What affects human genes. How does heredity affect character, intelligence, and addictions, and is there an “aggression gene”? Tells the geneticist

27.09.2019 -

To what extent does genetics determine a person's personality? Is the role of upbringing and lifestyle important in the formation of character, or are its features genetically laid down in any conditions? These questions are of interest to scientists and ordinary people. It is not so easy to study the influence of genes, but experts nevertheless came to some unambiguous conclusions. I wonder to what extent your genotype determines your personality? We have selected several interesting facts, which explain the genetic and acquired differences in people.

"All in the father": the influence of genes on the character of a person

No one doubts that genes largely determine the appearance of a person. Who do you look like, mom or dad? is the most common question parents hear. So why can't character be inherited in the same way as eye color or body structure? It turns out it can.

However, the influence of genes on character is not direct, i.e. there is no kindness gene or greed gene. But they determine the sensitivity to hormones, and they already “rule” our emotions. So, the DRD4 gene determines the sensitivity of neurons to dopamine (the hormone of joy, anticipation, excitement). There are many variants (alleles) of this gene, they were even divided into groups: 2R, 3R, 4R ... 11R. Someone will have low sensitivity to dopamine, such a person can live in one place all his life, for him to change his usual environment is stress. Someone - on the contrary - the sensitivity to dopamine will be high. A carrier of this type of DRD4 gene will constantly seek adventure and change.

The genes that determine sensitivity to oxytocin are responsible for empathy, kinship, affection. And those that determine the sensitivity to testosterone "decide" how aggressive you are. In addition to hormonal settings, genes also affect the synthesis of enzymes, and those, in turn, are involved in many processes in the body. For example, the influence of genes on the oxidation of aldehyde has been proven. Yes, the same one that is formed after drinking alcohol and affects the degree of intoxication. Therefore, someone “cuts down” after one shot, and someone can drink liters.

How is a set of genes transmitted, is it possible to influence its formation? The human genotype is determined at the time of conception. The egg and sperm are carriers of paired chromosomes, which, when merged, exchange their parts in a random way. The result is a unique set of genes. Therefore, parents can have completely different children both externally and in character. But still, they inherit certain traits, just with varying degrees probabilities. And, yes, scientists cannot yet influence this probability.

Basic myths about genetics: what genes do not affect

It turns out that if the influence of genes is so great, then nothing depends on us? It's not me being lazy, it's my genetics - can I say that already? No, in fact, genes only set some limits, but do not dictate our every step. And some aspects are not affected at all. Below are a few examples where genes have nothing to do with:

Volitional decisions. Genes may determine a tendency to smoke or drink, but they do not prevent you from quitting. Every person can refuse bad habits just not everyone wants to.

Lifespan. Scientists estimated the influence of genes on this factor at 7%. The remaining 93% depend entirely on lifestyle.

The development of cancer. A predisposition to certain types of cancer can be inherited, this is a fact. But not all types of cancer. The genetic cause of development was proved only in 10% of the detected tumors.

Sports achivments. The genes will determine the type of figure, but they will not pump up the press cubes for you. Even if your family has three generations of athletes, this does not mean that your performance in sports - without regular training - will be higher than that of your peers.

Love for order. As well as punctuality, responsibility, politeness and many other personality traits that entirely depend on the environment and upbringing. The example of parents for children is very important, and no genes will teach you how to fold things and greet grandmothers at the entrance. Only mom and dad.

The study of the influence of genes on character and personality traits began relatively recently. And although scientists assign a large role to the genetic factor, they never tire of repeating that a lot depends on the person himself. And genetic predisposition It's just a predisposition.

Apart from external signs, individuals have differences from each other in physical characteristics and mental ability, mental and spiritual properties, in character. The worldview of a person, his environment, type of activity, and sometimes even appearance. Knowing what character is, one can better understand the essence of personality.

What is character in psychology?

The human character is influenced not only by psycho-emotional factors, but also by the features of work nervous system, habitat and social circle. A person's temperament is a combination of individual ones that determine the specifics of her behavior, lifestyle and interaction with others.

From the point of view of psychology, character combines the specific features of the mental and human, which are constant and stable. In most cases, it is formed throughout the entire life path and may be subject to some changes depending on lifestyle and environment.

