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February 6 - February 19, 2023
In short, your brain has some quirks: It cares for the survival of your genes as urgently as it cares for your body. It wires itself from early experience, though that’s an imperfect guide to adult survival.
Dopamine produces the joy of finding things that meet your needs—the “Eureka! I got it!” feeling. Endorphin produces oblivion that masks pain—often called euphoria. Oxytocin produces the feeling of being safe with others—now called bonding. Serotonin produces the feeling of being respected by others—pride.
Modern society is not the cause of vicious cycles. Our ancestors had variations of their own. For example, they made human sacrifices to relieve threatened feelings, and when they felt bad again, they made more sacrifices.
Dopamine is the brain’s signal that a need is about to be met.
For humans, finding “the One” makes you high on dopamine. However you define what you seek, dopamine excites you when you approach it.
Friendship bonds stimulate oxytocin, and they also promote reproductive success. Monkeys and apes with more social alliances have more surviving offspring,
when you receive the affection of someone you perceive as important, your serotonin surges.
Endorphin is stimulated by physical pain, but you get a bit from laughing and crying too.
Cortisol plays an important role in reproductive success, too. It makes you feel bad when you lose love, which promotes survival by helping you move on. If you remained attached to a person who is not available to you, your genes would be doomed. Cortisol helps your brain rewire to associate your old lover with negative rather than positive expectations, so you start seeking love elsewhere. We wish lost love wouldn’t feel so bad, but it’s interesting to know that the bad feeling has a valuable function.
There is no free love in nature. Every species has preliminary qualifying events before mating. Creatures work hard for any mating opportunity that comes their way.
Something as small as failing to get a smile from the person you smile at can trigger surprising neurochemistry because your brain relates it to the survival prospects of your genes.
Today, we explore many ways to trigger happy chemicals, but you must keep working to keep them coming. Each burst of a happy chemical is metabolized in a short time so you’re always looking for ways to get more. Maybe that’s why love songs are always popular. They stimulate brain chemicals without the messy side effects.
The monkeys had learned to expect juice. It no longer made them happy, but losing it made them mad.
Dopamine is the excitement you feel when you expect a reward.
Endorphin masks pain for a short time, which promotes survival by giving an injured mammal a chance to reach safety.
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.
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.
Social alliances can entangle you in trouble, but oxytocin makes it feel good.
Reptiles have no warm and fuzzy feelings toward other reptiles.
Reptiles strike out on their own the moment they’re born. Instead of relying on parental care, a young lizard starts running the instant she hatches from her shell. If she doesn’t run fast enough, a parent eats her—the better to recycle the energy into another sibling instead of letting a predator get it.
Parental attachment revolutionized the biology of the brain. It became possible for mammals to be born without survival skills and to learn from life experience instead. Unlike reptiles, fish, and plants, which are born with all necessary survival knowledge, mammals are born fragile and stupid. The mammal brain does not fully develop in the safety of the uterus or egg. It develops by interacting with the world around it.
Today, lasting attachments are less preferred and often disparaged. Without them, however, we feel like something is wrong. We don’t know why, but we long for the place where “everybody knows your name.” Or the crowded sports arena or concert hall where thousands of people act on the same impulse. Or the political group that shares your anger. Or the online forum that welcomes your comments. These things feel good because social alliances stimulate oxytocin.
In mammals, serotonin is the good feeling of having secure access to food or other resources.
The piglet’s cortisol spikes if it’s seriously underfed. That motivates aggression, which helps it get food. Aggression is different from social dominance, because cortisol feels bad while serotonin feels good. Social dominance is the calm, secure expectation that you will get what you need. Cortisol is the sense that something awful will happen if you don’t act now.
The point is that your brain constantly monitors your access to resources. When access looks secure, you feel good for a moment, and then you look for ways to make it more secure. You may get annoyed when you see others trying to secure their position. But when you do it, you think, “I’m just trying to survive.
Your brain is always looking for ways to enjoy serotonin without losing oxytocin or increasing cortisol. For example, if your comment in a meeting gets respect, that feels good. But if you dominate the meeting, you may end up with pain. Each experience of pain or pleasure builds connections that help you figure out how to feel good and survive.
Social dominance is different from socioeconomic status. A person who is number 3 on the world billionaire list might feel like his survival is threatened when he falls to number 4. By contrast, a person with little socioeconomic status might harshly dominate those around him and feel good about it.
The human brain stem and cerebellum are eerily similar to a reptile’s brain.
Your reptile brain lies where these higher layers and your body intersect, so it’s not surprising that you find patterns in the social world that give your body a threatened feeling.
Cortisol creates the belief that life is worse today.
When you worry about the SATs or looking fat, cortisol creates the physical sense of imminent annihilation.
Animals with bigger brains have bigger social ups and downs. Small-brained mammals tend to size each other up once and build a lasting circuit. Primates have enough neurons to keep updating their feelings about each other.
