“Human intelligence depends on genes”: an interview with the author of popular science literature Asya Kazantseva
Miscellaneous / / April 22, 2022
Why is it so important to procrastinate sometimes and is it true that the lifestyle of a pregnant woman affects the sexual orientation of the fetus.
In January, we met with science journalist Asya Kazantseva to talk to her about the new book and work plans. A lot has changed since then, but we still decided to publish the interview, because it turned out to be interesting and informative.
Asya Kazantseva
Science journalist. Author of the books “Who would have thought!”, “Someone is wrong on the Internet!”, “The brain is material”.
About the future book by Asya Kazantseva
- You have already published three books, one of which was awarded the Enlightener Prize. Tell us how you usually work on them?
— They all have different backgrounds, but in general, the work usually follows the same pattern. At first, the book is cooked in the head for a long time. From an idea to the moment a person opens a file and starts writing it, it can take several years. And all this time he thinks about it: when he reads scientific articles, when he prepares for lectures or for interviews.
For example, when I was studying atTowerNational Research University Higher School of Economics” in a master’s program in cognitive science, then spent two years thinking about how my book would look. At first, I wanted to write non-fiction on experimental psychology. Then I thought that I would tell about modern methods of brain research. But in the end, they managed to find a compromise: in the book "The Brain is Material" there is both hardcore neuroscience and how it affects everyday life.
To write a book, in general, no more difficult than an article in some popular science magazine. But it takes perseverance. I once calculated that such a job would require about a thousand working hours. Provided that you already understand what you will write about. A thousand working hours is half a year if you do nothing else. Or even longer if you earn a living at the same time.
Do you have plans for a new book? What is her background?
- It was a long process of restructuring. First, in 2019, I went to Bristol for a master's degree in molecular neuroscience. And I thought that my next book would again be about the brain, and at the same time even more hardcore, serious and complex.
But the pandemic came, and my graduate school turned into a pumpkin. First there were three months of distance learning, then an academician, then another attempt at full-time education, which was again covered with a copper basin due to delta waves. As a result, we were unable to conduct laboratory work in neurobiology.
This whole story (and life) got me terribly. There were too many things that needed to be overcome. And so the priorities have changed. I suddenly decided that I would have a baby.
Having a baby is a socially acceptable excuse to work less if you're a woman.
This is an occasion to digress from the academic-intellectual, taking up the animal-emotional. It is legitimate to expect that when I have a baby, I will feel sweetness for him, and this will give me emotional support and recovery from all the troubles. It's also a reason for a book.
How sudden was this decision?
- In fact, both graduate school and a child are obvious career steps. I can earn a lot of money in a small amount of time - mostly corporate lectures. But in order to continue like this, you need to increase your fame and expertise.
Postgraduate study raises the status and gives a topic for a new book. The child does the same. Because my audience is growing with me. Many who read and listen to me either already have children, or they planned. But at the same time, we have quite a bit of popular science literature on this topic. Yes, there are many medical books - when some doctor from the height of his scientific school says: “Do this, but don’t do this,” and this does not always work.
There are almost no books that retell academic research about preparing for pregnancy and pregnancy itself. And I, of course, am the type of person who can write popular science retellings for these studies. I have a biological education that allows me to understand articles, and now there will be a personal interest.
Can you tell us what the content of this book will be? Or is it still a secret?
“I think it could end up being a two-volume book. The first volume will be about what happens to a woman and a child inside her until the moment of birth.
Because there are many things that are important, useful and yet not commonly known. For example, many people do not do genetic screening before having children. But at the same time, every second person is a carrier of one or another recessive mutations. And it can lead to a child's disability if the second partner has exactly the same mutation.
Of course, this rarely happens, because the mutations in mom and dad are usually different. But if it does happen, the consequences are very severe. And this could be prevented with little bloodshed if people checked their genes before having children.
For example, I know that I have a mutation in the MEFV gene. It's related to Mediterranean fever, it's a thing like Alzheimer's, but not in the head, but in the stomach - when amyloid proteins accumulate in the walls of internal organs and this causes paroxysmal pain.
The father of my unborn child does not have such a mutation, but there is a recessive mutation associated with the metabolism of fatty acids. Accordingly, we can have children without any additional tricks. Because the known recessive mutations do not intersect with us, and the child will definitely not start to get sick with anything like that, in the worst case, he will be a carrier.
But if it turned out that we have the same recessive mutation, then the process of having a child would be more complicated. It would be necessary to do pre-implantation genetic diagnosis: go for ECO, create embryos, genetically analyze them, and implant in the uterus only those of them who have not inherited a dangerous mutation from both parents at the same time.