Types of human character

There are the following types of character:

Choleric- often unbalanced, enthusiastic, with a sharp change in mood, quickly emotionally exhausted.
sanguine– mobile, productive, plunges headlong into interesting work, loses interest in a boring business, quickly reacts to a change in the situation and easily puts up with failures.
melancholic- often worried, vulnerable, impressionable, not very dependent on external factors.
Phlegmatic person- calm, hiding emotions, with a stable mood, balanced, calm, with high performance.

What determines a person's character?

Strengths of a person's character

The advantage may be positive traits person's character:

honesty;
diligence and conscientiousness;
stress tolerance;
independence;
discipline and diligence;
communication skills, resourcefulness and self-confidence;
punctuality.

With the help of the considered qualities, a person is able to achieve his goals, interact with others, be a reliable friend, life partner or partner. The development of such properties can contribute to the expansion of horizons, career growth and the emergence of new acquaintances.

Can a person change his character?

The question of whether it is possible to change the character of a person is always relevant, but there is no exact answer to it. There are a number of opinions regarding how the character of a person is revealed, each of which has the right to exist. Someone says that the basis of temperament lies in the genes or is formed in the first years of life, and all subsequent changes only slightly change the moral traits or add minor adjustments to them.

Another opinion is that throughout the entire life path an individual is able to change characteristic qualities depending on the environment that surrounds him, new interests and acquaintances. For example, the following changes may occur:

a person can become more emotional or, conversely, restrained;
become cautious, reasonable or reckless with age;
responsible or careless;
sociable or uncommunicative.

AT modern world a person has many different options for self-realization and changing some of his character traits. You can try to do this by changing activities, choosing an environment, changing your worldview and outlook on life. It is important that such actions are aimed at developing positive and worthy character traits.

Having understood what character is, you can try to understand the intricacies of its definition. An interesting point is the ability to determine the features of temperament by the outlines of the face:

a square-shaped face can speak of uncompromisingness and independence;
people with round face often smart and practical, but emotional;
oval - one of the signs of deep intelligence and diligence;
the triangular shape of the face often accompanies creative, creative people.

Sometimes character traits can surprise others with the fact that they are very contradictory. So, strong, brave people are closed, and merry fellows and jokers are the most true friends and reliable life companions. There may be diametrically opposed situations, because mother nature has not in vain endowed each person with individuality.

It is often said that a person has a complex, gullible, docile or terrible character. A variety of emotions is associated with the characteristics of the psychotype of a person, his state of mind, hereditary factors or upbringing. Knowing what character is allows you to understand individual characteristics personality. But it is important to remember that not only character can be decisive for assessing a person.

Psychogenetics describes how heredity factors affect the work of the psyche of animals and people. What kind mental illness are genetic and which are not? Can genes determine character? Is there a tendency to criminal acts hereditary? Psychogenetics answers all these questions. T&P talk about what scientists do within this scientific field.

In the English-language literature, the term “behavioral genetics” is used to define psychogenetics - “behavior genetics”. Some scientists say that this discipline lies at the intersection of psychology, neuroscience, genetics and statistics; others consider it a field of psychology that simply uses the methods of genetics to study the nature and origin of individual differences in humans and animals. The last definition seems to be closer to the essence of this scientific direction, since the structure and work of the psyche lies in the center of its attention, and the genetic component is rather a factor that influences it.

Psychogenetics of sex: a boy who was raised as a girl

Differences in behavior between people of different sexes is one of the issues that this area deals with. A textbook example that defined modern ideas about the psychogenetics of sex, the case of David Reimer is considered - a boy who was raised as a girl. David (who had a twin brother) was born into a poor Canadian family and in infancy survived an accident in which he lost his penis. The Raymers could not find a way out of this situation for a long time, and then accidentally learned about the theory of John Money (the creator of the term "gender"), who was sure that gender role is determined by upbringing, not DNA. Data to refute this did not exist at that time.

The level of development of surgery did not allow for a reconstructive operation, and David's parents decided on a sex change operation, hoping to raise their son as a daughter. The child was given a new name - Brenda. Brenda had toys, clothes, and activities for girls, her brother treated her like a sister, and her parents treated her like a daughter. However, it soon became clear that both psychologically and externally the girl was developing according to a masculine type. Brenda did not develop relationships at school (she was not interested in her peers, and the boys did not want to play with the girl), and in her diary she wrote that she had "nothing to do with her mother." In the end, the girl began to think about suicide, and then her parents decided to tell her the truth. Brenda made three unsuccessful suicide attempts, after which she decided to become a boy again. She passed hormone therapy and underwent surgery to restore primary sexual characteristics.

