Notes on the book "Seven and a Half Lessons About the Brain" by Lisa Feldman Barrett

Professor Lisa Feldman Barrett is a neuro-scientist and psychologist who studies the brain and especially how emotion works in the brain.

In addition to her 240 peer reviewed scientific publications, she is the author of the popular books How Emotions are Made: The Secret Life of the Brain and Seven and a Half Lessons About the Brain, the book notes on which you are reading here.

The book consists of seven and a half beautifully written and amazing stories about the human brain.

If you have any interest in how humans work, or in brains (and who doesn’t?!), and you like good stories, please purchase and read this book.

In the meantime, you can apply that amazing, ever-evolving, never-sleeping chunk of information processing tissue in your skull to ingest the concepts encoded by the words below!

Your Brain Is Not for Thinking

The main reason or motivation for the evolution of the brain was not such much the ability to think, which is admittedly an entertaining side-effect, but rather the efficient running of the body budget.

Feldman Barrett writes:

A budget for your body similarly tracks resources like water, salt, and glucose as you gain and lose them. Each action that spends resources, such as swimming or running, is like a withdrawal from your account. Actions that replenish your resources, such as eating and sleeping, are like deposits

Body budgeting, or allostatis, refers to the idea that organisms continuously and automatically predict the body’s needs before they arise.

For the human body with all of its complexity, it’s clear to see that accurately predicting needs and expenditures before they arise can become tricky, and might just require that big brain after all.

It becomes especially interesting when you remember that our complex social embedding and interactions form a crucial part of our survival.

In other words, we’re not just predicting the direct physical needs of our own bodies, but a whole network of interwoven social interactions and relationships, the effects of our actions and those of others on everyone in that network, and the possible future implications for our requirements and expenditures.

We’re going to need that supercomputer.

You Have One Brain (Not Three)

Just like it is to me, I’m sure that the idea of the triune brain, that is the idea that the humain brain consists of three “layers”, namely the most primitive “lizard” brain, focused on survival, the slightly more modern limbic system for emotion on top of that and finally the neocortex, the rational part that differentiates humans from other animals and that includes the prefrontal cortex, is quite familiar to you.

It’s clear that Feldman Barrett experiences considerable mirth when she gets to shatter that familiar mental model for everyone reading her book.

After some unravelling of assumptions, she writes:

The triune brain idea is one of the most successful and widespread errors in all of science. It’s certainly a compelling story, and at times, it captures how we feel in daily life.

[some text omitted]

But human brains don’t work that way. Bad behavior doesn’t come from ancient and unbridled inner beasts. Good behavior is not the result of rationality. And rationality and emotion are not at war . . . they do not even live in separate parts of the brain.

A bit further on, we learn that the brains of all mammals, and possibly the brains of reptiles and other vertebrates, are “built from a single manufacturing plan”.

In other words, in typical lazy (or efficient) Mother Nature fashion, maximal reuse is at play here, and we’re not special. (phew)

The brains follow the same manufacturing process, with the same stages in the same order, but the stages do run for different durations depending on the species.

To further ram that point home:

So the human brain has no new parts. The neurons in your brain can be found in the brains of other mammals and, likely, other vertebrates. This discovery undermines the evolutionary foundations of the triune brain story.

As an… erstwhile fan of pre-frontal cortex (PFC) explanations, I felt quite directly addressed by her final assertion that it was really time to let the triune brain go now:

Anything you read or hear that proclaims the human neocortex, cerebral cortex, or prefrontal cortex to be the root of rationality, or says that the frontal lobe regulates so-called emotional brain areas to keep irrational behavior in check, is simply outdated or woefully incomplete. The triune brain idea and its epic battle between emotion, instinct, and rationality is a modern myth.

The 1.5th lesson is concluded with some great advice for the future:

You have one brain, not three. To move past Plato’s ancient battle, we might need to fundamentally rethink what it means to be rational, what it means to be responsible for our actions, and perhaps even what it means to be human.

Your Brain Is a Network

(I already had some knowledge of the brain network, but this lesson surprised me with new knowledge on every page!)

Your brain is a network of 128 billion (that’s 128 thousand million, or 128 x 109) interconnected neurons.

There are very many connections…

How many?

Each neuron directly passes information to just a few thousand other neurons and receives information from a few thousand others, give or take, yielding over five hundred trillion neuron-to-neuron connections.