In addition, the book will have a part about reproductive technologies. For example, if you're 30 or 35 and think you'll want a baby someday, but aren't ready yet, it makes sense to freeze your eggs or embryos. Because with a high probability, when you mature by the age of 40, there will be no more eggs.
But in general, the book begins with the chapter “You can not come” - about psychological, economic and sociological studies of whether people need children in principle.
Society presses: "We need to have a baby." However, many become unhappy from the fact that they have children. Because a child is a very big responsibility, burden, money, limitation of strength, time, freedom, and so on.
It is worth getting involved in reproduction only when you are seriously ripe for this. And if you are not ripe, then it is better to run away from someone who is trying to have a baby with you.
If you are not 100% sure of this decision, it will be worse for children, and for you, and ultimately for human society, because we still have overpopulation. So far, that's all I can say about the book.
How genes and fetal development affect a person
Does the intelligence of a person really depend on the intelligence of his parents?
Genes certainly play a role. In order to see how they affect a certain trait, it is most convenient to take twins.
They are of two varieties:
- Monozygotic - when there was one egg, it was fertilized by one sperm, but then in the early stages of embryonic development there was a division into two embryos. And they turned out to be two people, genetically identical.
- Fraternal - when two eggs are released in the same cycle, both are fertilized and implanted. It turned out two people, but there is no more genetic similarity in them than between any other brothers and sisters.
When you want to see if genes affect a trait, you find many pairs of identical and fraternal twins. And look how it is distributed in pairs.
For example, the hair color of identical twins will always be the same, but it can be different for fraternal twins. From this we conclude that genes are important here. But the tendency to dye their hair in a certain color - pink, green, yellow, black - in identical twins can be either the same or different. So, we can conclude: it is unlikely that we have a love gene for dyeing our hair.
If we look at any behavioral trait in this way, we find that identical twins always resemble each other more than fraternal twins. This is true for sense of humor, political views, openness to new things, propensity to smoke and severity of nicotine addiction.
It's the same with intelligence. The level of intelligence, as well as the level of school performance, in a pair of identical twins is significantly closer to each other than in a pair of fraternal twins. So yes, human intelligence depends on genes.
At the same time, there is a very interesting story here: the influence of genes on it increases with age. In childhood, environmental influences may be more effective. Let's say that some child was actively engaged, and he got good grades, but at the same time he was not very smart by nature.
When such a child grows up and gets rid of the influence of parents and teachers, he stops developing intellectually and begins to sit on the couch, read stupid books and watch stupid movies.
And if they didn’t do much with some child, but he was naturally smart, then as he grew older, he enrolls in the library, enters the university, finds smart friends, starts reading smart books.
This is an amazing but well-described phenomenon. Wednesday for kids affects stronger, and adults create their own environment depending on predispositions.
But here it should be emphasized that genes never set a trait absolutely, especially such a complex one as behavioral. They set some predispositions, some inclinations, some rate of reaction.
It is not written in the genes that you will have an IQ level of 114. But it is written that, most likely, it will be slightly above average. But 106 or 126 units - it depends on how many books you read, how lucky you are with the environment, and so on.
And more importantly, there is no single gene for intelligence. About 14,000 genes are active in the brain, and all of them affect certain aspects of its work at the cellular level. Somewhere more NMDA receptors are expressed on the membrane, somewhere the reuptake of serotonin works better, somewhere the hippocampus is more active.
All these little things add up to the fact that some person thinks and learns faster. Therefore, the best thing that can be done for a child is to give birth to him from the most intelligent person of all who are around.
- Did I hear you right, you said: "Genes also influence political views"? What is it like?
- Yes, that's right. This also came to light through twin studies. When their participants are questioned on the spectrum of political preferences, it turns out that the views of identical people are always closer to each other than those of heterogeneous ones.
If the first is a conservative, then the second is more often a conservative; if the first is a liberal, then the second is also a liberal. But here the influence genes not as strong as in the case of intelligence. They explain about 30% of all variability between people in relation to their political views.
Usually, when studying this issue, specialists are looking for a relationship with basic character traits - for example, with an interest in novelty. Because the more dopamine a person produces, the more he shows it. And openness to the new, in turn, can influence which parties and which political movement he chooses.
Here, on the one hand, molecular mechanisms are known: relationships have been established between openness to new things and the peculiarities of the work of dopamine receptors in the brain. On the other hand, openness to new things can influence which parties and which political movement a person chooses.
What determines a person's sexual identity? Whether a person is gay or heterosexual is also determined by genes?
- With orientation, just like with any other property of human behavior: the only universal answer is "Everything is complicated." Genes, environment, intrauterine development of the fetus affect.
In twin studies, we see that the same sexual orientation in identical twins is much more common than in fraternal twins. But not always. It happens that one of two identical twins - gayand the other is hetero. That is, genes do not determine this absolutely, but they increase or decrease the likelihood.
