The influence of heredity on health. Hereditary factor in preventive medicine Possibilities of age-related psychogenetics for development research

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION

FEDERAL AGENCY FOR EDUCATION

STATE EDUCATIONAL INSTITUTION OF HIGHER PROFESSIONAL EDUCATION

RUSSIAN STATE TRADE AND ECONOMICS UNIVERSITY

IF GOU VPO RGTEU

Department of Commerce, Commodity Science and Product Expertise

Academic discipline: Physical culture

Heredity and its impact on health

Coursework

(last name, first name, patronymic)

4 full-time courses5

by specialty 080401 Commodity research and examination of goods5

(code, name of specialty)

Checked:

(Full name, academic degree, academic title)

Introduction……………………………………………………………………………………….....3

Heredity………………………………………………………………………………..5

Hereditary diseases……………………………………………………………..7

Prevention and treatment of hereditary diseases…………………………….....11

Social and legal aspect of the prevention of certain hereditary

diseases and congenital malformations in humans………………………...14

Conclusion………………………………………………………………………………........17

Bibliography……………………………………………………….18

Introduction

Physical and mental health must be considered dynamically, namely as a process that changes throughout a person’s life. Health largely depends on heredity and age-related changes that occur in the human body as it develops. The body's ability to resist the effects of harmful factors is determined by the genetic characteristics of adaptive mechanisms and the nature of their changes. According to modern concepts, the period of early development (up to 5-8 years) plays a large role in the formation of adaptation mechanisms (approximately 50%). The potential ability to resist harmful factors formed at this stage is realized and constantly improved. But these are only inclinations that need to be developed.

Let's say a child was born with a family history, i.e. he has a damaged mutant gene, which, circulating in the family even before the time of his birth, marked his hereditary properties - genotype. Does this mean that the child will definitely get sick? Is this fatal? It turns out not. This only means that he has a predisposition, the implementation of which requires certain provoking stimuli.

The work of geneticists has proven that under favorable conditions, a damaged gene may not show its aggressiveness. A healthy lifestyle and the overall healthy status of the body can “pacify” its aggressiveness. Unfavorable environmental conditions almost always increase the aggressiveness of pathological genes and can provoke a disease that would not manifest itself under other circumstances.

And if everything is fine with heredity, how will events develop then? If parents are healthy and they have a healthy child, does this mean that he will be healthy throughout his life?

Not at all, since you can inherit good health from your parents and significantly worsen it over the course of a few years. And at the same time, you can be born with poor health, but with effort you can strengthen it.

Thus, the level of health of an individual depends on the genetic “background”, the stage of the life cycle, the adaptive abilities of the organism, the degree of its activity, as well as the cumulative influence of external (including social) environmental factors.

Heredity

Heredity refers to the reproduction in descendants of biological similarities with their parents.

Heredity is a person’s genetic program that determines his genotype.

Hereditary programs of human development include deterministic and variable parts that determine the general things that make a person human, and the special things that make people so different from each other.

The deterministic part of the hereditary program ensures, first of all, the continuation of the human race, as well as the specific inclinations of a person as a representative of the human race, including the inclinations of speech, upright walking, labor activity, and thinking.

External characteristics are passed on from parents to children: body features, constitution, hair, eye and skin color.

The combination of various proteins in the body is strictly genetically programmed, blood groups and the Rh factor are determined.

Blood diseases (hemophilia), diabetes mellitus, and some endocrine disorders—dwarfism—are hereditary.

Hereditary properties also include features of the nervous system, which determine the character and characteristics of the course of mental processes.

The inclinations for various types of activities are inherited. Every child by nature has four groups of inclinations: intellectual, artistic and social. Inclinations are a natural prerequisite for the development of abilities. A few words need to be said about intellectual (cognitive, educational) inclinations. All normal people naturally receive high potential for the development of their mental and cognitive powers. The existing differences in the types of higher nervous activity only change the course of thought processes, but do not predetermine the quality and level of intellectual activity itself. But teachers and psychologists admit that there may be heredity unfavorable for the development of intellectual abilities. Negative predispositions are created, for example, by sluggish brain cells in children of alcoholics, disrupted genetic structures in drug addicts, and hereditary mental illnesses.

Hereditary diseases

All hereditary diseases caused by the presence of one pathological gene are inherited in accordance with Mendel's laws. The occurrence of hereditary diseases is caused by disturbances in the process of storage, transmission and implementation of hereditary information. The key role of hereditary factors in the occurrence of a pathological gene leading to disease is confirmed by the very high frequency of a number of diseases in some families compared to the general population.

Hereditary diseases are diseases transmitted to offspring, caused by changes in hereditary information - gene, chromosomal and genomic mutations. The terms “hereditary diseases” and “congenital diseases” are not synonymous. Congenital diseases are those that are detected from birth; they can be associated with both hereditary and exogenous factors. For example, developmental defects can occur not only due to genetic disorders, but also as a result of infectious agents affecting the embryo. factors, ionizing radiation, chemical compounds, medicines. Hereditary diseases are not always congenital, since many of them do not appear immediately after birth, but several years, sometimes decades later. The term “family diseases” should also not be used as a synonym for the term “hereditary diseases”, since the latter can be caused not only by hereditary factors, but also by living conditions or professional traditions of the family.

About 3,000 hereditary diseases and syndromes are known, which determine a fairly significant “genetic load” of humanity. Hereditary diseases are divided into three main groups:

Monogenic, caused by a defect in one gene;

Polygenic (multifactorial), associated with disruption of the interaction of several genes and environmental factors;

Chromosomal, resulting from changes in the number or structure of chromosomes.

Monogenic diseases are most often caused by mutations of structural genes. Based on the type of inheritance, monogenic diseases are divided into autosomal dominant, autosomal recessive and sex-linked. The autosomal dominant type is inherited mainly for diseases that are based on a violation of the synthesis of structural proteins or proteins that perform specific functions (for example, hemoglobin). These include some hereditary kidney diseases, Marfan syndrome, hemochromatosis, some types of jaundice, neurofibromatosis, familial myoplegia, thalassemia, etc.

With an autosomal recessive type of inheritance, the mutant gene appears only in the homozygous state, when the child receives one recessive gene from the father and the second from the mother. The probability of having a sick child is 25%. The autosomal recessive type of inheritance is most typical for metabolic diseases in which the function of one or more enzymes is impaired.

Recessive inheritance linked to the X chromosome is that the effect of the mutant gene is manifested only with the XY set of sex chromosomes, i.e. in boys (girls have the XX sex set). This type of inheritance is characteristic of progressive muscular dystrophy of the Duchenne type, hemophilia A and B, Gunther's disease, etc.

Dominant inheritance linked to the X chromosome means that the effect of a dominant mutant gene is manifested in any set of sex chromosomes (XX, XY, XO, etc.), i.e., regardless of gender. This type of inheritance can be traced in a rickets-like disease - phosphate diabetes.

According to their phenotypic manifestation, monogenic hereditary diseases are divided into metabolic diseases caused by the absence or decrease in the activity of one or more enzymes; diseases associated with impaired synthesis of structural proteins; immunopathology; diseases caused by impaired synthesis of transport proteins; pathology of the blood coagulation system, transport of substances across cell membranes, hormone synthesis, DNA repair. The most extensive and studied group of monogenic hereditary diseases are metabolic diseases (enzymopathies). Impaired synthesis of structural proteins (proteins that perform plastic functions) is a likely cause of diseases such as osteodysplasia and osteogenesis imperfecta. There is evidence of a certain role of these disorders in the pathogenesis of hereditary nephritis-like diseases - Alport syndrome (characterized by hematuria, hearing loss) and familial hematuria. A gene mutation can lead to pathology of the immune system; Gammaglobulinemia is the most severe, especially in combination with thymic aplasia. Violation of the synthesis of hemoglobin, a transport protein in the blood, caused by a gene mutation, underlies the development of sickle cell anemia. There are a number of known mutations in genes that control the synthesis of blood clotting factors. Genetically determined disorders of the synthesis of blood coagulation factors VIII, IX or XI lead, respectively, to the development of hemophilia A, B or C. An example of a disease caused by a hereditary defect in the transport of substances across cell membranes is cystinuria, caused by a violation of the membrane transport of cystine and diaminocarboxylic acids (arginine, lysine and ornithine) in the kidneys and intestines. The disease is inherited in an autosomal recessive manner and is manifested by increased excretion of cystine in the urine, the development of nephrolithiasis and interstitial nephritis. Diseases associated with a genetic defect in hormone synthesis include hereditary hypothyroidism, caused by impaired synthesis of thyroid hormones. Diseases based on insufficiency of DNA repair mechanisms (restoration of its altered molecule) are being studied. Impaired DNA repair has been established in xeroderma pigmentosum, Fanconi anemia, systemic lupus erythematosus and some other diseases.

