Issues related to the inheritance of the intellectual abilities of parents by a child have long been discussed by society. The giftedness of a small person primarily depends on the mother, since the harmonious development of the fetus is largely determined by her behavior and physical condition during pregnancy. However, the influence of genetic information is no less important.

On the transfer of the "mind gene": "for" ...

Back in the twentieth century, scientists studied a group of identical twins. It turned out that intellectual abilities are transmitted only through the X chromosome. Therefore, giftedness is not transmitted to the son from the father, since in this case the child receives only the Y chromosome, which is in no way associated with talents. The general rules are as follows:
. if the father is gifted, the probability that his intellectual abilities will be transferred to his son is 0%, and to his daughter - 25%;
. with high IQs of the mother, the son can get all 100%, and the daughter - 75%;
. if both parents are talented, then the boy inherits the intellect of the mother, and the girl inherits the father (the male X chromosome suppresses the female).

Interestingly, the age of the parents also matters. A lady of 35-40 years old has a higher chance of giving birth to a talented child (as well as a mentally retarded one, by the way) than a woman of 18-20 years old. The chances of giving birth to a capable baby increase if a mature mother chooses a young man as a father.

... and "against"

However, there are diametrically opposed opinions in scientific circles. In particular, Wolf Kitses cited a selection of such facts in his diary:
. Identical twins raised together do not reach the maximum in mental development, as they are very focused on each other. However, if they are separated (or one child dies), the individual's IQ may increase by 10 points. This example clearly illustrates the important role of external developing, and by no means hereditary factors.
. It was found that, on average, the IQ level is highest for the youngest student in the class and the eldest son in the family (ceteris paribus). The youngest student often turns out to be the weakest, and therefore he has to develop more actively in order to “catch up and overtake” his classmates. As for the first-born, researchers believe that in families when raising children, there are intellectual niches that differ from each other. Usually the first child gets maximum developmental attention, which has a positive effect on his intellect.

In addition, scientists have determined that the population of developed countries is rapidly getting smarter. Experts believe that the intelligence of people is growing due to the emergence of new types of schools, expanding access to education, acquiring innovative ways of learning, implementing the fruits of scientific progress, etc. All these moments make it possible to really interest talented children and develop their mental abilities.

Instead of an epilogue

It seems that having inherited the “mind genes” from their parents, children cannot grow up to be truly talented on their own. In order to develop the abilities of a gifted child, parents need to make a lot of efforts. Often a mother or father - geniuses and talents recognized in society - do not devote enough time to their children (due to their own employment). So from the kids subsequently grow personalities, so little resemblance to gifted parents. But geniuses are often raised by quite ordinary people who do not shine with special achievements and merits. Nevertheless, such seemingly inconspicuous individuals invest a lot of strength and health in the upbringing of their children, thanks to which the talent of the younger generation can be fully realized.

There are also such data from American physiologists: 2/3 of personality development depends on the natural abilities of the child, 1/3 - on the influence of upbringing and environment. So, in addition to the hereditary level of intelligence, the success and susceptibility of the baby to learning is greatly influenced by his self-confidence, consciousness, friendliness, anxiety and many other factors. Hereditary abilities are just start-up capital that needs to be wisely disposed of.

Moms all over the world now have a great reason to praise themselves for the intelligence of their children. According to a new study, children most often inherit intelligence from their mothers.

Genes responsible for intelligence

Common sense dictates the logical conclusion that intelligence is inherited by a child from both parents (and sometimes this is actually the case), but most often the genes located on the X chromosome, usually inherited from the mother, are responsible for the mental development of the baby.

The results of the study clearly show that certain genes act differently depending on whether they are inherited from the mother or from the father.

The genes responsible for intelligence and predisposition to learning are located on the X chromosome. Because women have two X chromosomes and men have only one, the mother is twice as likely to inherit intelligence as the father. According to the study, the genes responsible for intelligence, inherited on the father's X chromosome, are most often deactivated.

Results of previous studies

If you're still not ready to believe the results of the new study, it's worth taking a look at the results collected over several decades.

As early as 1994, representatives of the Medical Research Council began interviewing people between the ages of 14 and 22. To date, researchers have interviewed about 13,000 people. After an intelligence quotient (IQ) test, the best predictor of outcome, after educational level and socioeconomic status, was the mother's intelligence.