Five hundred trillion means five hundred million million, or 500 x 1012.

If you went and connected each neuron with every other neuron, there would be many more connections than this, but that would be far too expensive, energy-wise.

Instead, the brain is connected just well enough to do its amazing job, in a superbly energy-efficient way.

The next lesson that struck me was this:

Your brain network is always on. Your neurons never just sit around waiting for something in the outside world to make them fire. Instead, all of your neurons chat constantly with one another through their wiring. Their communications may become stronger or weaker depending on what’s happening in the world and in your body, but the conversation never stops until you die.

It’s pretty crazy to think (haha) that all of those connections are firing, all the damn time.

It never stops, until you die.

A network of clustered neurons, some clusters acting as long-distance hubs

Getting back to the observation that the brain is not fully connected, but rather sparsely so, a good next question would be “but how exactly is it sparsely connected?”.

Unsurprisingly, Feldman Barrett has a crystal clear explanation of the modular structure of the brain:

Your brain network is organized in much the same way [as the network of airports]. Its neurons are grouped into clusters that are like airports. Most of the connections in and out of a cluster are local, so, like an airport, the cluster serves mostly local traffic. In addition, some clusters serve as hubs for communication. They are densely connected to many other clusters, and some of their axons reach far across the brain and act as long-distance connections. Brain hubs, like airport hubs, make a complicated system efficient. They allow most neurons to participate globally even as they focus more locally. Hubs form the backbone of communication throughout the brain

To the best of our (where with “our”, I mean “science’s”) knowledge, this kind of network gives the most bang for your energy buck. It’s extremely powerful, yet efficient and as an added bonus actually fits into your skull.

I also found it interesting to read that damage to the hub clusters specifically was associated with a number of neurological disorders, such as depression, schizophrenia, dyslexia, chronic pain, dementia and Parkinson’s.

Just as would be the case with an airport network, if the airport hubs were damaged, that would have far-reacing effects on the whole system.

The network is bathed in chemicals called neurotransmitters

Each tiny neuron continuously fires its electrical signal out through its axon into possibly thousands of downstream neurons.

The gap between the firing axon and the receiving neuron’s dendrite is called a synapse.

To add some more variability and flexibility to the already complex network, the whole thing is bathed in neurotransmitters which either help or hinder that firing:

Your brain wiring is bathed in chemicals that complete the local connections between neurons. These chemicals, such as glutamate, serotonin, and dopamine, are called neurotransmitters, and they make it easier or harder for signals to pass across synapses.

Perhaps because that wasn’t already interesting enough, a subset of these chemicals, notably serotonin and dopamine, can boost or diminish the effect of other neurotransmitters, and can therefore be called neuromodulators.

Neurons can do different tasks, the same task can be done by different neurons

The common perception that each brain region is responsible for a specific task is incorrect. Groups of neurons are indeed more likely to perform a specific task, but there are many examples of such groups participating in various other tasks.

Similarly, the same task can easily be performed by different sets of neurons, a phenomenon called degeneracy.

Feldman Barrett notes that even reaching for the exact same thing twice in a row will engage different sets of neurons.

Slow to fast changes, complexity is key in dealing with our reality

I really liked the explanation of how the brain adapts to the world at different speeds:

  • Slow changes by learning / rewiring connections / plasticity.
  • Faster changes by neurotransmitters and neuromodulators.
  • Neurons performing multiple jobs.

The network needs to be this complex because:

… your brain can create massive numbers of different patterns by combining bits and pieces of old patterns it has made before. The result is a brain that runs its body efficiently in a world full of constantly changing situations by recalling patterns that helped in the past and generating new ones to try.

… and then further down, this intriguing observation on memories not being stored, but being reconstructed on demand:

Brains of higher complexity can remember more. A brain doesn’t store memories like files in a computer—it reconstructs them on demand with electricity and swirling chemicals. We call this process remembering but it’s really assembling. A complex brain can assemble many more memories than either Meatloaf Brain or Pocketknife Brain could. And each time you have the same memory, your brain may have assembled it with a different collection of neurons.

This lesson is wrapped up with the mind-expanding (haha) realization that the brain encompasses more than just the neurons in your head:

Your brain is more than just neurons. It includes blood vessels and various fluids that I haven’t talked about. It also includes other kinds of brain cells, called glial cells, that function in ways that scientists don’t fully understand yet. Your brain network may even extend, surprisingly, into your gut and intestines, where scientists have found microbes that communicate with your brain via neuro-transmitters.