Polygenic (multifactorial) diseases, or diseases with a hereditary predisposition, are caused by the interaction of several genes (polygenic systems) and environmental factors. These diseases include gout, some forms of diabetes mellitus, constitutional exogenous obesity, hypertension, many chronic kidney diseases, liver diseases, allergic diseases, etc. Polygenic diseases are observed in approximately 20% of the population; their pathogenesis has not been sufficiently studied. It is assumed that they more often appear under constant exposure to unfavorable environmental factors (poor nutrition, overwork, etc.). Deviations from normal variants of the structure of structural, protective and enzymatic proteins can determine the existence of diathesis in children.

Chromosomal diseases are caused by genomic (changes in the total number of chromosomes) and chromosomal (structural rearrangement of chromosomes) mutations. If they occur in germ cells, then the changes are transmitted to all cells of the body - so-called forms of chromosomal diseases develop. In cases where the mutation arose in the early stages of fragmentation of the embryo, abnormalities in the number or structure of chromosomes will be observed only in part of the cells of the body, and the disease will manifest itself in an incomplete, or mosaic, form.

The clinical classification of hereditary diseases is based on the organ and system principle and does not differ from the classification of acquired diseases. According to this classification, hereditary diseases of the nervous and endocrine systems, lungs, cardiovascular system, liver, gastrointestinal tract, kidneys, blood system, skin, ear, nose, eyes, etc. are distinguished. This classification is conditional, because in most Hereditary diseases involve several organs in the pathological process or systemic tissue damage is observed.

Prevention and treatment of hereditary diseases

Due to insufficient knowledge of the pathogenetic mechanisms of many hereditary diseases, and consequently the low effectiveness of their treatment, preventing the birth of patients with pathology is of particular importance.

Of primary importance is the exclusion of mutagenic factors, primarily radiation and chemical factors, including the influence of pharmacological drugs. It is extremely important to lead a healthy lifestyle in the broad sense of the word: regularly engage in physical education and sports, eat rationally, and eliminate negative factors such as smoking, drinking alcohol, drugs, and toxic substances. After all, many of them have mutagenic properties.

Prevention of hereditary diseases includes a whole range of measures both to protect the human genetic fund by preventing the impact of chemical and physical mutagens on the genetic apparatus, and to prevent the birth of a fetus that has a defective gene that determines a particular hereditary disease.

The second task is especially difficult. To make a conclusion about the likelihood of having a sick child in a given married couple, you should know the genotypes of the parents well. If one of the spouses suffers from one of the dominant hereditary diseases, the risk of having a sick child in this family is 50%. If phenotypically healthy parents give birth to a child with a recessive hereditary disease, the risk of having a sick child again is 25%. This is a very high degree of risk, so further childbearing in such families is undesirable.

The issue is complicated by the fact that not all diseases appear in childhood. Some begin in adulthood, the childbearing period of life, such as Huntington's chorea. Therefore, this subject, even before the diagnosis of the disease, could have children, not suspecting that among them there might subsequently be patients. Therefore, even before marriage, it is necessary to know for sure whether a given subject is a carrier of a pathological gene. This is established by studying the pedigrees of married couples, a detailed examination of sick family members to exclude phenocopies, as well as clinical, biochemical and electrophysiological studies. It is necessary to take into account the critical periods during which a particular disease manifests itself, as well as the penetrance of a particular pathological gene. To answer all these questions, knowledge of clinical genetics is needed.

Basic principles of treatment: exclusion or limitation of products, the transformation of which in the body in the absence of the necessary enzyme leads to a pathological condition; replacement therapy for an enzyme deficient in the body or a normal end product of a distorted reaction; induction of deficient enzymes. Great importance is attached to the factor of timeliness of therapy. Therapy should begin before the patient develops pronounced disorders in cases where the patient is still born phenotypically normal. Some biochemical defects may be partially compensated with age or as a result of intervention. In the future, great hopes are placed on genetic engineering, which means targeted intervention in the structure and functioning of the genetic apparatus, removing or correcting mutant genes, replacing them with normal ones.

Let's consider treatment methods:

The first method is diet therapy: excluding or adding certain substances to the diet. An example would be diets: for galactosemia, for phenylketonuria, for glycogenosis, etc.

The second method is the replacement of substances not synthesized in the body, the so-called replacement therapy. In diabetes mellitus, insulin is used. Other examples of replacement therapy are known: administration of antihemophilic globulin for hemophilia, gamma globulin for immunodeficiency states, etc.

The third method is mediometosis, the main task of which is to influence the mechanisms of enzyme synthesis. For example, the administration of barbiturates for Crigler-Nayar disease promotes the induction of the synthesis of the enzyme glucoronyl transferase. Vitamin B6 activates the enzyme cystathionine synthetase and has a therapeutic effect in homocystinuria.

The fourth method is to avoid taking medications, such as barbiturates for porphyria, sulfonamides for glucose-6-phosphate dehydrogenase.

The fifth method is surgical treatment. First of all, this applies to new methods of plastic and reconstructive surgery (cleft lip and palate, various bone defects and deformities).

Social and legal aspect of the prevention of certain hereditary diseases and congenital malformations in humans

State policy in the field of prevention of certain hereditary diseases and congenital malformations in humans is an integral part of the state policy in the field of protecting the health of citizens and is aimed at the prevention, timely detection, diagnosis and treatment of phenylketonuria, congenital hypothyroidism, adrenogenital syndrome and congenital malformations of the fetus in pregnant women .

State policy in the field of prevention of hereditary diseases and congenital malformations in humans specified in this law is based on the principles of protecting public health established by law.

In the field of prevention of hereditary diseases and congenital malformations in humans, the state guarantees:

a) accessibility for citizens to diagnose phenylketonuria, congenital hypothyroidism, adrenogenital syndrome, congenital malformations of the fetus in pregnant women;

b) free carrying out of the specified diagnostics in organizations of the state and municipal healthcare systems;

c) development, financing and implementation of targeted programs for organizing medical and genetic assistance to the population;

d) control of the quality, effectiveness and safety of preventive, therapeutic and diagnostic care;

e) support for scientific research in the development of new methods for the prevention, diagnosis and treatment of hereditary diseases and congenital malformations in humans;

f) inclusion of issues of prevention of hereditary diseases and congenital malformations in humans into state educational standards for the training of medical workers.

When implementing the prevention of hereditary diseases and congenital malformations in humans specified in this law, citizens have the right to:

a) receiving timely, complete and objective information from medical workers about the need for preventive, therapeutic and diagnostic care, and the consequences of refusing it;

b) receiving preventive care in order to prevent hereditary diseases specified in this law in offspring and the birth of children with congenital malformations;

c) keeping confidential information about the state of health, diagnosis and other information obtained during his examination and treatment;

d) free medical examinations and examinations in state and municipal institutions, health care organizations;

e) free drug provision for phenylketonuria.