Social factors

In addition to scientific research, there is also a social theory that explains why mothers are responsible for the intelligence of their children. According to statistics, it is mothers who spend more time with children and are responsible for their upbringing and environment just at the time when the child’s mental activity is actively developing and developing.

Most often, smart mothers raise smart children, artistically gifted parents raise artists, and musically gifted children most often grow up in musical families.

However, do not write off dads. Scientists estimate that less than 50% of human intelligence is due to genetic inheritance. About 40-60% of intelligence is formed in children due to external factors.

Smart people can sincerely thank their mothers, because according to research, it is mothers who are able to pass on the wisdom gene. Thus, the gender stereotype that has existed for centuries may soon disappear, and female wisdom will become the most important criterion for men when choosing a partner.

Based on this theory, "conditional genes" were discovered that behave differently depending on the origin. In general, these genes have biochemical links that make it possible to trace their origin and even indicate whether they are active or not in flow cells. Interestingly, some of these "conditional genes" only work if they are passed down from the mother. If the same gene is inherited from the father, it is deactivated. It is clear that other genes work in reverse order and are activated only if they come from the father.

It is the mother's genes that are directly responsible for the development of the cerebral cortex, and the father's - for the development of the limbic system.

We know that intelligence has a hereditary component, but a few years ago we thought that a lot depends not only on the mother, but also on the father. However, several studies have shown that children are more likely to inherit their mother's mindset because intelligence genes are located on the X chromosome.

One of the first studies in this area was carried out in 1984 at the University of Cambridge, followed by many others. These studies analyzed brain coevolution and genome conditioning. This led to the conclusion that maternal genes make the greatest contribution to the development of thinking.

During the first experiment, the researchers created embryos of rats that had only the genes of the mother or father. But when it came time to transfer them to the uterus of an adult rat, the embryos died. Thus, they found more significant "conditional genes" that are activated only if they were inherited from the mother. These genes are vital for the proper development of the embryo. On the other hand, the genetic heritage of the father is very important for the growth of the tissue that will form the placenta.

Then the researchers suggested that if these genes are important for the development of the embryo, it is also likely that they can play an important role in the life of animals and humans, perhaps even influence the development of brain functions. The problem was how to prove this idea, because embryos with genes from only one parent died quickly.

The researchers found a solution: they found that embryos could survive if normal embryonic cells were maintained and the rest manipulated. So they created several genetically engineered lab mice that, surprisingly, didn't develop the same way. Interestingly, rats with an extra dose of maternal genes developed faster brains and heads, but their bodies remained small. In the situation with paternal genes, it was the other way around - the rats had small heads, but huge torsos.

After a more detailed analysis, the researchers found cells in six different parts of the brain that contained the genes of only one of the parents and controlled various cognitive functions, from eating habits to memory.

In the early days of embryonic development, any cell can appear anywhere in the brain, but as the embryos mature and grow, cells with paternal genes accumulate in certain areas of the brain: the hypothalamus, amygdala, preoptic region, and septum.

These areas are part of the limbic system, which is responsible for our survival and functions such as sex, nutrition, and aggression. However, the researchers did not find paternal cells in the cerebral cortex, where the most advanced cognitive functions such as intelligence, thinking, language and planning are developed.

New research, new discoveries

Of course, scientists continue to explore this theory. For example, Robert Lerke showed that a significant part of children's intelligence depends on the X chromosome. He also proved that because women have two X chromosomes, they are twice as likely to pass on intelligence.

Recently, researchers from the University of Ulm (Germany) studied the genes associated with brain damage and found that many of them, especially those responsible for cognition, are located on the X chromosome. Therefore, it is no coincidence that mental retardation in 30% more common in men.

But perhaps one of the most interesting results from these experiments comes from a longitudinal analysis conducted by the Department of Medical Research and Social Sciences in Glasgow, Scotland. This study has interviewed 12,686 young people aged 14 to 22 every year since 1996. The researchers took into account several factors, from skin color and education to socioeconomic status. They found that the best predictor of intelligence was the mother's IQ. In fact, the IQs of young people differed, on average, by only 15 points compared to their mothers.