Little Brains Wire Themselves to Their World

Please note, teenagers and other young adults, your brain is only fully formed when you reach the ripe old age of 25!

… little human brains are born under construction. They don’t take on their full adult structure and function until they finish their principal wiring, a process that takes about twenty-five years.

This has interesting and far-reaching consequences for the best approach to work with younger humans. They might walk like adults and talk like adults, when in fact they still need a few years of brain maturation before being fully responsible.

On the other hand, the record for humans older than 25 is also not that impressive.

Half-jokes aside, it is fascinating and quite terrifying to read how much a human child is, often irrevocably, formed by its environment:

To a remarkable extent, a baby’s genes are guided and regulated by the surrounding environment. The brain areas that are most centrally involved in vision, for example, develop normally after birth only if a baby’s retinas are regularly exposed to light. An infant’s brain also learns to locate sounds in the world based on the specific shape of the baby’s ear. To make matters even stranger, a baby’s body requires some additional genes that sneak in from the outside world. These tiny visitors travel inside of bacteria and other critters and affect the brain in ways that scientists are only beginning to understand

There’s a lot more later, but this is a good introduction of the idea that our brains, our very identities, are so intertwined with the external world, and especially so when we are small and quite helpless.

Parents really need to do their utmost best.

The child’s brain develops into its adult complexity via two processes called tuning and pruning.

Tuning means that neural connections that are used often become stronger. At a cellular level this happens through the myelin sheaths around axons (the neurons output) becoming thicker, facilitating signal transmission, and also through the dendrites (the inputs) becoming bushier.

Pruning means that neural connections that are not really used weaken and disappear. Here Feldman Barrett invokes one of my favourite principles when trying to understand the ruthless efficiency in human physiology: Use it or lose it.

In the case of the developing child, it starts with far more neurons than an adult brain needs. This is great for a brain that will need to adapt to a range of new situations. However, once the situation is known, the unused neurons and connections are ruthlessly pruned away to result eventually in a more efficient brain.

Feldman Barrett proceeds to give a number of compelling examples how the baby’s caretakers and the environment that they create play an absolutely crucial role in the physical development of the new neural network.

Little brains require a social world in order to develop typically. You’ve already learned that babies need certain physical inputs, such as photons of light bombarding their retinas, or their brains will never develop normal vision. It turns out that they also need social inputs from other humans who guide their attention, speak or sing to them, and cuddle them at key moments. If these needs aren’t met, things can go terribly wrong.

She then discusses a horrible example where thousands of Romanian babies found themselves in orphanages in the 1960s due to terrible leadership decisions.

In some orphanages, babies were warehoused in rows of cribs, with little stimulation or social interaction. Nurses or caregivers would come in and feed them, change them, and put them back in the cribs. That was about it.

[text ommitted]

As a consequence of this social neglect, the Romanian orphans grew up intellectually impaired. They had problems learning language. They had difficulty concentrating and resisting distractions, probably because nobody had shared attention with them, so their brains never developed the wiring for an effective spotlight. They also had trouble controlling themselves. Alongside the children’s mental and behavioral issues, their bodies were stunted, most likely because they grew up without caregivers to keep their body budgets solvent. This meant their brains never learned to budget effectively. A little brain wires itself to its environment, and when that environment is missing key elements for healthy body budgeting, critical brain wiring can be pruned away.

Based on this and far too many other observations, it is clear that children absolutely need to be well cared for, both physically and socially, in order to have a chance to develop into healthy adults.

This is a fundamental mechanism that can’t be easily remedied later.

She continues with this line of discussion into the now even more relevant poverty cycle phenomenon:

Research shows that early and long exposure to poverty is bad for the developing brain. Inadequate nutrition, interrupted sleep due to street noise, poor temperature regulation due to lack of heat or ventilation, and other circumstances of poverty may alter the development of the front of the cerebral cortex, namely the prefrontal cortex. This brain area is involved in a range of critical functions, including attention, language, and body budgeting. Scientists are still studying the ways that poverty affects brain development, but we do know that it’s linked to poorer performance in school and fewer years of education. These burdens ultimately increase a child’s risk of living in poverty when he grows up and has children of his own