2. Citizens are obliged:

a) take care and be responsible for their health, as well as the health of their offspring;

b) if there are hereditary diseases in the clan or family that lead to disability and mortality, promptly contact the medical genetic service;

Responsibilities of medical workers

Medical workers are required to:

a) observe professional ethics;

b) keep confidential information about the presence of hereditary diseases in the patient;

c) carry out activities to diagnose, identify, treat phenylketonuria, congenital hypothyroidism, adrenogenital syndrome in newborn children, medical examination of newborns, as well as to diagnose congenital malformations of the fetus in pregnant women.

Conclusion

The pattern of inheritance of traits such as weight, height, blood pressure, resistance or predisposition to various diseases is determined by the complex interaction of genes involved in their formation. At the same time, the development of these characteristics largely depends on the influence and influence of the environment.

The manifestation of heredity before the age of self-awareness occurs as if automatically, completely under the influence of the environment provided by the parents. From the moment of self-awareness, a person acquires the ability to influence the course of his own development, mental and motor activity. A person’s heredity cannot be considered separately from the integrity of his physical essence, therefore the use of physical education to one degree or another undoubtedly has an impact on maintaining human health. The only question is how to determine whether the use of physical education means is sufficient so as not to cause harm. Let us recall the basic means of physical culture. This includes hygiene, hardening procedures and physical exercise. It must be remembered that hygiene is not only the key to health and vigor, but also a necessary condition for preventing injuries and obtaining maximum benefit from each training session.
If physical exercises are structured wisely, loads increase gradually, rest intervals ensure normal and timely restoration of strength and energy, then they cannot be the cause of illnesses and injuries. Only with the wrong training regime and methodology, the use of excessive loads, training in a painful state or other violations of the regime (combinations of great physical and mental stress, alcohol and drug use, sleep disturbances, diet, etc.) can various disorders occur, accompanied by decreased performance, which negatively affects human health.

Bibliography

1) N.P. Sokolov. “Hereditary human diseases.” Publication: Moscow, “Medicine”, 1965

2) “Great Soviet Encyclopedia”, 2, 16, 17 volumes. Editor-in-Chief A.M. Prokhorov. Edition: Moscow Publisher: “Soviet Encyclopedia”, 1974.

3) Popov S.V. Valueology at school and at home (On the physical well-being of schoolchildren). – SPb.: SOYUZ, 2007. – 256 p.

4) Bochkov N.P. Human genetics (Heredity and pathology) - M., 1978

5) Ginter A.V. Hereditary diseases in human populations. – M.: Medicine, 2002.

6) Kozlova S.I. Hereditary syndromes and medical genetic counseling - M., 1996

Introduction

Physical development

Conclusion

References

Introduction

A newborn carries within himself a complex of genes not only of his parents, but also of their distant ancestors, that is, he has his own, uniquely rich hereditary fund or a hereditarily predetermined biological program, thanks to which his individual qualities arise and develop. This program is naturally and harmoniously implemented if, on the one hand, the biological processes are based on sufficiently high-quality hereditary factors, and on the other, the external environment provides the growing organism with everything necessary for the implementation of the hereditary principle.

Skills and properties acquired during life are not inherited, science has not identified any special genes for giftedness, however, every born child has a huge arsenal of inclinations, the early development and formation of which depends on the social structure of society, on the conditions of upbringing and education, the cares and efforts of parents and the desires of the smallest person.

Young people getting married should remember that not only external signs and many biochemical characteristics of the body (metabolism, blood groups, etc.), but also some diseases or predisposition to painful conditions are inherited. Therefore, each person needs to have a general understanding of heredity, know his or her pedigree (health status of relatives, their external features and talents, life expectancy, etc.), have an idea of ​​the influence of harmful factors (in particular alcohol and smoking) on ​​the development of the intrauterine fetus. All this information can be used for early diagnosis and treatment of hereditary diseases, prevention of congenital malformations.

According to modern scientific data, the chromosomes of the nuclear substance are giant polymer molecules consisting of strands of nucleic acids and a small amount of protein. Each pair of chromosomes has a specific set of genes that control the manifestation of a particular trait.

Child growth is a programmed process of increasing body length and weight, which occurs in parallel with its development and the formation of functional systems. During certain periods of a child’s development, organs and physiological systems undergo structural and functional restructuring; young ones are replaced by more mature tissue elements, proteins, enzymes (embryonic, childhood, adult type).

The genetic program ensures the entire life cycle of individual development, including the sequence of switching and depression of genes that control the change in periods of development in the appropriate conditions of the child’s life. Due to the changing mutual influence of gene and neuroendocrine regulation, each period of child development is characterized by special rates of physical growth, age-related physiological and behavioral reactions.

Inheritance of parental characteristics

The units of heredity - genes - are located on the chromosomes in a strictly defined order, and since a person’s chromosomes are paired, each individual has 2 copies of the gene: the gene on the chromosome received from the mother, and the gene on the chromosome received from the father. If both genes are the same, the individual is said to be “homozygous”; if they are different, the individual is said to be “heterozygous”. Genes that influence the manifestation of a particular trait are located in identical regions (loci) of homologous chromosomes and are called alleles, or alleles. In the heterozygous state, one of the allelic genes is dominant (predominant), the other is recessive. In terms of eye color, brown is dominant and blue is recessive. A recessive trait in the body is in a latent state and can only appear if the gene for this trait is both on the chromosome from the father and on an identical chromosome from the mother. This nature of gene manifestation also predetermines the different mechanisms of manifestation of hereditary diseases, among which there are dominantly and recessively inherited, as well as sex-linked.

To establish whether a particular trait in a person is dominant or recessive, a genealogical research method (pedigree method) helps a doctor, anthropologist or geneticist. A pedigree is a diagram in which several generations of one family are marked with symbols. In this case, women are designated by a circle, men by a square. The characteristic or disease being studied is indicated by a specific letter in the middle of a circle or square, or is depicted as shaded. Parents and their brothers and sisters are located on the same line, children are also located horizontally, but below their parents, and their grandparents are above their parents. Generation numbers are counted from top to bottom by seniority.

When a trait is dominantly inherited, it can be found in one or both parents, as well as in a grandparent. With recessive inheritance, a trait can be detected in only one generation in 25% of its members. A dominant trait in a pedigree diagram clearly appears vertically, while a recessive trait appears only horizontally. There are signs observed in individuals of a certain gender. This means that the gene encoding such a trait is located on one of the sex chromosomes. If such a gene is localized on the X chromosome, then this trait will be observed only in boys, since in girls another identical X chromosome may carry the gene for this trait with a different characteristic. In women, the trait controlled by the X - recessive gene does not appear, but is in a latent state, and they pass it on to half of their sons. Traits encoded on the Y chromosome are inherited only by boys.

The influence of heredity on the mental health of children

The mental development of a child is a complex process that is jointly influenced by the child’s heredity, family climate and upbringing, external environment, as well as a large number of social and biological factors.

There are two scientific directions that study the influence of genetic factors on humans. One of them is aimed at identifying the quantitative contribution of the influence of heredity on the occurrence of the disease, the other is engaged in the search and identification of genes responsible for the occurrence of mental disorders.

To obtain a quantitative assessment of the role of heredity in the development of the disease, families are studied in which the disease under study is often encountered (accumulated). Also, to obtain a quantitative assessment, twin pairs are examined: it is determined how often both twins suffer from mental illness (in this way the percentage of the disease coincidence is determined - concordance), and the difference in this indicator is calculated in identical and multizygotic twins. An effective, although somewhat complex, approach is to study adopted children with mental disabilities and their biological and adoptive parents. This approach allows us to distinguish between the contribution of genetic factors and factors of the separated (intrafamily environment) in the development of the disorder under study.

As a result of applying the approaches described above, scientists can estimate the degree of heritability of a particular disease and calculate the relative risk of its occurrence in the patient’s relatives and his descendants.

Heritability or heritability coefficient is an indicator that reflects the contribution of genetic factors to the variability of the trait being studied. Obviously, it can be assessed by studying pairs of blood relatives, i.e. people who have common genes. A good example of estimating heritability is the study of separated twins. Since such twins were raised in different families, any similarity between them in psychological, emotional and behavioral characteristics can be considered the influence of genetic factors, the quantitative expression of which is the heritability coefficient. We emphasize that heritability cannot be identified with genetic predisposition, which is assessed using other indicators, using, for example, the relative risk value.