Genetics is not the only factor

In addition to genetics, we can also find other studies that show that the mother plays an important role in the intellectual development of children, for example, through physical and emotional contact. Some studies show that the intellectual development of the child also depends on direct contact with the mother.

Researchers at the University of Minnesota have found that children who are strongly attached to their mothers are able to play complex symbolic games as early as age two, are more persistent, and show less frustration during problem solving.

This is because a strong bond gives children the security they need to explore the world and the confidence to tackle complex challenges without losing heart. In addition, mothers are better able to support their children in solving problems, thereby further stimulating their potential.

The importance of emotional relationships for brain activity has been demonstrated by researchers at the University of Washington, who have shown for the first time that a strong bond and mother's love is critical for the development of certain parts of the brain. For seven years, these researchers analyzed how mothers treat their children. They found that when mothers were emotionally supportive and properly met the intellectual and emotional needs of their children, their hippocampus at age 13 was 10% higher than that of children whose mothers were emotionally distant. It is worth mentioning that the hippocampus is a region of the brain associated with memory, learning, and behavior in stressful situations.

It is estimated that about 40-60% of intelligence is hereditary. This means that the remaining percentage depends on the environment, stimulation and personality characteristics. In fact, what we call intelligence is nothing more than the ability to solve problems. But an interesting fact is that even during simple mathematical or physical exercises, the limbic system is also involved, because our brain works as a whole. Thus, even if intelligence is closely related to the function of rational thinking, it is also influenced by intuition and emotions, which, from a genetic point of view, depend on paternal contributions.

Moreover, we must not forget that even if the child has a high IQ, we must stimulate this intelligence and feed it throughout life with new knowledge. Otherwise, this intellect will become inactive.

Despite the fact that female genetics largely influence the mental development of the child, fathers should not be upset, because their contribution is also important, especially emotionally. The IQ we are born with is important, but not decisive.

The life of each person begins with the fusion of two germ cells, maternal and paternal gametes containing chromosomes. Chromosomes carry genes, and each of them is its own set, they are redistributed randomly, forming new combinations. This is how we are different from each other!

A modern American researcher, one of the leading experts in the field of behavioral genetics, Robert Plomin, claims that each of us is a unique genetic experiment that will never be repeated. Even the chance that children of the same parents will get the same set of genes is one chance in 64 trillion possibilities. The exception is twins, but even there there is no one hundred percent match in the genetic set.

Not so long ago, there was an opinion that health is transmitted through the maternal line, and intelligence through the paternal line, but the inquisitive minds of scientists did not stop at research. And here are the interesting conclusions they got: it is proved that among women the average level of intelligence prevails, and among men there are often deviations in both directions. Why is this happening?

It turns out that scientists conducted the first large-scale genetic study in this regard and came to the conclusion that the power of intelligence is inherited through the mother's line, and not the father, as previously thought.

It is the mother's genes, as it turns out, that are directly responsible for the development of the cerebral cortex, and the father's - for the development of the limbic system. In other words, you took intellect from your mother, and your typical emotional state from your father.

Moreover, some other studies have shown that people inherit their mother's intelligence because intelligence genes are located on the X chromosome.

The genes that “transmit” the gifts of intelligence by inheritance are located on the X chromosomes. Women have two such chromosomes (XX), and men have only one (XY), so the genes responsible for intelligence are more active in women, and a genius dad can pass on his high IQ to his daughter, but not to his son.

Intelligence is transmitted along the X chromosome. If a daughter is born, then the intellect from the genius-father will definitely be transferred to her genes along with the same X chromosome that determines her sex. After all, she will have two X chromosomes: one is paternal, and the second is one of the maternal. Therefore, the sons who have shown remarkable abilities and talents are only obliged to their mother for this gift!

But there are other factors

Recently, researchers at the University of Ulm in Germany found that genetics is not the only reason for high intelligence. Whether you are smart or not is also influenced by other factors.

The main such additional factor is the degree of attachment to the mother, especially at the age of two years. Children who regularly played complex games with them that required character recognition later grew up to be smarter adults than most of their peers.

The second factor is love. If the emotional needs of children under the age of 13 were almost completely met, 10% more cells formed in their hippocampus than those who were emotionally distant from their mother.

