Brains make more than one kind of mind

When people from the island of Bali in Indonesia are afraid, they fall asleep. Or at least, that's what they're supposed to do.

Falling asleep might seem like a strange thing to do when you're afraid. If you're from a Western culture, you're supposed to freeze on the spot, widen your eyes, and gasp. You can also squeeze your eyes shut and scream, like a teenage babysitter in a bad horror movie. Or you can run away from whatever is scaring you. These behaviors are Western stereotypes for proper fear behavior. In Bali, the stereotype is to fall asleep.

What kind of mind snoozes out of fear? A kind of mind that's different from yours.

Human brains make many different kinds of minds. I don't just mean that your mind is different from your friends' and neighbors'. I'm talking about minds that have different basic features. For example, if you are from a Western culture, like I am, your mind has features called thoughts and emotions, and the two feel fundamentally different from each other. But people who grow up in Balinese culture, as well as in the Ilongot culture in the Philippines, do not experience what we Westerners call cognition and emotion as different kinds of events. They experience what we would call a blend of thinking and feeling, but to them it's a single thing. If you find this kind of mental feature hard to imagine, that's okay. You don't have a Balinese kind of mind.

As another example, Western minds often try to guess what other people are thinking or feeling. This mental inference is such a basic and valuable skill in our culture that when we encounter people who are not so good at it, we may see them as abnormal instead of merely different. But in some other cultures, attempts to peer into another person's mind are considered unnecessary. The Himba people of Namibia often figure each other out by observing each other's behavior, not by inferring a mental life behind that behavior. If you smile at another American, his brain might guess that you're happy to see him and predict that you'll say hello. If you smile at a Himba, his brain might predict only the hello (moro, in their language).

Even within a single culture, we find different kinds of minds. Think about the minds of great mathematicians who can conceive of calculations that other minds cannot. Or think about the mind of Greta Thunberg, a teenager who has sailed around the world offering tough talk about climate change. Thunberg's mind is on the autism spectrum, and she says things that others aren't willing to say. She calls her condition a "superpower" that helps her continue her mission when people criticize her efforts.

Think also about people who suffer from schizophrenia and experience severe, ongoing hallucinations. Today, people with this kind of mind are considered mentally ill, but centuries ago, they might have been called prophets or saints. Hildegard of Bingen, a twelfth-century scholar and nun, experienced visions of angels and demons and heard disembodied voices that were believed to come from God.

This variation in mind types should not, at this point in our lessons, come as a surprise. [In previous chapters] We have learned that humankind has a single brain architecture — a complex network — and yet each individual brain tunes and prunes itself to its surroundings. We've also learned that the mind and the body are strongly linked, and the boundary between the two is porous. Your brain's predictions prepare your body for action and then contribute to what you sense and think and feel.

In short, a particular human brain in a particular human body, raised and wired in a particular culture, will produce a particular kind of mind. There is not one human nature but many. A mind is something that emerges from a transaction between your brain and your body while they are surrounded by other brains-in-bodies that are immerse in a physical world and constructing a social world.

Let me be clear here. I'm not saying the human mind is a blank slate and each of us becomes whatever the environment tells us to be, like there's nothing innate. That's the sort of mind that might emerge from Meatloaf Brain, the imaginary brain structure from lesson no. 2, in which every neuron is connected to every other. I'm also not saying people come into the world with their brains fully realized so that there's a single, universal human nature. That's the sort of mind that might emerge from Pocketknife Brain, the other imaginary brain structure, which consists of distinct brain regions, each with a dedicated function. I'm describing a third possibility. We come into the world with a complex brain structure that can be wired in a variety of ways to construct different kinds of minds.

It's important for humans to have many kinds of minds, because variation is critical for the survival of a species. One of Charles Darwin's greatest insights was that variation is a prerequisite for natural selection to work. Think about it: If there's a huge change in the environment, like a catastrophic drop in the food supply or a big increase in temperature, a species without much variation might be completely wiped out. A species with great variation will more likely have some survivors after any catastrophe — the members who are well suited for the new environment. Darwin observed variation in the bodies of animals, and the same principle applies to human minds. If we all had the same kind of mind — if there were only one human nature — then when disaster struck, we might become extinct. Thankfully, our species has many kinds of minds, both within a single culture and across cultures, so we're less likely to be wiped out. This variation preserves the evolvability of our species.