To identify genes associated with mental disorder, scientists study isolated social communities in which the disorder accumulates. For example, a number of studies of this kind were conducted among residents of the Pacific Islands, as well as in religious communities closed from the outside world. The advantage of such studies is the ability to establish a common ancestor and trace the transmission of the disease from generation to generation. As a result, scientists are able to determine the region of the chromosome within which there is a gene associated (linked) with the disease of interest to the researcher.

Another research method is to select a gene, a disorder in the structure of which can presumably cause the development of a disease (such a gene is called a “candidate gene”), and study how its polymorphism is related to the development of the disease under study. It is known that each gene can be represented in many forms; they are called polymorphic variants of the gene, and the phenomenon itself is designated by the term molecular genetic polymorphism. Polymorphism is caused by changes in the nucleotide sequence in the DNA of a gene, represented by various variants. This may be the replacement of one nucleotide with another, or the removal of a nucleotide sequence (deletion), or a change in the number of repeating nucleotide sequences. Such changes may not affect the activity (expression) of the gene, i.e. not have any consequences for the body associated with changes in biochemical activity. In other cases, nucleotide substitutions or changes in the number of their repeating sequences may affect the synthesis of the corresponding enzyme, and then differences between people with different polymorphic variants of the gene will appear at the biochemical level. As a rule, these differences do not cause the development of any diseases. But, as will be shown below using the example of the enzyme monoamine oxidase (MAO), the activity of the enzyme may be associated with certain mental characteristics.

The range of mental manifestations is quite wide. Mentally normal people differ from each other in various psychological characteristics. At the same time, we can say with confidence that in approximately half of healthy people, the severity of certain psychological characteristics can reach an intermediate state between the norm and a mental disorder (this state in medicine is called the “level of accentuation”). Accentuation is a kind of sharpening of individual emotional and behavioral traits in a person, which, however, does not reach the level of a personality disorder (psychopathy). The line between accentuation and psychopathy is very blurred, so doctors, when diagnosing a patient with a personality disorder, focus on the possibilities for adaptation of a person with such disorders in society. To illustrate the difference between a healthy person and a person with a mental disorder, let's compare people with a paranoid personality type and paranoid psychopaths. Paranoid individuals are people who are characterized by willfulness, lack of a sense of humor, irritability, excessive conscientiousness, and intolerance to injustice. In paranoid personality disorder, the main symptoms of the disease are: constant dissatisfaction with something, suspicion, a militant and scrupulous attitude towards issues of individual rights, a tendency to experience one’s increased significance, and a tendency to have a unique interpretation of events. Almost all of us have encountered similar people in our lives and can remember the extent to which others may tolerate or reject their behavior.

Accentuation of mental manifestations is followed by so-called borderline disorders, which include neuroses, psychogenic depression, and personality disorders (psychopathy). Endogenous (i.e., caused by the influence of internal factors) mental illnesses close this spectrum of diseases, the most common of which are schizophrenia and manic-depressive psychosis.

In addition to the deviations listed above, children may suffer from diseases that arise due to various disorders in the maturation of mental functions (medics call such disorders non-adaptive or dysontogenetic forms of development). These disorders lead to inadequate intellectual and emotional development of the child, which can be expressed in various manifestations of mental retardation, hyperactivity, criminogenic behavior, attention deficit (increased distractibility), autism.

Let's consider what role genetic factors play in all of the above cases and what is known about the genes that may be associated with human psychological characteristics, as well as the development of mental illnesses.

Psychological characteristics of a person

The personality and psyche of any person is a unique combination of various properties that are formed under the influence of many factors, among which heredity does not always play a leading role. Nevertheless, scientists all over the world have long been trying to answer the question: exactly what properties of a person’s personality are determined by heredity, and to what extent external factors can overcome genetic ones in the formation of a person’s psychological make-up.

In the 20th century, a new branch of science emerged and developed - psychogenetics (in Western science it is called behavioral genetics), and the study of the genetic component of the main mental illnesses - schizophrenia and manic-depressive psychosis - began. At the end of the 80s of the last century, the first works devoted to molecular genetic studies of schizophrenia appeared, and in 1996, scientists for the first time managed to discover genes that determine human temperament.

According to modern scientific research, genetic factors play a significant role in the formation of the psychological properties of a person’s personality. Thus, scientists believe that a person inherits the main psychological traits from his parents by 40-60%, and intellectual abilities are inherited by 60-80%. A more detailed idea of ​​the heritability of intelligence is given in the article by M.V. Alfimova “The influence of genetic heredity on a child’s behavior, changes in influence with age, the influence of heredity on behavior.”

Currently, scientists around the world are actively studying the molecular genetic basis of human behavior, and are also searching for genes associated with the development of mental illnesses. The strategy for searching for such genes is based on the use of the properties of molecular genetic polymorphism, which was previously discussed, as well as on the psychobiological model, which was proposed by the famous American psychologist R. Cloninger. According to this model, the main traits of temperament are closely related to certain biochemical processes occurring in the human brain.

For example, such a trait of a person’s temperament as the desire to search for new sensations, the desire for risk, called by the author “the search for novelty,” is caused by the activity of the dopamine system of the brain, while the serotonin system of the brain is responsible for the occurrence of reactions of fear, anxiety in certain situations and the corresponding The trait is called "harm avoidance."

Dopamine and serotonin are substances that play an important role in transmitting signals along the neural networks of the brain. In other words, these substances are responsible for the occurrence of certain reactions in a person to a certain situation: for example, they aggravate or dull the sense of danger. Scientists are studying the effects of these substances on the human psyche in order to determine how much the ratio of dopamine and serotonin determines a person’s temperament.

When studying the gene responsible for the transfer of serotonin, scientists also found that changes in its structure can affect the human psyche. It turned out that the activity of this gene is determined by the number of nucleotide repeats in its structure, which ultimately affects the level of serotonin entry into the brain. Two alleles of this gene have been found, designated long and short. When studying temperament in carriers of different alleles, it was found that carriers of the short allele are more anxious people compared to carriers of the long allele. It is known that any gene has two alleles, one received from each parent. A person who is a carrier of a gene with two short alleles will be quite different in his psychological qualities from a carrier of a gene with two long alleles. The temperament of such people will vary greatly: it has been proven that, on average, carriers of the two long alleles are less anxious, more aggressive and have greater severity of schizoid traits.

Polymorphism of another gene (monoamine oxidase A (MAOA) gene), which also affects serotonin metabolism in the human brain, is directly related to such temperamental characteristics as aggressiveness, hostility and impulsivity. Geneticists have discovered several polymorphic variants of this gene, varying in length, which are designated as 1, 2, 3, 4 depending on its length. Alleles of the second and third gene are characterized by an increase in the activity of the corresponding enzyme, and alleles 1 and 4 are characterized by a decrease, which indicates the existence of a certain allele length that is optimal for regulating the activity of the serotonin enzyme.

To obtain data on the extent to which the polymorphism of this gene affects the human psyche, a unique study was conducted. Groups of male children - owners of a certain form of the MAOA gene - were studied. They were observed from birth to adulthood. Geneticists studied children who grew up in dysfunctional families in order to determine why some of them, with improper upbringing, commit antisocial acts, while others do not. It turned out that carriers of a genetic variant associated with high activity of the serotonin enzyme are generally not prone to antisocial behavior, even if they grew up in dysfunctional families.

Scientists believe that at least 10-15 genes are responsible for the emergence of a particular psychological trait, while the formation of a mental disorder (or a stable temperamental trait, for example, aggressiveness) is possible only if a number of genetic changes occur in a person.

Mental development disorders

One of the manifestations of mental development disorders in a child, which may be caused by genetic factors, is learning disability. The influence of genetics has been studied most thoroughly for one form of dyslexia, which is associated with a specific reading disability, in particular, the inability to match written and spoken words. This form of dyslexia can be inherited, and an active search is currently underway for the gene responsible for the occurrence of this disorder. There is now evidence that one region of chromosome 6 may be associated with this form of dyslexia.