Dr. Mani's theory was refuted. David received substantial compensation for his suffering, but his psychological problems have not yet been fully resolved. As an adult, Reimer married and adopted three children, but soon after the death of his brother, who died from an overdose of antidepressants, he nevertheless committed suicide. At that time he was 38 years old.

Today we know that gender is determined genetically. It is impossible to make a person a man or a woman through education, pressure or manipulation: the mechanisms laid down by genetics are incomparably stronger than all this. That is why people with a diagnosis of "transgender" today are prescribed a sex change operation in order to bring the biological sex into line with the psychological one.

Phenylketonuria: an attack on neurons

Influence genetic mechanisms on the work of the psyche can manifest itself not only in fundamental issues like gender. Another example is phenylketonuria, an inherited metabolic disorder of amino acids, primarily phenylalanine. This substance is present in the proteins of all known living organisms. Normally, liver enzymes should convert it into tyrosine, which, among other things, is necessary for synthesis. But in phenylketonuria, the necessary enzymes are missing or lacking, so phenylalanine becomes phenylpyruvic acid, which is toxic to neurons. This leads to severe CNS damage and dementia.

Phenylalanine is found in meat, poultry, seafood, eggs, plant foods (in smaller amounts), as well as in carbonated drinks, chewing gum and other products, so for normal mental development Patients with phenylketonuria in childhood need to follow a diet and drink medications containing tyrosine.

Phenylketonuria is a vivid example of how a genetic failure, at first glance, not related to brain functions, affects its work in a critical way. At the same time, in the end, the fate of such patients in childhood depends on external factors: proper treatment intellectually, they develop on a par with their peers. If a child with impaired phenylalanine metabolism does not receive medication and does not follow a diet, mental retardation awaits him, and this is an irreversible diagnosis.

Pathology constructor: how schizophrenia is inherited

Today, scientists believe that schizophrenia, like autism, is inherited. According to research, the likelihood of getting sick is:

1% if the diagnosis was not observed in the family before;

6% if one of the parents has schizophrenia;

9% if it is observed in a brother or sister;

48% if we are talking about one of the identical twins.

At the same time, there is no specific “schizophrenia gene”: we are talking about tens or even hundreds of genome fragments in which anomalies are observed. We are all carriers of certain mutations, including those associated with schizophrenia, but they do not have any effect on our lives until they “get together”.

So far, scientists have not been able to find anomalies, the presence of which leads to schizophrenia. However, several problem areas in the human genome, they still managed to find. Chromosome 16 is considered the most famous among them: the absence of its 16p11.2 region may be one of the factors underlying autism and mental retardation. The doubling of 16p11.2 also seems to lead to autism, mental retardation, epilepsy, and schizophrenia. There are other chromosomal regions (15q13.3 and 1q21.1), mutations in which may be associated with mental illness.

The chance of inheriting schizophrenia for a child decreases as the age of the mother increases. But in the case of the father, the opposite is true: the older the father, the higher the likelihood. The reason is that as men age, more and more germ cell mutations occur, leading to de novo mutations in children, while this is not typical for women.

Experts have yet to solve the puzzle that represents the genetic architecture of schizophrenia. Indeed, de facto, this disease is inherited much more often than genetic studies show, even if relatives are separated and lead completely different lifestyles. The same picture, however, is observed in the case of hereditary obesity, abnormally high or abnormally short growth and other genetically determined parameters that deviate from the norm.

Mind from Grandma: Hereditary IQ

Today we know that many brain parameters are inherited, and not the result of exposure external environment. For example, the volume of the bark hemispheres 83% is inherited, and the ratio of gray and white matter in identical twins is almost identical. The level of IQ, of course, does not depend on the size of the brain, but it is also partly recognized as a hereditary parameter by 50%.