Now scientists say that intelligence is only 50% due to genetics, and the rest - to the environment.

Oh sure. All of our traits are heritable to some degree—even those that are seemingly completely acquired, like tan and French*.

In order not to end the article right here, let's try to be specific about the question.

On what does intelligence depend more - on heredity or on upbringing?

All our traits depend partly on heredity and partly on environmental conditions. But the strength of the influence of the environment for different signs is different. For example, livestock breeders know that even from a completely outbred cow, more milk can be obtained through good feeding and care (environmental influences). But it is impossible to increase the fat content of milk in the same way - this parameter almost completely depends on heredity.

Human intelligence, like the fat content of cow's milk, depends mainly on heredity. In 1996, the American Psychological Association rated the influence of heredity / upbringing on the level of intelligence as 75/25 **, in 2004, an analysis of several dozen scientific papers in this area issued 85/15. (Wikipedia, English)

Is genius inherited?

No, it is not transmitted. Genius is a unique, one-in-a-million combination of genes. During the formation of germ cells, a recombination of genes occurs, the unique combination is destroyed, and the children of geniuses turn out to be completely ordinary people.

This cruel rule hits hardest of all, again, on livestock breeders - the children of the most beautiful, most delicious and fat pigs are much inferior to their parents. - I wish they could be propagated vegetatively, like strawberries! It is for this (for the absolute preservation of the signs of a brilliant parent) that they are trying to introduce cloning into agricultural practice, but so far something has not been very successful.

Can smart parents have stupid kids?

Maybe why not. The combinations from the previous question are random - they work both for good and for bad. But. From a lot of randomness, statistics are born, and they tell us that smart parents are more likely to have smart children ***.

Looking at your blockhead, you begin to think that statistics have rested on him? - Perhaps at this moment you are the hero of the proverb “they don’t show half the work to a fool.” The child's brain is not yet formed; with age, the child will more and more resemble you in his intellect. (The same American association that gave us 75/25 for teens and older gave it 45/55 for kids.)

Is the older child really smarter than the next?

Everyone, probably, read in fairy tales that the first child in the family is a smart kid, the second is “this way and that”, and the third is a fool. The trick is that this is not only a fairy tale, but also a harsh reality: the fact of a decrease in the level of intelligence in the second and subsequent children is statistically confirmed and is not disputed by anyone now. (For the second children: yes, the older one is indeed smarter, but the difference is small, about three IQ points.)

In 2007, Norwegian scientists tried to explain this phenomenon and measured the intelligence of children in families where the first child died at an early age. From the point of view of biology, the eldest child in such families was the second, from the point of view of education - the first; it turned out that such children were smart, like the first ones. Consequently, the decrease in intelligence with the growth of the child's ordinal number is explained not by biological factors (heredity), but exclusively by upbringing ****.

Is intelligence passed from mother to sons?

This fairy tale in Russian-language sources walks like this: "The genes for intelligence are located on the X chromosome, which the boy receives only from his mother - therefore, the intelligence of the son depends on the mother," while referring to the research of British scientists. This is immediately alarming: it is well known that "British scientists" half the time means "an evil editor ordered us to urgently write a note, and we sucked a little bit out of our finger."

A search on British sites confirmed my fears. Yes, indeed, the boy receives the X chromosome only from the mother (he receives the Y chromosome from the father). The genes responsible for intelligence exist, there are several dozen of them, some of them may be on the X chromosome. Because of this, the child receives slightly more intelligence genes from the mother than from the father - say, 18 from the mother and 16 from the father (the numbers are sucked from the finger).

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* White-skinned people (redheads, freckles) cannot tan like everyone else; people who are receptive to languages, with the same training, will have a better command of French than everyone else.
** Clarification: heritability shows the proportion of genotypic variation in phenotypic variation, i.e. takes the spread of a trait in a population and calculates which share of this spread make up genes, and what - the environment. The statement "the share of heredity in the formation of intelligence is 75%" is a simplification.
*** If parents helluva lot smart, then they need to read the paragraph about genius again.
**** a) parents deal with subsequent children less than with the first; b) the example for the first child is the parent, and for the second, the first child.