A disease such as attention deficit hyperactivity disorder (ADHD), diagnosed in 6-10% of children, is also caused by genetic changes. Manifestations of this syndrome are motor restlessness, easy distractibility, and impulsive behavior of the child. This disorder most often occurs in the case of a child’s genetic predisposition: thus, according to researchers, the heritability of ADHD ranges from 60 to 80%. A study of adopted children suffering from this syndrome showed that their biological relatives had it more often than their adoptive parents. It should be noted that ADHD is often combined with other mental disorders, for example, depression, antisocial behavior, and the above-mentioned dyslexia, which allows us to draw conclusions about the presence of common genetic bases for these disorders.

Physical development

The physical development of a child is understood as a set of morphological and functional characteristics of the body in their interrelation. The intensive processes of growth and maturation of the child’s body determine its special sensitivity to environmental conditions. The physical development of children is noticeably affected by climate, living conditions, daily routine, nutritional patterns, as well as previous diseases. The rate of physical development is also influenced by hereditary factors, type of constitution, metabolic rate, endocrine background of the body, activity of blood enzymes and secretions of the digestive glands.

In this regard, the level of physical development of children is considered to be a reliable indicator of their health. When assessing the physical development of children, the following indicators are taken into account:

1. Morphological indicators: body length and weight, chest circumference, and in children under three years of age - head circumference.

2. Functional indicators: vital capacity of the lungs, muscle strength of the hands, etc.

3. Development of muscles and muscle tone, state of posture, musculoskeletal system, development of the subcutaneous fat layer, tissue turgor.

It is believed that there are more than 100 genes that regulate the rate and limit of human growth, but direct evidence of their role is difficult to obtain. The influence of heredity in general affects the physical development, especially the growth, of a child after 5 years of life. There are two periods when the correlation between the heights of parents and children is most significant. This is the age from 5 to 8 years, when the action of one group of genes is affected (the first family factor), and the age from 9 to 11 years, when the regulation of growth depends on other genes (the second family factor). Hereditary factors determine the rate and possible limit of a child’s growth under optimal living and upbringing conditions.

Developmental plans determined by genes establish both the direction of change and the final state. The stability of the development path of any characteristic is determined by how deeply the creeds are laid and how well this characteristic is protected from external influences that could lead it astray, and if this happens, then whether the deviation can be eliminated by itself. Thus, the development of some characteristics is so strongly canalized that they achieve a genetically programmed goal under almost any circumstances. However, there is no reason to believe that for each human trait there is a single canalized pathway defined by one or more genes. It is unlikely, for example, that there is a special gene, especially common to all people, that is responsible for the shape and size of hands, posture, gait or speech. It is more plausible that the manifestation of each behavioral and each physical characteristic is determined by many genes, and, therefore, the paths along which development occurs are varied and complex, and each of them has its own movement, organization and directing force. From this point of view, the changes that occur during development are based on many genes controlled by other (regulatory) genes. Therefore, although the general pattern of development may be essentially the same in all people, considerable variation in physical and behavioral characteristics arises during the course of development. A close examination of any pair of newborns immediately reveals that they are not exactly alike. Despite the commonality of external features and behavior - the specific characteristics of a person, there are individual differences in the color, structure and quantity of hair, in the size and shape of ears and fingers, in facial expressions, in the nature of crying and sleep, in irritability.

Conclusion

Based on the presented facts, we can conclude that having information about the presence of mental and physiological diseases in the pedigree of an adopted child will help to anticipate potential difficulties in the child’s development and possibly avoid them.

Although mental and physiological abnormalities are inherited, the development of the disease is no less strongly influenced than genetic factors by the environment in which the child grows up - the level of education, the child’s social environment, school, and especially the influence of parents and the general family climate. Various mental and behavioral disorders in children arise precisely in orphanages and children's homes, which is associated with a lack of attention to children in these institutions. The very fact of living in a family, and not in an institution, has a decisive impact on the mental health of the child.

It should also be realized that molecular genetic tests to identify mental and physical diseases are a matter of the future. If you are offered an analysis at any medical institution, keep in mind that, at best, this will be a determination of polymorphism of genes that may influence the development of mental disorders. At the same time, no scientist can currently say unambiguously what contribution these genes make to the development of the disease.

In conclusion, I would like to digress from the scientific presentation and move to the plane of assessing the problem from the point of view of common everyday sense and the humanitarian positions taken by a person who decides to raise a child. When connecting your life with a child whose heredity is burdened with severe mental illness, first of all you must recognize the existence of a problem and be prepared to solve it.

References

1. “Mental development of children in normal and pathological conditions” Kolominsky Ya.L., Panko E.A., Igumnov S.A. - St. Petersburg: Peter, 2006. - 480 p.

2. M.V. Alfimova “The influence of genetic heredity on a child’s behavior, changes in influence with age, the influence of heredity on behavior” M., 2006.

3. Amonashvili Sh.A. "Unity of Purpose" M.: Education, 2007. - 208 p.

4. Belov V.P. "Pathological development of the child" M., 2005.

5. Volkov L.V. "Children's physical abilities." Kyiv: Health. - 2004.

6. Barshay V.N., Bobkin A.I. "Physical development - Rostov-on-Don, 2007. - 78 p.

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What in human development depends on himself, and what on external conditions and factors? Conditions are a set of reasons that determine development, and a factor is an important compelling reason, including a number of circumstances. What general conditions and factors determine the course and results of the development process?

Mainly by the combined action of three general factors - heredity, environment and upbringing. The basis is formed by the innate, natural characteristics of a person, i.e. heredity, which refers to the transmission of certain qualities and characteristics from parents to children. The carriers of heredity are genes (translated from Greek “gene” means “giving birth”). Modern science has proven that the properties of an organism are encrypted in a kind of gene code that stores and transmits information about the properties of the organism. Genetics has deciphered the hereditary program of human development.

Hereditary programs of human development include deterministic (constant, unchanging) and variable parts, which determine both the general things that make a person human and the special things that make people so different from each other. The deterministic part of the program ensures, first of all, the continuation of the human race, as well as the specific inclinations of a person as a representative of the human race - speech, upright posture, labor activity, thinking. Parents also pass on external characteristics to their children: body features, constitution, hair, eye and skin color. The combination of various proteins, blood groups, and Rh factor in the body is strictly genetically programmed.

Hereditary properties also include features of the nervous system that determine the nature of mental processes. Defects and deficiencies in the nervous activity of parents, including pathological diseases that cause mental disorders (for example, schizophrenia), can be transmitted to offspring. Blood diseases (hemophilia), diabetes mellitus, and some endocrine disorders—dwarfism, for example—are hereditary. Alcoholism and drug addiction of parents have a negative impact on the offspring.

The variable (variant) part of the program ensures the development of systems that help the human body adapt to changing conditions of its existence. Vast unfilled areas of the hereditary program are presented for subsequent education. Each person completes this part of the program independently. With this, nature provides a person with an exceptional opportunity to realize his potential through self-development and self-improvement. Thus, the need for education is inherent in man by nature.

What do children inherit from their parents – ready-made abilities for mental activity or only predispositions, inclinations, potential opportunities for their development? An analysis of the facts accumulated in experimental studies allows us to answer this question unambiguously: it is not abilities that are inherited, but only inclinations. They may then develop or, under unfavorable circumstances, remain unrealized. Everything depends on whether a person will receive the opportunity to transfer hereditary potency into specific abilities, and is determined by circumstances: living conditions, upbringing, the needs of the person and society.