Unfortunately, about the mechanisms of inheritance high level We know no more about IQ today than we do about schizophrenia. More recently, 200 scientists studied genome fragments from more than 126,500 participants, only to find that the coding elements associated with IQ are on the 1st, 2nd and 6th chromosomes. Scientists are confident that the picture will become clearer when more people take part in the experiments. In addition, in the case of IQ, it seems that a new system for isolating the necessary sections of the genome is needed: you need to look for it on the X chromosome. Researchers have long noted that boys suffer mental retardation(IQ<70) чаще, чем девочки. Очевидно, так происходит из-за X-хромосомы: у мужчин она одна, тогда как у женщин их две. X-хромосома связана с более чем 150 расстройствами, в числе которых - гемофилия и мышечная дистрофия Дюшенна. Для того чтобы у девочки проявилась генетически обусловленная умственная отсталость (или гемофилия, или другая подобная патология), мутация должна произойти сразу в двух местах, тогда как в случае с мальчиком достаточно одной аномалии.

Anna Kozlova

geneticist, specialist of the laboratory of sports pharmacology and nutrition of the Republican Scientific and Practical Center for Sports (Minsk)

“There are a number of hereditary diseases, one of the symptoms of which is mental retardation: as a rule, these are violations of the number or structure of chromosomes. The classic example is Down syndrome; lesser known ones - for example, Williams syndrome (elf face syndrome), Angelman syndrome, and so on. But there are also mutations of individual genes. In total, there are more than a thousand genes in which mutations can lead to mental retardation of one degree or another, according to recent data.

In addition, there are a number of disorders that are polygenic in nature - they are also called multifactorial. Their appearance and development is determined not only by heredity, but also by the influence of the environment, and if we are talking about hereditary factors, then this is always the result of the action of not one, but many genes. Today it is believed that such diseases include schizophrenia, autism spectrum disorders, depressive spectrum disorders (clinical depression, postpartum depression), bipolar affective disorder (what used to be known as manic-depressive psychosis), manic syndrome, etc.

If we do not talk about obvious chromosomal diseases (say, Down's syndrome - trisomy of the 21st chromosome, Williams syndrome - microdeletion of chromosome 7q11.23, and so on), then there is, for example, a fragile X syndrome, in which a mutation of a specific a gene on the X chromosome that causes, among other things, mental retardation. In general, a fairly significant number of such pathologies are associated with mutations in the X chromosome, and they are well studied.

Regarding the influence of hereditary factors on IQ, as far as I know, there is no exact and unambiguous answer yet (except for situations where one of the symptoms of a hereditary disease is a decrease in intelligence). In general, only the so-called “reaction norm” is genetically determined, that is, the range of variability of a trait, and how this is realized within the range is already associated with environmental conditions (upbringing, training, stress, living conditions). It is believed that intelligence is just a classic example of a trait for which a fairly wide range is genetically determined, and not a specific IQ value. But at the same time, there are a number of polymorphic alleles, for which, for example, an association with the preservation of the level of cognitive abilities under conditions of increased physical and mental stress has been shown. According to various sources, the influence of hereditary factors on memory ranges from 35% to 70%, and on IQ and attention - from 30% to 85%.

Psychogenetics deals with the study of how hereditary factors affect the mental qualities of a living being. For example, the influence of individual genetic characteristics on temperament, aggressiveness, indicators of introversion-extraversion, novelty search, avoidance of harm (damage), dependence on reward (encouragement), IQ, memory, attention, reaction speed, speed of disjunctive response (responding to situations with mutually exclusive choice) and other qualities. But in general, unlike most morphological and biochemical traits, mental characteristics are less dependent on genetics. The more complex the behavioral activity of a person, the greater the role of the environment and less of the genome. That is, for simple motor skills, heritability is higher than for complex ones; for indicators of intelligence - higher than for personality traits, and the like. On average (the scatter of data, unfortunately, is quite large: this is due to differences in methods, sample sizes, insufficient consideration of population characteristics), the heritability of mental characteristics rarely exceeds 50–70%. For comparison: the contribution of genetics to the type of constitution reaches 98%.

Why is that? In particular, because a huge number of genes are involved in the formation of these features (complex and complex), and the more genes are involved in any process, the lower the contribution of each individually. For example, if we have ten types of receptors that are susceptible to one neurotransmitter, and each is encoded by a separate gene, then a decrease in expression or even a knockout in one of the genes will not turn off the entire system as a whole.

Icons: 1) A.L. Hu, 2) Aenne Brielmann, 3) Michael Thompson, 4) Alex Auda Samora - from the Noun Project.

Health ecology: Genes are a section of the DNA molecule that is responsible for building one protein or RNA of the body. Genes are responsible for the innate characteristics, psychotype and health of the child. Genes pass programs to a greater extent not to the next generation, but through the generation, that is, your genes will not be in your children, but in your grandchildren. And your children have the genes of your parents.