Finally, this lesson is wrapped up with the observation that nature and nurture are deeply and intricately intertwined:

When it comes to the brain, simple distinctions like nature versus nurture are alluring but not realistic. We have the kind of nature that requires nurture. Your genes require a physical and social environment – a niche filled with other humans who shared your infant gaze, spoke to you with intent, set your sleep schedule, and controlled your body temperature – in order to produce a finished brain

Your Brain Predicts (Almost) Everything You Do

Readers of my personal blog might remember my story in 2019 about the brain being stuck in the dark bony cage we call “skull”, taking fairly limited sensory inputs, and in actual fact dreaming up all of one’s reality on demand, a story I later found out was also called transcendental idealism.

At the start of lesson 4, Feldman Barrett writes:

Scientists used to believe that the brain’s visual system operated sort of like a camera, detecting the visual information “out there” in the world and constructing a photograph-like image in the mind. Today we know better. Your view of the world is no photograph. It’s a construction of your brain that is so fluid and so convincing that it appears to be accurate.

… and then comes the brain stuck in a box story again!

From the moment you’re born to the moment you draw your last breath, your brain is stuck in a dark, silent box called your skull. Day in and day out, it continually receives sense data from the outside world via your eyes, ears, nose, and other sensory organs. This data does not arrive in the form of the meaningful sights, smells, sounds, and other sensations that most of us experience. It’s just a barrage of light waves, chemicals, and changes in air pressure with no inherent significance.

Most probably I picked this up somewhere on the echoing internet waves. Lex Fridman podcast would be my bet, but not the Feldman Barrett episode because that only came out in October of 2020.

However, this lesson is not only about your brain being stuck in a box, but the observation that your brain is constantly predicting what’s going to happen next.

This is perhaps even more extreme than you might guess.

What happens next still astounds me, even as a neuroscientist. If your brain has predicted well, then your neurons are already firing in a pattern that matches the incoming sense data. That means this sense data itself has no further use beyond confirming your brain’s predictions. What you see, hear, smell, and taste in the world and feel in your body in that moment are completely constructed in your head. By prediction, your brain has efficiently prepared you to act.

So yes, it seems we are mostly all in fact dreaming together in a highly synchronized fashion.

Your Brain Secretly Works with Other Brains

This aspect fascinated me during the podcast with Lex Fridman:

Part of being a social species, it turns out, is that we regulate one another’s body budgets – the ways in which our brains manage the bodily resources we use every day.

As if it wasn’t already trick enough that we regulate our own body budgets, we also have a profound effect on each other’s body budgets, an effect that we ideally put to good use for positive regulation.

The stress that we often experience due to interaction with our fellow humans plays a prominent role in this lesson.

In the workplace, having great colleagues that you can trust will leave more energy to do your work better:

When people work in an environment where they can learn to trust one another, they’ll have less burden on their body budgets, saving resources that can be invested in new ideas.

Profoundly, but probably not surprisingly, our prediction machines have a much easier time modelling humans that are similar to us, and conversely a much more difficult time working with fellow humans that are different from us:

When you have empathy for other people, your brain predicts what they’ll think and feel and do. The more familiar the other people are to you, the more efficiently your brain predicts their inner struggles. The whole process feels obvious and natural, as if you were reading another person’s mind. But there’s a catch—when people are less familiar to you, it can be harder to empathize. You might have to learn more about the person, an extra effort that translates into more withdrawals from your body budget, which can feel unpleasant. This may be one reason why people sometimes fail to empathize with those who look different or believe different things than they do and why it can feel uncomfortable to try. It’s metabolically costly for a brain to deal with things that are hard to predict.

This only underlines the fact that we really have no choice but to put in the best effort that we can to support and cultivate more diversity.

Like in many other situations, mother nature can’t be trusted here either, so we have to apply our humanity to make up for her failings.

Next Feldman Barrett discusses the central role of speech also in how we regulate each other’s stress levels:

Primates like monkeys and chimpanzees also use vision to regulate each other’s nervous systems. Humans are unique in the animal kingdom, however, because we also regulate each other with words. A kind word may calm you, as when a friend gives you a compliment at the end of a hard day. A hateful word from a bully may cause your brain to predict threat and flood your bloodstream with hormones, squandering precious resources from your body budget.

This is of course accurate and makes complete sense to me, but I have never thought about it in these explicit co-regulation terms.