Even though variation is the norm — and a blessing for our species — it makes people uneasy. The idea of a single, universal human nature is so much more comfortable than continuous variation. So even when scientists do acknowledge that there are different kinds of minds, they try to tame the variation by organizing it into categories. They sort people into neat little boxes with labels. Some people are labeled as having a warm personality, and others are cold. Some people are more dominant and others more nurturing. Some cultures prioritize individuals over the group, while others do the opposite. Each box represents a feature of the mind that seems universal, and scientists use the boxes to catalog human minds.

You may have seen personality tests that collect information about you and assign you to a little box. A great example is the Myers-Briggs Type Indicator, or MBTI, which sorts people into sixteen little boxes labeled with different personality types to classify you and supposedly help you get ahead in your career. Sadly, the MBTI's scientific validity is pretty dubious. This test and its many cousins typically work by asking what you believe about yourself, which research suggests may have little to do with your actual behavior in daily life. Personally, I prefer the Hogwarts Sorting Test, which has only four boxes and is far more rigorous. (I'm a Ravenclaw.)

Scientists also try to organize the variation of minds by classifying what's normal and what's not. The problem is that "normal" is relative. For example, homosexuality was listed as a psychological illness for many years in the official catalog of mental disorders maintained by the American Psychiatric Association. Today, many people acknowledge a wide range of sexual orientations, identities, and genders as normal variation. (We're still cramming the variation into lots of little boxes, but it's a start.)

All of this organizing and labeling is an attempt to identify features of the mind that are universal across our species. It seems like common sense that if you and I are part of the same species, along with a farmer in Buenos Aires, a shopkeeper in Tokyo, and a Himba goat-herder in Namibia, then all of these minds should be similar in certain ways. Some scientists even go looking for circuits in the brain that might house each so-called universal feature. And if they find a similar circuit in a nonhuman animal brain, they conclude that the animal has that psychological feature as well, and the world suddenly feels a bit cozier, like we've taken a step toward understanding evolved human nature.

But if there's one thing that's clear from our earlier lessons, it's that common sense isn't much use when it comes to understanding how a brain works. Brains have a lot of common features; minds, less so, because minds depend in part on micro-wiring that is tuned and prunedby culture. For example, many Western cultures draw strong dividing lines between the mental and the physical. If your stomach hurts, you're likely to visit your primary care physician or a gastroenterologist; if you're feeling anxiety, you're more likely to see a psychologist, even if the symptoms and the underlying pathology are identical. But in some Eastern cultures, such as those that practice Buddhism, mind and body are much more integrated.

As far as I can tell, the human mind has no universal defining features. Pick any mental feature that's unique to humans, such as rich, spoken language, and you can always find some humans who don't have it, such as newborn infants. Alternatively, pick any mental feature that virtually all humans have, such as cooperation, and you can find plenty of other animals that have it too.

Even so, we can still find mental features that are widespread — because they're really, really useful, even if they aren't universal. One example is the ability to have relationships.

It's useful to have a mind that defines itself in relation to others, particularly if your culture values the group over the individual. It's also useful to have a mind that separates itself from others, especially if your culture values the individual over the group. But people who care about neither themselves nor anyone else will have a hard time functioning in any human culture.

An especially useful feature of the mind, and one of the closest things we have to a universal mental feature, is mood — the general sense of feeling that comes from your body. Scientists call it affect. Feelings of affect range from pleasant to unpleasant, from idle to activated. Affect is not emotion; your brain produces affect all the time, whether you're emotional or not and whether you notice it or not.

Affect is the source of all your joys and sorrows. It makes some things profound or sacred to you and other things trivial or vile. If you're a religious person, affect helps you feel connected to God. If you're a spiritual person but not necessarily religious, affect becomes the transcendent feeling of being part of something larger than yourself. If you're a skeptic, affect is what drives your certainty that others are wrong.

The elements of affect or mood

Where does affect come from? In every moment — like right now, as you read these words — your organs, hormones, and immune system are producing a storm of sense data, and you're barely aware of it. You notice your heartbeat and breathing only when they're intense or you focus on them. You almost never notice your body temperature unless it's too high or too low. Your brain, however, makes meaning from this data storm continuously to predict your body's next action and meet its metabolic needs before they arise. In the midst of all this activity inside you, something miraculous happens. Your brain summarizes what's going on with your body in the moment, and you feel that summary as affect.

