. Skydiving and bungee jumping trigger an “adrenaline high.” You anticipate pain and your body releases adrenaline to handle the emergency. The “adrenaline junkie” is not seeking pain, but the rush of energy designed to avoid pain. When you see the ground rushing at you, your brain anticipates pain, even if you’re safely attached to a rope or a roller coaster. Your brain evolved in a world of real threats, not self-imposed, artificially concocted threats.

  Adrenaline is outside the scope of this book because it does not cause happiness. It causes a state of arousal, as if your body is stepping on the gas. Some people learn to like that feeling, but it is not a signal that something is good for you. It is a signal that something is extremely relevant to survival, whether good or bad, and thus requires your energy. For example, if you are about to accept the Nobel Prize from the king of Sweden, a spurt of adrenaline tells you that the moment is important and provides the energy to manage it. If your parachute doesn’t open, that is important too. Adrenaline amplifies the positive or negative message conveyed by the other neurochemicals. It prepares you for immediate action, but it doesn’t tell you whether that action should be going toward or running away.

  Meet Your Oxytocin

  When you feel like you can lean on someone, oxytocin creates that feeling. When you trust someone, or enjoy someone’s trust in you, oxytocin is flowi
ng. The pleasure of belonging or safety in numbers is oxytocin too.

  The Connection Between Oxytocin and Trust

  Social trust promotes survival, so the brain rewards it with a good feeling. But trusting everyone is not good for survival. That’s why your brain evolved to analyze social alliances instead of just releasing oxytocin all the time.

  Feeding a horse is a simple example of the oxytocin feeling. When I walk toward a horse with food in my hand, we check each other out. The horse fears strangers but wants the food. I fear putting my hand into those huge teeth but I want to enjoy the shared trust. Each of us scans for evidence that it’s safe to trust. When both of us are satisfied that the other doesn’t pose an immediate threat, we relax, and it feels good. That’s the release of oxytocin.

  Horses survive by trusting their herd mates. A herd is an extended alarm system. Each horse shares the burden of staying alert for predators. The horse that trusts its fellow horses can relax a bit and still survive.