What follows is an important warning that it really does not matter what the source of the stress is, if it continues, it will all pile up over time and it will harm you.

It’s important to understand that the human brain doesn’t seem to distinguish between different sources of chronic stress. If your body budget is already depleted by the circumstances of life—like physical illness, financial hardship, hormone surges, or simply not sleeping or exercising enough—your brain becomes more vulnerable to stress of all kinds. This includes the biological effects of words designed to threaten, bully, or torment you or people you care about. When your body budget is continually burdened, momentary stressors pile up, even the kind that you’d normally bounce back from quickly. It’s like children jumping on a bed. The bed might withstand ten kids bouncing at the same time, but the eleventh one snaps the bed frame. Simply put, a long period of chronic stress can harm a human brain.

Furthermore, contrary to the popular idiom, the wrong sorts of words can and will cause bodily harm:

But if you’re exposed to verbal nastiness continually for months and months or if you live in an environment that persistently and relentlessly taxes your body budget, words can indeed physically injure your brain. Not because you’re weak or a so-called snowflake, but because you’re a human. Your nervous system is bound up with the behavior of other humans, for better or for worse. You can argue what the data means or if it’s important, but it is what it is.

She explains that when you’re exposed to social stress within two hours from a meal, you even metabolize the foods from that meal much worse than you normally would.

She summarises the whole idea with the following observation, and perhaps this is that one thing we should take home with us:

The best thing for your nervous system is another human. The worst thing for your nervous system is also another human

Our interconnectedness and our personal freedom

Feldman Barrett has an extremeley timely piece at the end of this chapter about how our inescapable (and fantastic) interconnectedness has significant implications for our personal freedoms.

First, she makes clear how deeply we have always affected each other, and how inescapable this is:

After all, history is filled with examples of overcoming our biology so we can live our values. Other people carry germs, for example, that can make us sick or even kill us, but only in the most nightmarish cases do we legislate a solution that restricts our personal freedoms. More commonly, we cooperate and innovate. We invent soap, we bump elbows instead of shaking hands, we search for new medicines and vaccines, and so on. If this is insufficient, experts tell us we’re supposed to voluntarily isolate ourselves and practice social distancing. Even in a free society, our actions affect one another in ways that are, like viruses, often invisible to us.

… and then she completes this train of reasoning with the observation that personal freedom does have a great associated cost which is often exacted from others:

Scientists are often asked to make their research useful to everyday life. These scientific findings about words, chronic stress, and disease are a perfect example. There is a real biological benefit when people treat one another with basic human dignity. And if we don’t, there is also a real biological consequence, and it eventually trickles down to a financial and social cost for everyone. The price of personal freedom is personal responsibility for your impact on others. The wiring of all of our brains guarantees it.

It is clear that personal freedom has to be balanced carefully with cost to others, where the latter does have precedence.

Brains Make More than One Kind of Mind

She starts this chapter about the sometimes large differences differences between humans with the great example that people from Bali in Indonesia fall asleep when they are very afraid, while most Western folks are more likely to freeze on the spot, eyes wide, and gasp.

Perhaps even more fundamental than that, those same folks who grep up in Bali, or in the Illongot culture in the Philippines, don’t experience thinking and feeling as two separate concepts, like most Westerners do, but rather as a single thing.

She has more examples like this, but her overarching statement is that the same physical brain can produce and house quite different minds.

Importantly, variation is the norm.

Physical brains do have many common features, but minds by definition less so, because of the great adaptability of the underlying physical brains.

She gives another example pointing out that the Western idea of the body and mind as separate interacting constructs is also not the norm:

Brains have a lot of common features; minds, less so, because minds depend in part on micro-wiring that is tuned and pruned by 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 causes are identical. But in some Eastern cultures, such as those that practice Buddhism, mind and body are much more integrated.

As an aside, with all the work that is currently happening on the microbiome, showing how bacteria in your gut can and do affect your mood and personality, it is starting to look like the body-and-mind-in-one perspective could be closer to reality.

I highlighted the following paragraph, because (as an engineer and a data person) I found it an intriguing idea that your brain is summarising in real-time, down to a single metric called “affect”, the storm of external and internal data that it has to deal with.

In other words, affect is a single metric, or rather feeling, that summarises the complete state of your whole system.

Feldman Barrett writes:

Where does affect come from? In every moment – like right now, as you read these words – your hormones, organs, 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.