Genes - a section of a DNA molecule that is responsible for building one protein or RNA of an organism. Genes are responsible for innate characteristics, psychotype and healthchild. Genes pass programs to a greater extent not to the next generation, but through the generation, that is, your genes will not be in your children, but in your grandchildren. And your children have the genes of your parents.

Genes determine our physical and mental characteristics, genes specify that we, as humans, cannot fly and breathe underwater, but can learn human speech and writing. Boys are easier to navigate in the objective world, girls - in the world of relationships. Someone was born with an absolute ear for music, someone with an absolute memory, and someone with the most average abilities.

By the way, it depends on the age of the parents: the average age of parents who have brilliant children is 27 for mothers and 38 for fathers.

Genes determine many of our personality traits and tendencies. In boys, it is a tendency to engage in cars, not dolls. Genes influence our individual predispositions, including disease, antisocial behavior, talent, physical or intellectual activity, and so on.

It is important to always remember: propensity pushes a person, but does not determine his behavior. Genes are responsible for propensity, a person is responsible for behavior. Yes, and you can work with your inclinations: develop some, make them loved, and leave some out of your attention, extinguish them, forget ...

Genes determine the time when some of our talent or inclination will manifest or not.

I got at the right time, when the genes are ready - I did a miracle. Missed on time - you fly by. Today, the susceptibility to the educational process is open - a "white sheet" or "absorbs only the good", and tomorrow, as the king from the film "An Ordinary Miracle" said: "My grandmother will wake up in me, and I will be weird."

Genes determine when our sex drive wakes up and when it falls asleep. Genes affect both happiness and personality traits.

After analyzing data from more than 900 pairs of twins, psychologists at the University of Edinburgh found evidence for the existence of genes that determine character traits, a tendency to be happy, and the ability to tolerate stress more easily.

Aggressiveness and goodwill, genius and dementia, autism or extraversion are passed on to children from their parents as inclinations. All this can be changed by upbringing, but to varying degrees, since the inclinations can be of different strengths. Whether a child is taught or not is also related to his genetics. And here we note: healthy children are quite trainable. Human genetics makes man an exceptionally trainable being!

Genes are the carriers of our abilities, including the ability to change and improve. Interestingly, men and women have different opportunities in this regard. Men are more likely than women to be born with one or another deviation: among men there are more of those who will be very tall and very short, very smart and vice versa, talented and idiotic. It seems that nature is experimenting on men ... At the same time, if a man was born this way, it is very difficult for him to change this during his life. A man is tied to his genotype, his phenotype (external manifestation of the genotype) changes little.

Born long - long and stay. A short man can rise 1-2 centimeters with the help of sports, but no more.

For women, the situation is different. Women are born more on average the same, among them there are fewer biological, genetic abnormalities. More often of average height, average intelligence, average decency, idiots and sludge among women are less than among men. But also outstanding intellectually or morally - similarly.

It seems that evolution, conducting experiments on men, decides not to take risks on women and invests in women all the most reliable. At the same time, individual (phenotypic) variability in women is higher: if a girl was born small relative to others, she will be able to stretch 2-5 cm (more than a guy can) ... Women have more freedom from their genotype, they have a greater opportunity than men , change yourself.

Genes give us our capabilities, and genes limit our capabilities.

A proud wheat ear grows from a grain of wheat, and a beautiful branchy apple tree grows from an apple tree seedling. Our essence, our inclinations and the ability to realize ourselves are given to us by our genes. On the other hand, only an ear of wheat will grow from a grain of wheat, only an apple tree will grow from an apple tree seedling, and no matter how much a frog puffs up, it will not swell into a bull. She doesn’t even have enough strength to burst from the effort.

Man is also a part of nature, and all of the above is true for him. Genes predetermine the limits of our capabilities, including our ability to change ourselves, strive for growth and development. If you are lucky with your genes, you have managed to perceive the influence of your parents and teachers, and have grown up as a developed, decent and talented person. Thanks to parents! If you are less fortunate with genes, and you (suddenly!) were born down, then in the best environment only a well-bred down will grow out of you. In this sense, our genes are our destiny, and we cannot directly change our genes, our ability to grow and change.

How much genetically inherent in us is a very controversial issue (the interaction of heredity and environment is studied by psychogenetics).