We do not mirror everything we see in others. Mirror neurons only fire when you watch someone get a reward or face a threat. The firing is much weaker than executing an action yourself. But if you repeatedly watch another person get a reward or face a threat, connections build. You wire yourself to get the reward or avoid the threat in the way that you’ve seen. This research is in its infancy, but it has been learned that songbirds have mirror neurons, and they learn their songs by listening to others.
Mirror neurons allow us to feel other people’s pain. This has a benefit, as often suggested by empathy researchers, but it also has a cost. You can get wired to suffer just by being around people who suffer. Even if your life is fine, mirroring builds a pathway to your cortisol. Once your physical sense of threat is turned on, your cortex looks for evidence of threat. It will find evidence because that eases the “do something” feeling.
It may feel like something is wrong with the world when childhood ends and you face threats for yourself. Yet this is the way of nature. No species could survive unless its young learned survival skills before its parents died. Cortisol surges when you face threats without the protection of your elders. So every brain wires itself with the pain of losing social support.
Exclusion makes you unhappy, but inclusion does not necessarily make you happy. Once you’re in a group, you see others getting what you are not getting. You feel bad, though you hate to admit it. There’s a good physical reason for this pervasive source of unhappiness. The first experience in your brain, the circuit at the foundation of your neural network, is the sense that you will die if you don’t get attention.
Your early vulnerability circuits are still there. When your poetry is ignored by the one you love, or your views are ignored at a meeting, these circuits send electricity to your cortisol. We don’t consciously think it’s a matter of life and death to be seen and heard, but old circuits make it feel that way.
You may say you don’t care about status, but when a high-status person notices you, your happy chemicals soar. Raising your children’s status thrills your mammal brain even more. When your specialness is overlooked, your unhappy chemicals spike, and if your children’s specialness is overlooked, it’s much worse.
The urge for specialness might seem annoying in others, but in yourself, it just feels like fairness.
We seek evidence of threats to feel safe, and we get a dopamine boost when we find what we seek. You can also get a serotonin boost from the feeling of being right, and an oxytocin boost from bonding with those who sense the same threat. This is why people seem oddly pleased to find evidence of doom and gloom.
Knowing the world will go on without you someday is more distressing than we realize. It’s so upsetting that you’re tempted to imagine the world ending when you end. Then you won’t be missing anything.
Your cortex promotes survival by looking for logical explanations of what your mammal brain feels is true. If you feel that things are falling apart, for example, you will find evidence that things are falling apart and overlook evidence of things going well.
You may feel sure that you’re focused on facts and couldn’t possibly be so biased. But your brain actually has ten times more neurons telling your eyes what to look for than it has to take things in randomly. That is, ten times more neurons send information from the cortex to the eyes than from the eyes to the cortex. We are designed to scan for inputs we’ve already experienced as important rather than wasting our attention on whatever comes along.
A clear example is the way your cortex reads this page. It does not just take in details passively. It generates expectations about the chunk of detail that will come next, based on past experience. Dopamine is released when you see a chunk that matches your expectations. You extract meaning and move on to generate an expectation about the next chunk. If a chunk fails to match your expectations, cortisol is released, which prompts you to take a closer look before you create meaning and move on. You’re not conscious of generating expectations before you read a word, but you’d never be able to
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Your cortex is always making predictions about future pain and future rewards. But anticipated rewards don’t always materialize, which is another source of cortisol. Your cortex can imagine a better world that makes you happy all the time, but you fail to find this utopia. Reality is often a disappointment, and it’s hard to understand the role of your expectations because your cortex generates them so effortlessly.
A lizard never thinks something is wrong with the world, even as it watches its young get eaten alive. It doesn’t tell itself “something is wrong with the world,” because it doesn’t have enough neurons to imagine the world being other than what it is. It doesn’t expect a world in which there are no predators, so it doesn’t condemn the world for falling short of expectations. It doesn’t condemn itself for failing to keep its offspring alive. Humans expect more, and we do something about it. That’s why we end up focused on our disappointments instead of saluting our accomplishments.
Expectations are neural pathways that you electrically activate in anticipation of incoming information.
But reptiles don’t fault themselves for excessive caution. False positives are part of the reptilian survival system. We humans hate false positives. We want to duck bullets, but we don’t want to duck when there’s no bullet. We expect our alarm system to call the shots perfectly every time.
When I wish my cortisol would stop, I think about feral pigs. (These are pigs that have escaped from farms and returned to the wild.) They fascinate me because feral pigs start developing the features of wild boars once they start meeting their own survival needs. Their snouts grow bigger when they use those snouts to root for food. Their fur grows longer when they need it for shelter from the cold. In short: the bad feeling of hunger and cold triggers the strengths the pigs were meant to have. You can trigger the strengths you were meant to have when you understand your threat responses.
experienced the brain’s indifference to old information in a local flower shop. I was thrilled by a fabulous smell when I walked in the door, and decided to buy a bouquet so I could keep enjoying it. After I paid for the bouquet, I took one last deep breath before heading to my car. I was surprised to find that I hardly smelled anything! It was not new information.
Wow her brain works quick! My happy chemicals seem to last longer than she describes and my brain doesn't grow indifferent as quickly as she describes.