Finally, for better or for worse, it is possible to modify your mind with chemicals or with experiences:

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.

She mentions that one of the most challenging experiences in terms of changing your mind is moving to another culture.

The lesson is concluded with the following re-iteration of its central point, the malleability of the mind:

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.

Our Brains Can Create Reality

This is such an amazing chapter, which I really hope that you are able to read in its full form.

Nonetheless, here I’ll try to summarise the main gist.

Humans have the unique ability to create social reality.

The country that you live in, its name, the exact border surrounding it, the customs and the laws that you share with your fellow citizens, the right way to act at a party, and so on…

All of that was synthesized, created out of nothing, by a bunch of human minds.

Furthermore, we have demonstrated in many cases that we are able to keep these social realities operational for thousands of years.

Scientists do not know for sure how our brains developed this capability, but they suspect it is based on what Feldman Barrett calls the Five Cs:

We are able to draw a border and then invent a country with a national identity and a bunch of rules.
Millions of brains are subsequently able to communicate our new country and its rules to each other, and to keep each other up to date.
Our children learn how to operate by copying us. Similarly, we learn form each other by copying behaviour.
We cooperate on a geographical scale. The book quite casually mentions the example of food distribution, all the way from farms anywhere on the globe onto your plate for dinner.
This concept definitely needs a bit more space, so I’ll continue in the text below.

You’ll recall from a previous lesson that your brain is a (giant) network.

What was not emphasised in that lesson (or my notes), is the massive abstraction capability inherent in our brain architectures.

There are millions of neurons bringing in signals from the photosensitive receptors in your retina. After a few centimetres, those neural pathways connect in groups to summarising neurons, which combine each group’s information into a single signal.

All of those summarising neurons output into yet another layer of well-connected summarising neurons.

This process of successive summarisation continues all the way into the front of your brain, which contains the highest level of summarisation, that is, the fewest number of mega-neurons that aggregate effectively massive amounts of information from all of the lower levels indirectly feeding into them.

I hope that it is obvious now why this successive summarisation is also referred to as compression.

So what does this compression buy us humans?

This extreme level of compression enables us to think abstractly. Abstraction, together with the rest of the Five Cs enables us to create and maintain social reality.

Feldman Barrett wraps it up like this:

The wiring of your cerebral cortex makes compression possible. Compression enables sensory integration. Sensory integration enables abstraction. Abstraction permits your highly complex brain to issue flexible predictions based on the functions of things rather than on their physical form. That is creativity. And you can share these predictions by way of communication, cooperation, and copying. That is how the Five Cs empower a human brain to create and share social reality

No other animal brain can achieve the extreme levels of compression and abstraction required to create social reality.

As if this chapter in the book was not amazing enough, Feldman Barrett discusses the benefits and disadvantages of our reality creation superpower.

As an example of the disadvantages, I strongly agree with her view on our often stupid fascination with boxes:

For example, humans vary tremendously, like every animal species does. But unlike the rest of the animal kingdom, we organize some of this variation into little boxes with labels such as race, gender, and nationality. We treat the labeled boxes as if they’re part of nature when in fact we build them.

I would like to conclude this section with a part of the book’s conclusion to this inspiring chapter:

Social reality is a superpower that emerges from an ensemble of human brains. It gives us the possibility to chart our own destiny and even influence the evolution of our species. We can make up abstract concepts, share them, weave them into a reality, and conquer just about any environment – natural, political, or social – as long as we work together. We have more control over reality than we might think. We also have more responsibility for reality than we might realize.

A summary of the summary

For those of you that have no time to read the book or even these book notes, Feldman Barrett has a super compact summary of her seven and a half lessons in the epilogue.

The human brain is:

  • A brain that constructs such rich mental experiences that we feel like emotion and reason wrestle inside us
  • A brain that’s so complex that we describe it by metaphors and mistake them for knowledge
  • A brain that’s so skilled at rewiring itself that we think we’re born with all sorts of things that we actually learn
  • A brain that’s so effective at hallucinating that we believe we see the world objectively, and so fast at predicting that we mistake our movements for reactions
  • A brain that regulates other brains so invisibly that we presume we’re independent of each other
  • A brain that creates so many kinds of minds that we assume there’s a single human nature to explain them all
  • A brain that’s so good at believing its own inventions that we mistake social reality for the natural world