Rather, it is true that the more a person moves away from the animal world, the less in him is innate and more acquired. For now, it must be admitted that there is a lot of innateness in most of us. On average, according to geneticists, genes determine human behavior by 40%.

Under favorable conditions and a good educational process, a possible negative predisposition may not be realized, or it may be corrected, "hidden behind" the influence of neighboring awakened genes, and a positive predisposition, sometimes hidden, may appear. Sometimes a person (child) simply does not know his capabilities, and categorically "putting an end to it", saying that "a swan will not grow out of this ugly duckling" is dangerous.

Another danger, another risk is to waste time and energy on a person from whom nothing worthwhile can come out of. They say that anyone can become a genius, and theoretically it is. However, practically one needs thirty years for this, while another needs three hundred years, and it is unprofitable to invest in such problematic people. Sports coaches argue that it is innate talent, and not training methodology, that is the most important factor in shaping a future champion.

If a girl was born a brown-haired woman with green eyes and a "predisposition" to be overweight, then, of course, you can dye your hair and put on colored lenses: the girl will still remain a green-eyed brown-haired woman. But whether her "predisposition" will be embodied in the fifty-large sizes worn by all her relatives largely depends on herself. And even more so, it depends on her whether by the age of forty, sitting in this fifty-large size, she will scold the state and the unfinished life (as all her relatives do) or find many other interesting activities for herself.

Can a person change, sometimes overcome, and sometimes improve his genetics? The answer to this question cannot be general, since this is also given individually genetically. The most important thing is that today no specialist will give you a definite answer, you will find the answer yourself, only by starting to work with yourself, starting to change yourself.

Whether it is possible to change this child (or ourselves) in the direction we need, we can understand only by experience, starting with this child (or with ourselves). Get started! Genes set opportunities, it depends on us how we realize these opportunities. If you have good genetics, you can make it even better and pass it on to your children as the most precious gift.

Our DNA remembers what kind of childhood we had, there are observations that habits, skills, inclinations and even manners are genetically transmitted. If you have developed good manners, beautiful manners, set a good voice, accustomed yourself to the daily routine and responsibility, then there is a good chance that sooner or later this will enter the genotype of your last name.

Genes determine our inclinations, our abilities and inclinations, but not our destiny. Genes determine the launching pad for activity - for some it is better, for others it is more difficult. But what will be done on the basis of this platform is no longer the concern of genes, but of people: the person himself and those who are close to him.

Genetics can be improved - if not always in one's own destiny, then definitely in the destiny of one's own family. Good luck genetics!

Bad genetics and upbringing

Children from boarding schools often have poor genetics - not only in terms of health, but also in terms of inclinations and character traits. If ordinary good parents without special training take a child to raise, they can struggle for years with the fact that the child steals, does not study, lies, and so on in full. Nobody canceled genetics.

It is in connection with this that one must be very careful when people want to take a child from an orphanage to raise. There were cases when a family adopted a girl at the age of 9 months, whose mother was a prostitute, and despite the values of this family, at the age of 14-16, the girl fully "remembered" her mother.

This will be of interest to you:

On the other hand, these difficulties should not be exaggerated. Hidden problematic scenarios of difficult children are not the most common option; more often, successful or problematic inclinations of children are visible from childhood. In addition, the experience of A.S. Makarenko more than convincingly says that with quality education, children with almost any genetics turn into worthy people. published

Psychogenetics of sex: a boy who was raised as a girl

Differences in behavior between people of different sexes is one of the issues that this area deals with. A textbook example that determined modern ideas about the psychogenetics of sex is the case of David Reimer, a boy who was raised as a girl. David (who had a twin brother) was born into a poor Canadian family and experienced an accident in infancy in which he lost his penis. The Raymers could not find a way out of this situation for a long time, and then accidentally learned about the theory of John Money (the creator of the term "gender"), who was sure that gender role is determined by upbringing, not DNA. Data to refute this did not exist at that time.

The level of development of surgery did not allow for a reconstructive operation, and David's parents decided on a sex change operation, hoping to raise their son as a daughter. The child was given a new name - Brenda. Brenda had toys, clothes, and activities for girls, her brother treated her like a sister, and her parents treated her like a daughter. However, it soon became clear that both psychologically and externally the girl was developing according to a masculine type. Brenda did not develop relationships at school (she was not interested in her peers, and the boys did not want to play with the girl), and in her diary she wrote that she had "nothing to do with her mother." In the end, the girl began to think about suicide, and then her parents decided to tell her the truth. Brenda made three unsuccessful suicide attempts, after which she decided to become a boy again. She underwent hormonal therapy and had surgery to restore her primary sexual characteristics.