Normal people receive from nature high potential opportunities for the development of their mental and cognitive powers and are capable of almost unlimited spiritual development. Differences in the types of higher nervous activity change only the course of thought processes, but do not predetermine the quality and level of intellectual activity itself. At the same time, educators around the world recognize that heredity may be unfavorable for the development of intellectual abilities. Negative predispositions are created, for example, by sluggish cells of the cerebral cortex in children of alcoholics, disrupted genetic structures in drug addicts, and some mental illnesses. Smoking by parents can lead to lung diseases. That this is indeed the case was confirmed by a recent study conducted by a group of UK medical professionals. After surveying 5,126 pupils from 65 schools in the north of England, they found that 42% of boys with at least one parent smoked and 48% with both parents complained of a frequent cough. Parents and girls suffer no less from this bad habit. Smoking by mothers has a particularly detrimental effect on the health of children.

In addition to general inclinations for intellectual activity, special inclinations for a specific type of activity are also inherited. It has been established that children who possess them achieve higher results and advance in their chosen field of activity at a faster pace. When such inclinations are strongly expressed, they manifest themselves at an early age if a person is provided with the necessary conditions. Special abilities are musical, artistic, mathematical, linguistic, sports and other inclinations.

Austrian teachers F. Hecker and I. Ziegen studied how musical inclinations are transmitted from parents to children. For this purpose, they collected impressive statistics, examining about 5 thousand individuals. Their conclusions are as follows:

If both parents are musical, then among their children (%):

musical – 86,

few musical ones – 6,

not musical at all – 8.

If both parents are not musical, then among their children (%):

musical - 25,

few musical ones - 16,

not musical at all - 59.

If one parent is musical and the other is not, then among their children (%):

musical – 59,

few musical ones - 15,

not musical at all – 26.

Research has been carried out repeatedly on the transfer of mathematical, artistic, literary, technical, and craft skills. The conclusion is always the same: a child is born carrying within himself a predisposition to the qualities that prevail in his parents.

What is the heredity of highly gifted children? This question was asked by the American researcher K. Theremin. He and his assistants examined 180 children selected from 250 thousand US schoolchildren through psychological tests. It turned out that at birth they already had a higher weight than normal, began to walk and talk earlier than usual, and started teething earlier. They were sick less often, and their sleep duration was 30–60 minutes longer. The children showed great initiative for learning and usually taught themselves. 29% of the total number of selected children knew literacy before the age of 5, 5% before the age of 4, and 9 people before the age of 3. 80% of gifted children come from cultured, educated families. Families with poorly trained parents account for only 1–2%. Among the relatives of gifted children there are a large number of writers, scientists, and statesmen.

In the book “The Mentally Gifted Child” Yu.Z. Gilbukh identified the following indicators of general talent:

– extremely early manifestation of high cognitive activity and curiosity;

– speed and accuracy of performing mental operations, due to the stability of attention and working memory;

– development of logical thinking skills;

– richness of active vocabulary, speed and originality of word associations;

– focus on creative completion of tasks, development of thinking and imagination;

– mastery of the basic components of learning ability.

How do highly gifted children get through regular school? Almost all of them “step over” a grade, sometimes after two or three. For example, Ilya Frolov, who became a university student at the age of 14, mastered the fifth grade program in the fourth grade, and immediately moved from the eighth to the tenth. Muscovite Savely Kosenko became a student at Moscow State University at the age of 11. Started reading at the age of two. At the age of three he was fluent in four arithmetic operations. By the age of five I had read all of Jules Verne, and by the age of seven I was writing far from children’s programs on the computer. When it was time for his peers to go to school, he passed exams for five classes as an external student. I completed the school curriculum by the age of ten.

When does a child grow up smarter? American professor A. Zainz proved that the only child in a family who communicates only with adults gains intelligence much faster than one who has brothers and sisters. The youngest child is always inferior in development to the eldest, unless there is a difference of 12 years between them.

Scientists from the Institute of Psychology of the Russian Academy of Sciences have established another pattern. According to their findings, children raised by their parents were more intelligent than those raised by their grandparents. But talented artists and performers often emerge from beloved grandchildren. Psychologists have also established the truth of the old truth about the children of geniuses: the offspring of very smart parents never reach their parents’ heights, and the offspring of very stupid ones always rise above their level.

In addition to the biological, social heredity has a significant impact on human development, thanks to which the newborn actively assimilates the socio-psychological experience of the parents and everyone around him (language, habits, behavioral characteristics, moral qualities, etc.). The question of the inheritance of moral inclinations is especially important. For a long time it was believed that a person is not born either evil or kind, neither generous nor stingy, much less a villain or a criminal, and that children do not inherit the moral qualities of their parents.

Then why do many scientists adhere to the theory of “inherent evil”? And is the proverb that has come down to us from time immemorial true that the apple doesn’t fall far from the tree? Today, an increasing number of scientists and educators are inclined to think that human moral qualities are biologically determined. People are born good or evil, honest or deceitful, nature gives a person pugnacity, aggressiveness, cruelty, greed (M. Montessori, K. Lorenz, E. Fromm, A. Micherlik, etc.).

A person becomes a person only in the process of socialization, i.e. interactions with other people. Outside human society, spiritual, social, and mental development cannot occur. Remember the fairy tale about Mowgli, raised by a pack of wolves, remember how little humanity remains in him, and you will agree that outside human society a person has no chance of becoming an individual.

In addition to heredity, human development is significantly influenced by the environment - the reality in which development occurs, i.e. various external conditions - geographical, social, school, family. Some of them concern all children of a given region (geographical factors), others reflect the characteristics of the environment (say, a city or a village), others are important only for children of a particular social group, and others are related to the general well-being of the people (it is not surprising that wars and years of deprivation always have the most adverse effect primarily on children).

Based on the intensity of contacts, the near and far environments are distinguished. When teachers talk about its influence, they primarily mean the social and home environment. The first refers to the distant environment, the second to the immediate environment: family, relatives, friends. Home (everyday) factors determine the development of a given child, and the level of this development speaks primarily about how his nutrition is established in the family, whether the schedule of activities and rest is observed, whether physical and mental stress is dosed correctly. Sharp deviations from the norm of physical development are a signal for parents and teachers: they are missing something important here, it is necessary to take all measures to improve the child’s health. The concept of “social environment” includes such general characteristics as the social system, the system of production relations, material living conditions, the nature of production and social processes, and some others.

What is the influence of the environment on the formation of a person? Its enormous importance is recognized by educators all over the world. As you know, there is no abstract medium. There is a specific social system, specific living conditions for a person, his family, school, friends. Naturally, a person reaches a higher level of development where the near and distant environment provides him with the most favorable conditions.

The home environment has a huge impact on human development, especially in childhood. The family usually hosts the first years of a person’s life, which are decisive for the formation, development and formation. A child is usually a fairly accurate reflection of the family in which he grows and develops. The family largely determines the range of his interests and needs, views and value orientations. It also provides conditions for the development of natural abilities. Moral and social qualities of an individual are also established in the family.

The current family is going through hard times. The number of divorces, single-parent families, and socially disadvantaged children is growing. The family crisis, according to experts, has become the cause of many negative social phenomena, and above all the root cause of the increase in crime among minors. Teenage crime in Russia is not yet on the decline.

A significant number of offenses in the country are committed by teenagers and young people aged 14–18 years. This means that the influence of the environment is worsening, and along with it, the development results will be worse.

What is more important – environment or heredity? Experts' opinions were divided. The influence of the environment, according to some estimates, can reach 80% of the total influence of all factors. Others believe that 80% of personality development is determined by heredity. The English psychologist D. Shuttleworth (1935) came to the conclusion that:

– 64% of the factors of mental development are due to hereditary influences;

– 16% – to differences in the level of family environment;

– 3% – for differences in raising children in the same family;

– 17% – due to mixed factors (interaction of heredity with environment).

Each person develops in his own way, and everyone has their own share of the influence of heredity and environment. The proportions in which the active causes are intertwined, and what result their interaction will lead to, also depends on many random factors, the actions of which cannot be taken into account or measured.

Thus, the process and results of human development are determined by the joint action of three general factors - heredity, environment and upbringing. It is not abilities that are inherited, but only inclinations. In addition to biological heredity, there is social heredity, thanks to which a newborn person actively assimilates the socio-psychological experience of his parents and everyone around him (language, habits, behavioral characteristics, moral qualities, etc.). Its development, in addition to heredity, is significantly influenced by the environment.