In addition, it is not so common to meet absolute gays or absolute hetero. People are bisexual to one degree or another, and then the environment can affect what features of their orientation they show more and more often.
I can be bisexual and date girls because I live in Moscow in the 21st century. But if I lived in some more conservative society, I would only hang out with men, because I'm okay with them too.
When we say that orientation is influenced by innate properties, it is important to understand that innate and genetic are not synonymous. Innate properties also affect sexual orientation. After all, innate and genetic are not synonyms. Congenital is what happened before the moment of birth, and genetic is what is determined at the moment of conception.
The course of pregnancy can affect orientation. For example, maternal stress increases the likelihood of the unborn child being homosexual.
It happens like this. First, the fetus develops genitals - according to the male or female type. Then, under the influence of sex hormones develops brain. And in this process desynchronizations are possible.
It is possible that the genitals were formed according to the male type, and the brain - according to the female. For example, because maternal cortisol, a stress hormone, crossed the placenta and suppressed the production of the baby's sex hormones.
This led to changes in the development of the fetal brain. By the way, this also explains the desire of people to perform a sex change operation. Because the differences between the brain and the body are so great that the body must be changed for a brain formed according to the male or female type.
What does “male and female brain development” mean? Are the brains of men and women different?
— We are talking here about a small number of nuclei of the hypothalamus associated with the administrative and economic part of the control of the body. That is, for example, women will have well-developed centers associated with the control of the menstrual cycle. But men do not, due to the fact that they simply do not have such a need. There are areas associated with sexual behavior, with those who will seem to a person more attractive, exciting.
But gender differences do not concern intellectual activity. Genes set the general principles for building the brain, features of work neurotransmitters and receptors, which can subsequently be reflected in behavior and set some kind of inclination. But at the same time, behavior is still shaped by the environment. And a person can learn a lot, regardless of whether he is a man or a woman.
The differences that are trying to find between the male and female brain weigh significantly less than the individual differences obtained in the course of training.
Therefore, the myth that the brain of a man and a woman is fundamentally different, in addition to a small number of areas in the hypothalamus, is my unloved one.
People ask about this too often, and you tell-tell-tell… And not only you, but all the neuroscientists of the world. And yet, for some reason, everyone believes that men and women are naturally predisposed to something.
About how learning affects a person and what to do to live better
How is the brain of a child different from the brain of an adult and an elderly person?
- The child's brain has more potential, but less realized. The number of connections between neurons in a one-year-old child is higher than that of a Harvard professor, but many of them formed quite chaotically and will gradually disappear if they are not useful for anything.
When a one year old is learning there is spoon, he directs it randomly: first into the mouth, then into the eye, then into the ear, then into the ceiling. But if you wisely organize his training, then every time he can bring porridge to his mouth, he will experience joy.
And it will help strengthen those neural circuits that allowed him to achieve his goal. So he will try to activate them again and again, they will intensify, this skill will be fixed. And the rest of the chains of neurons responsible for bringing the spoon to the ear or eye, on the contrary, will weaken.
In principle, any learning and any long-term memory is justified by the strengthening of connections between neurons that are involved in the implementation of a particular skill. Therefore, the brain develops throughout life. Just before the age of 25, he does it more quickly and actively. After this ability is not lost. But it takes more effort and time to master a new skill.
Another difference between the brains of children and adults is the amount of work memory. An adult can keep seven pieces of information in his head at the same time - for example, briefly remember a phone number.
It doesn't work for preschoolers. To test their short-term memory capacity, children are usually given play tests. Suppose they show several toy animals, then cover them with a napkin, remove one animal from under it, and the child must figure out which one.
For example, there were: a fox, a cat, a dog and a bunny. The fox was removed. A four-year-old child should cope with this task, since he can retain up to four pieces of information in memory. At the age of six, the amount of short-term memory increases, and there may already be six young animals.
On the one hand, it is more difficult for kids to keep information in their heads. On the other hand, if a child takes something into short-term memory, then it is easier to pass from there to long-term memory and is remembered more reliably for life. Therefore, we still remember the rhymes that we learned in the first grade.
- Is it worth it in this case to load the child with a complex program at an early age: mathematics, languages, and so on?
— There is no single answer, because all children are different. One intensive training mathematics comes easily and effortlessly. Then, it would seem, why not teach her? But there are also victims of parental ambitions, in which they stuff more than they would need. Thus, the ability to harmonious development is violated.
A child is a flexible and plastic creature, he can adapt to the requirements of the environment. He can be forced to learn the school curriculum by the age of nine, but it is not very clear why. Because he will learn it, most likely, of poor quality, like a trained monkey, at the level of "surrender and forget." Indeed, in order for the information to settle down in the head well, it takes not only time to master it, but also long pauses for idleness in between.