Dr. Mani's theory was refuted. David was paid significant compensation for his suffering, but his psychological problems were never fully resolved. As an adult, Reimer married and adopted three children, but soon after the death of his brother, who died from an overdose of antidepressants, he nevertheless committed suicide. At that time he was 38 years old.

Phenylketonuria: an attack on neurons

The influence of genetic mechanisms on the work of the psyche can manifest itself not only in fundamental issues like gender. Another example is phenylketonuria, an inherited metabolic disorder of amino acids, primarily phenylalanine. This substance is present in the proteins of all known living organisms. Normally, liver enzymes should convert it into tyrosine, which, among other things, is necessary for the synthesis of neurotransmitters. But in phenylketonuria, the necessary enzymes are missing or lacking, so phenylalanine becomes phenylpyruvic acid, which is toxic to neurons. This leads to severe CNS damage and dementia.

Phenylalanine is found in meat, poultry, seafood, eggs, plant foods (in smaller amounts), as well as carbonated drinks, chewing gum and other products, so for normal mental development, patients with phenylketonuria in childhood need to follow a diet and drink medication, containing tyrosine.

Phenylketonuria is a vivid example of how a genetic failure, at first glance, not related to brain functions, affects its work in a critical way. At the same time, in the end, the fate of such patients in childhood depends on external factors: with proper treatment, they develop intellectually along with their peers. If a child with impaired phenylalanine metabolism does not receive medication and does not follow a diet, mental retardation awaits him, and this is an irreversible diagnosis.

Pathology constructor: how schizophrenia is inherited

Today, scientists believe that schizophrenia, like autism, is inherited. According to research, the likelihood of getting sick is:

1% if the diagnosis was not observed in the family before;

6% if one of the parents has schizophrenia;

9% if it is observed in a brother or sister;

48% if we are talking about one of the identical twins.

So far, scientists have not been able to find anomalies, the presence of which leads to schizophrenia. Nevertheless, they still managed to find several problem areas in the human genome. Chromosome 16 is considered the most famous among them: the absence of its 16p11.2 region may be one of the factors underlying autism and mental retardation. The doubling of 16p11.2 also seems to lead to autism, mental retardation, epilepsy, and schizophrenia. There are other chromosomal regions (15q13.3 and 1q21.1), mutations in which may be associated with mental illness.

Mind from Grandma: Hereditary IQ

Today we know that many brain parameters are inherited, and not the result of environmental influences. For example, the volume of the cerebral cortex is inherited by 83%, and the ratio of gray and white matter in identical twins is almost identical. The level of IQ, of course, does not depend on the size of the brain, but it is also partly recognized as a hereditary parameter by 50%.

Unfortunately, today we know no more about the mechanisms of inheritance of high IQ than about schizophrenia. More recently, 200 scientists studied genome fragments from more than 126,500 participants, only to find that the coding elements associated with IQ are on the 1st, 2nd and 6th chromosomes. Scientists are confident that the picture will become clearer when more people take part in the experiments. In addition, in the case of IQ, it seems that a new system for isolating the necessary sections of the genome is needed: you need to look for it on the X chromosome. Researchers have long noted that boys are mentally retarded (IQ

What affects human genes. How does heredity affect character, intelligence, and addictions, and is there an “aggression gene”? Tells the geneticist

"All in the father": the influence of genes on the character of a person

Basic myths about genetics: what genes do not affect

What is character in psychology?

Types of human character

What determines a person's character?

Strengths of a person's character

Can a person change his character?

Psychogenetics of sex: a boy who was raised as a girl

Phenylketonuria: an attack on neurons

Pathology constructor: how schizophrenia is inherited

Mind from Grandma: Hereditary IQ

Anna Kozlova

Psychogenetics of sex: a boy who was raised as a girl

Phenylketonuria: an attack on neurons

Pathology constructor: how schizophrenia is inherited

Mind from Grandma: Hereditary IQ

Anna Kozlova

geneticist, specialist of the laboratory of sports pharmacology and nutrition of the Republican Scientific and Practical Center for Sports (Minsk)

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