This is one of the factors that cannot be influenced. No diet or regular exercise, even the most excellent, can eliminate the existence of bad heredity, which is expressed in a predisposition to cardiovascular diseases. Certain disorders of the heart can be passed on from generation to generation, remain hidden for many years and suddenly lead to death, as sometimes happens to distance runners. That's why it's important to know your family history of illness to help you understand your risk of having a serious heart attack.

If there have been people in the family who died at an early age from heart disease, it is very important to determine what exactly was the cause of their death. There is no need to worry too much if one of the relatives who died of heart disease at a young age was significantly overweight, smoked a lot and led a predominantly sedentary lifestyle. His early death will not be a “hereditary factor”, since the cause most likely was the so-called external factors that do not affect the descendants if they do not lead the same depressingly incorrect lifestyle. At the same time, if a relative who died early was slim and fit, did not smoke, regularly exercised, and nevertheless died before the age of 50 from a heart disease, then we can talk about the presence of a factor that can be inherited.

Heredity can, to some extent, protect against diseases. Everyone knows many stories about people who were heavy smokers, drank alcohol in unlimited quantities and ate as much as if they did not expect to wait for tomorrow, but died at the age of 95 due to a skiing accident. Indeed, there are many people in whose physique and appearance there is nothing that at first glance could distinguish them from the rest and protect them from the likelihood of cardiovascular diseases. Thus, in the state of Arizona there lives a tribe of Pima Indians, which, it would seem, should be among the first candidates for cardiovascular diseases. They have the largest number of diabetes cases and a very high percentage of those suffering from excessive obesity. Their diet largely consists of what nutritionists call “empty calories.”

But for all that, they have an extremely low content of “bad” cholesterol (low density) and a high content of “good” cholesterol (high density) in the blood. Apparently, this is why the percentage of heart disease among Pima Indians is seven times lower than among other American populations. Only 4-6% of these people under 60 years of age have any abnormalities on the electrocardiogram. This means that we can say that this ethnic group has developed a hereditary protective reaction against cardiovascular diseases. Perhaps this is due to the fact that their ancestors lived in harsh conditions and worked a lot physically.

In some examples, when studying cardiovascular diseases and the influence of heredity, the negative impact of the “Western” lifestyle on representatives of those nationalities who were little predisposed to these dangerous diseases was clearly visible. As soon as these people changed their diet and lifestyle, the percentage of cardiovascular diseases and sudden deaths among them increased significantly.

So, although nothing can be changed if one of your ancestors suffered from cardiovascular disease, it is possible to “correct” so-called external factors, such as diet or lifestyle.

The study of the degree of heritability of various morphofunctional indicators of the human body has shown that the genetic influences on them are extremely diverse. They differ in terms of detection time, degree of impact, and stability of manifestation (Sologub E.B., Taymazov V.A., 2000).

The greatest hereditary influence was found for morphological parameters, the least for physiological parameters and the least for psychological characteristics.(Shvarts V.B., 1991, etc.).

Among morphological characteristics the most significant influences of heredity are on the longitudinal dimensions of the body, smaller ones on volumetric dimensions, and even smaller ones on body composition (Nikityuk B.A., 1991).

As studies have shown (Korobko T.V., Savostyanova E.B., 1974), the value of the heritability coefficient is highest for bone tissue, lower for muscle tissue and lowest for fatty tissue; for the subcutaneous tissue of the female body it is especially small (Table 5.3). With age, environmental influences increase, especially on the fat component (Table 5.4).

Table 5.3

The role of the genetic factor (H) in the development of body components, %

Table 5.4

Age-related changes in genetic influences (H) on body components, %

For functional indicators a significant genetic dependence of many physiological parameters has been identified, including: metabolic characteristics of the body; aerobic and anaerobic capacity; volume and dimensions of the heart, ECG values, systolic and minute blood volume at rest, heart rate during exercise, blood pressure; vital capacity of the lungs (VC) and vital indicator (VC/kg), frequency and depth of breathing, minute volume of breathing, duration of breath holding during inhalation and exhalation, partial pressure of O and CO in alveolar air and blood; cholesterol content in the blood, erythrocyte sedimentation rate, blood groups, immune status, hormonal profile and some others (Table 5.5).

Table 5.5

Indicators of the influence of heredity (H) on some morphofunctional characteristics of the human body (Shvarts V.B., 1972; Tishina V.G., 1976; Kots Ya.M., 1986; Ravich-Shcherbo I.V., 1988; Eysenck G. Yu., 1989; Moskatova A.K., 1992, etc.)

Morphofunctional characteristics	Heritability rate (H)
Body length (height)
Body weight (weight)
Fat fold
Circulating blood volume
Red blood cell and hemoglobin concentration
Leukocyte concentration
Acid-base balance (pH) at rest and during work
Erythrocyte sedimentation rate (ESR)
Phagocytic activity of leukocytes
Absolute level of immunoglobulins
Heart volume
ECG indicators
Duration of P, R waves, R-R intervals
Minute blood volume (l/min)
Stroke blood volume (ml)
Heart rate at rest (bpm)
Heart rate during work (bpm)
Systolic blood pressure at rest and during work
Diastolic blood pressure at rest and during work
Vital capacity of the lungs (VC)
Vital indicator (VC/kg)
Minute volume of breathing at rest
Minute breathing volume during work
Maximum ventilation
Depth of breathing at rest
Respiratory rate at rest
Resting oxygen consumption
Oxygen consumption at work
Maximum oxygen consumption (VO2)
Relative MIC value (ml/min/kg)
Maximum Anaerobic Power (MAP)
Holding your breath while inhaling
Percentage of slow fibers in male muscles
Percentage of slow fibers in women's muscles
Development of conditioned reflexes
Mental performance
Frequency-amplitude indicators of EEG

Many psychological, psychophysiological, neurodynamic, sensorimotor indicators, characteristics of sensory systems are also under pronounced genetic control: most of the amplitude, frequency and index indicators of the EEG (especially alpha rhythm), statistical parameters of mutual transitions of waves on the EEG, speed of information processing (brain bandwidth); motor and sensory functional asymmetry, hemispheric dominance, temperament, intelligence quotient (IQ); sensitivity thresholds of sensory systems; differentiation of color vision and its defects (color blindness), normal and far-sighted refraction, critical frequency of fusion of light flickers, etc.

The general conclusion of all the studies conducted was the conclusion that the more complex a person’s behavioral activity, the less pronounced the influence of the genotype and the greater the role of the environment. For example, for simpler motor skills the genetic factor is more important than for more complex skills (Sologub E.B., Taymazov V.A., 2000).

Most behavioral acts are controlled by a whole complex of genes, but there may be fewer of them. Thus, in animal experiments, only two genes were identified that affect motor skills (cause degenerative changes in motor neurons) (Sendter M. et al, 1996); Four genes have been described that sharply increase aggressive behavior (Tecott L.H., Barondes S.H., 1996).

It turned out that During ontogenesis, the role of the hereditary factor decreases. Thus, long-term longitudinal studies on twins (at the ages of 11, 20-30 and 35-40 years) showed that some characteristics generally lose similarity with age, even in identical twins, i.e. environmental factors are becoming increasingly important. This is due to the fact that as a person enriches himself with life experience and knowledge, the relative role of the genotype in his life activity decreases.

Some have been discovered differences in the inheritance of traits by sex. In men, left-handedness, color blindness, ventricular volume and heart size, a tendency to increase or decrease blood pressure, the synthesis of lipids and cholesterol in the blood, the nature of fingerprints, characteristics of sexual development, the ability to solve digital and abstract problems, and orientation in new situations are more inherited . In women, body height and weight, development and timing of the onset of motor speech, and manifestations of functional symmetry of the cerebral hemispheres are more genetically programmed.