As for languages, kids have unique abilities for them. But only if the children live in a language environment. Their brain simply processes a large amount of speech and highlights patterns and patterns in it.
But this does not apply at all to language learning in class 2 hours a week because there just isn't enough material to accumulate. And learning a non-native language outside the environment is worth it only when the child has become older and more diligent and has developed a short-term memory for learning new skills.
In vain we are offended by our parents because they did not send us to English in early childhood.
Studies show that those who started learning a foreign language at the age of 8, and those who started it at 11, are at about the same level by the age of 16.
— And if, for example, someone started learning a language at the age of 30?
- This, of course, is worse. Most likely good pronunciation he will never reach, because articulation skills in childhood are formed easily, and in adulthood - with difficulty. For the same reason, I, for example, burr.
But at the same time, it is possible to learn the language in such a way as to use it adequately - to read, write, negotiate in it. Learning from a young age is simply more effective, but that doesn't mean it shouldn't be done as an adult.
- How do neurosciences interpret "insight" - when some idea came to mind, and a person suddenly experiences happiness from this? Is there anything you can do to experience this more often?
- Cognitive sciences intensively study the phenomenon of insight - a sudden, abrupt finding of an answer to some problem. There are a large number of laboratory-developed tests and special tasks in which a person needs to figure something out. For example, the classic problem is about nine points, which must be connected by four straight segments without lifting the pencil from the paper.
Usually a person fights for a long time over this puzzle, he does not succeed, he comes to a standstill. Then this task is cooked in the head, and as a result, restructuring occurs! A person realizes that he somehow misunderstood the rules and that they can be looked at differently.
Then it turns out that this problem is solvable. And a person experiences a euphoric feeling - insight. Experiments in the tomography show that at this moment the nucleus accumbens and the ventral tegmental area are activated - brain areas associated with pleasure, a sense of joy and reward.
Therefore, for insight, the process of restructuring and incubation is important - when you have loaded a task into your head and somewhere at an underlying level it is brewing by itself. This can lead to new connections between the knowledge you have downloaded and the knowledge you already have. And in the end you will come up with some new cool idea! She may even dream of you.
In general, when a person works with information, he constantly ponders it latently. This works well when the person is idling. Being idle is important.
- And how to mess around so that the brain likes it?
- Work with care. There is a focused mode, in which our attention is captured by something, and a defocused mode, in which our thoughts wander. And the second is much better for information processing.
For example, if you follow Facebook or play into a computer toy, then this, of course, is also a vacation, but not the one that leads to intuitive insights and insights. It is not fruitful, because you still process some information, albeit useless, and this prevents you from putting in your head what you have previously learned from a smart book.
You need to come up with a kind of recreation that does not require focusing attention, even on something interesting and pleasant. For example, sleep, walk, take a shower.
Are you training your brain? How to make sure that he remains young as long as possible?
- Sleep well. Sleep promotes neuroplasticity.
- Move. Movement provides a good blood supply to the brain.
- To study. To grow new neural connections, you need material. In order not to lose the skills of processing information, you need to constantly process it.
- Do stress management. If people are in chronic stress, this leads to excitotoxicity - a pathological process when neurons are so excited that they begin to die.
What about solving sudoku or doing crossword puzzles - does it help the brain stay younger?
“The problem here is that when solving Sudoku, we train only those parts of the brain that are responsible for solving Sudoku. But it's always a question of generalization: the extent to which the skills gained in solving Sudoku or solving a crossword puzzle can be applied to other tasks. There are many different studies, they show conflicting results.
The classes that give the most complex load on the brain are the study of foreign languages and game training on musical instruments. And, apparently, a university education is useful as a large and complex workload.
What kind of non-fiction books do you like?
— Daniel Dennett, Intuition Pumps. Dennett is a philosopher, but at the same time he is well versed in biology, evolution, artificial intelligence, and programming. He builds connections between these areas of knowledge and shows how they can be comprehended using philosophical tools.
Steven Pinker, The Clean Slate and The Best of Us. He is also an intellectual who summarizes information from many fields. Usually he takes some problem and describes how representatives of different sciences look at it. "Clean Slate" is a book about how genes and environment correlate in the formation of personality. The Best of Us is about how the level of violence in human society is falling and what unexpected factors influence it. One of them is typography. When it was invented, we were able to read books about others and thus understand that they are also people.
Alexander Markov, Human Evolution. He recently released the third volume, and this is important not to miss.
Nikolai Kukushkin, "Clap with one hand." This book won the Illuminator Award in 2020. Also about evolution, but in a very broad context. Namely, about how very old evolutionary events influenced the existence of our current society and the current psyche.
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