Affect is like a barometer for how you're doing. Remember, your brain is constantly running a budget for your body. Affect hints at whether your body budget is in balance or in the red. Ideally, evolution would have given you something more specific, like an app or a smart watch to regulate your body budget precisely. Beep! You would hear. You're running low on glucose. Have an apple or, even better, a piece of chocolate. And by the way, you didn't sleep enough last night, so you're running low on a brain chemical called dopamine. Drink eight ounces of coffee, preferably dark roast with a little bit of cream, to borrow energy from tomorrow to get through the rest of today. Unfortunately, affect is not so precise. It just tells you, Beep! You feel like crap. Then your brain must predict what to do next to keep you alive and well.

Scientists are still puzzling out how your brain's bodybudgeting activities, which are physical, become transformed into affect, which is mental. Hundreds of studies from laboratories around the world, including mine, observe that it happens, yet this transformation from physical signals to mental feelings remains one of the great mysteries of consciousness. It also reaffirms that your body is part of your mind — not in some loose, mystical way, but in a tangible, biological way.

Even though every human culture produces minds that feel pleasure, displeasure, calmness, and agitation, we don't necessarily agree on what makes us feel these things. Some of us may find a gentle touch to be pleasant, others may find that same touch unbearable, and a few prefer a good spanking. Even here, variation is the norm. What the brain does to regulate the body may be universal, but the resulting mental experiences are not.

Your kind of mind is just one among many, and you are not stuck with the mind you have. You can modify your mind. People do this all the time. College students use caffeine or amphetamines to create minds that can pull an all-nighter before a final exam. Partygoers drink alcohol to create minds that are more relaxed and less inhibited in social situations (and miraculously, other people around them suddenly become much more attractive). These chemical modifications last for only a short time. For longer-lasting modifications, you can try new experiences or learn new things to rewire your brain, as we discussed in earlier lessons.

A particularly challenging way to modify a mind is by moving it to another culture. If you've heard the story of the country mouse and the city mouse, or read The Prince and the Pauper, by Mark Twain, or seen movies like Lost in Translation, you know how it goes. The characters are thrust into cultures so unfamiliar that they don't know how to conduct themselves.

Imagine landing in a culture where you don't know even the most basic things. What is an acceptable way to greet people or even look at them? How close can you stand to other people without being rude? What do unfamiliar hand gestures and facial movements mean? Your mind must acclimate to the new culture. Scientists call this activity acculturation, and it's like an extreme version of plasticity. You're suddenly swimming in new and ambiguous sense data, and your brain needs to tune and prune itself so it can efficiently guess what to do.

Acculturation can be really challenging. If you've ever visited a country where people drive on the opposite side of the road, you know the mental pain of acculturation firsthand. Even the simple question of what is food and what is not food can be an adventure in a new culture. Imagine sitting down to eat and seeing for the first time an entire boiled sheep's head on your plate, or a bowlful of bee larva, or a Twinkie, for God's sake. One culture's food is another culture's inedible object.

Acculturation is not always about crossing geographic boundaries. You change cultures when you switch between work life and home life, and when you change jobs and have to learn the different norms and jargon of your new workplace. Military personnel have to acculturate at least twice — when they enter the armed forces and when they return home from deployment.

Your brain constantly issues predictions to manage your body budget, and if those predictions are out of sync with your current culture, your budget may accrue a deficit, which makes it easier for you to become sick. This is particularly true for the children of immigrants. They are of two cultures — their parents' culture and their adopted culture — and have to pivot between two kinds of minds, which adds a burden to their body budgets. No kind of mind is inherently better or worse than an other. Some variations are just more tailored to their environment.

When it comes to human minds, variation is the norm, and what we call "human nature" is really many human natures. We don't need one universal mind in order to claim that we are all one species. All we need is an exceptionally complex brain that wires itself to its physical and social surroundings.

- Seven and a Half Lessons About the Brain by Lisa Feldman Barrett is published by Picador on 4 March 2021 (Hardback, £14.99)