Genetic factors play an important role in deviations from normal human behavior. Thus, among bisexuals and homosexuals, sexual behavior is not only the result of certain living conditions (army, prison, etc.), but also (in approximately 1-6% of the population) heredity. In girls with various genetic anomalies, special boyish behavior has also been described (Tomboyism syndrome; from the English “Tom boy”).

Manifestations mental retardation, weaknesses in spatial perception, low school performance in some cases are caused by defects in the genetic apparatus: in diseases associated with changes in the number of sex chromosomes (for example, XO, XXX, XXY, etc.), in the presence of a “fragile” X chromosome in women (1 :700 cases), etc.

Individuals with the XYY set of sex chromosomes have reduced intelligence and a tendency to aggressive behavior, violence and crime. The share of criminals among them is reliable (p< 0,01) выше (41,7% случаев), чем среди лиц с нормальным набором хромосом - XY (9,3%). Однако, несмотря на многочисленные работы по генетике человека, для окончательного суждения о роли генотипа в жизнедеятельности еще очень мало данных.

Hereditary influences on various physical qualities are heterogeneous. They manifest themselves in varying degrees of genetic dependence and are detected at different stages of ontogenesis.

Fast movements are most subject to genetic control, requiring, first of all, special properties of the nervous system: high lability (the speed of the nerve impulse) and mobility of nervous processes (the ratio of excitation and inhibition and vice versa), as well as the development of anaerobic capabilities of the body and the presence of fast fibers in skeletal muscles.

For various elementary manifestations of the quality of speed, high heritability rates were obtained (Table 5.6). Using twin and genealogical methods, a high dependence on innate properties (H = 0.70-0.90) of indicators of high-speed short-distance running, tapping test, short-term pedaling on a bicycle ergometer at maximum speed, standing long jump and other high-speed tests was confirmed. and speed-strength exercises.

Table 5.6

P influence of heredity (H) on the physical qualities of a person (Moskatova A.K., 1983, etc.)

Indicators	Heritability coefficient (H)
Motor reaction speed
Tapping test
Speed ​​of elementary movements
Sprint speed
Maximum static force
Explosive force
Hand coordination
Joint mobility (flexibility)
Local muscular endurance
General Stamina

At the same time different methodological conditions of surveys, insufficient consideration of population, gender and age differences, lack of uniformity in the tests used lead to a noticeable scatter in the values ​​of indicators among different authors. For example, variations in the heritability coefficient (H 2) of many speed characteristics of motor reactions, according to various researchers, for the tapping test are 0.00-0.87; time of simple motor reaction to visual stimuli -0.22-0.86; reaction time to sound stimuli - 0.00-0.53; frequency of running in place - 0.03-0.24; speed of hand movement -0.43-0.73. Heritability coefficients for speed-strength tests also have noticeable variations: 60 m run -0.45-0.91; long jump - 0.45-0.86; high jump -0.82-0.86; shot put - 0.16-0.71 (Ravich-Shcherbo I.V., 1988).

High genetic determination obtained for the quality of flexibility. Flexibility of the spinal column - 0.7-0.8; mobility of the hip joints - 0.70, mobility of the shoulder joints - 0.91.

To a lesser extent, genetic influences are expressed for indicators of absolute muscle strength. So, for example, the heritability coefficients for dynamometer indicators of strength of the right hand are H = 0.61, for the left hand - H = 0.59, deadlift strength - H = 0.64, and for indicators of simple motor reaction time H = 0.84, complex motor reaction H = 0.80. According to various authors, heritability indicators for muscle strength of the hand flexors range from 0.24-0.71, forearm flexors - 0.42-0.80, trunk extensors - 0.11-0.74, leg extensors - 0. 67-0.78.

The least heritability is found for indicators of endurance to long-term cyclic work and the quality of agility(coordination capabilities and the ability to form new motor acts in unusual conditions).

In other words, the most trainable physical qualities are agility and general endurance, and the least trainable are speed and flexibility. The middle position is occupied by the quality of strength.

This is confirmed by data from N.V. Zimkin (1970) and others about the degree of increase in various physical qualities in the process of long-term sports training. The values ​​of speed quality indicators (in sprint running, 25-50 m swimming) increase by 1.5-2 times; quality of strength during the work of local muscle groups - 3.5-3.7 times; during global work - by 75-150%; quality of endurance - tenfold.

Manifestations of genetic influences on physical qualities depend on:

1. ­ age. More pronounced at a young age (16-24 years) than in adults;
2. ­ work power. The influences increase with increasing power of work;
3. ­ period of ontogenesis. There are different periods for different qualities.

In the process of ontogenesis, as noted above, critical and sensitive periods are distinguished.

Critical and sensitive periods coincide only partially. If critical periods create the morphofunctional basis for the existence of an organism in new conditions of life (for example, during the transition period in an adolescent), then sensitive periods realize these possibilities, ensuring adequate functioning of the body's systems in accordance with new environmental requirements. The moments of their switching on and off during certain periods of ontogenesis are very similar in identical twins, which demonstrates the genetic basis of the regulation of these processes.

Sensitive periods for various qualities appear heterochronically. Although there are individual variations in the timing of their onset, general patterns can still be identified. Thus, the sensitive period for the manifestation of various indicators of the quality of speed occurs at the age of 11-14 years, and by the age of 15 its maximum level is reached, when high sporting achievements are possible. At this level, speed can last up to 35 years, after which the body’s speed properties decrease. A picture close to this is observed in ontogenesis and for the manifestation of the qualities of dexterity and flexibility.

Somewhat later, a sensitive period of strength quality is noted. After relatively small rates of annual increases in strength in preschool and primary school age, a slight slowdown occurs at the age of 11-13 years. Then comes a sensitive period for the development of muscle strength at 14-17 years of age, when the increase in strength during sports training is especially significant. By the age of 18-20 years, boys (girls 1-2 years earlier) reach the maximum manifestation of strength in the main muscle groups, which persists until approximately 45 years. Then muscle strength decreases.

The sensitive period of endurance occurs at approximately 15-20 years, after which its maximum manifestation and record achievements at distances in running, swimming, rowing, cross-country skiing and other sports requiring endurance are observed. General endurance (long-term work of moderate power) persists in human ontogenesis longer than other physical qualities, decreasing after 55 years.

Note. This is associated with the greatest adequacy of long-term dynamic work of low power for older people who are able to perform this kind of exercise without taking into account time for quite a long time.

In the practice of sports, the role of family heredity is known. According to P. Astrand, in 50% of cases, children of outstanding athletes have pronounced athletic abilities. Many brothers and sisters show high results in sports (mother and daughter Deryugins, Znamensky brothers, Press sisters, etc.). If both parents are outstanding athletes, then their children are likely to achieve high results in 70% of cases.

Back in 1933, I. Frischeisen-Kohler showed that indicators of the speed of performing the tapping test have pronounced intrafamily heritability (cited from Ravich-Shcherbo I.V., 1988). If both parents, according to the tapping test, fell into the “fast” group, then among the children of such parents there were significantly more “fast” (56%) than “slow” (only 4%). If both parents turned out to be “slow,” then among the children the “slow” ones predominated (71%), and the rest were “average” (29%).

It turned out that intrafamily similarity depends on the nature of the exercises, the characteristics of the population, and the order of birth of the child in the family. Closer intra-family relationships are inherent in speed, cyclic and speed-strength exercises. A study of archives in English private colleges, where children of selected families traditionally studied, showed a certain similarity in the motor abilities of children and parents at the age of 12. A significant correlation was established for some morphological characteristics and speed-strength exercises: body length (p = 0.50), 50-yard run (p - 0.48), standing long jump (p = 0.78). However, there was no correlation for complex coordination movements, such as throwing a tennis ball and gymnastic exercises.

Many family characteristics of various body functions were studied.

Studies of changes in pulmonary ventilation in response to a lack of oxygen (hypoxia) and excess carbon dioxide (hypercapnia) in adult distance runners showed that the respiratory responses of fit runners and their non-athlete relatives were almost identical. Moreover, they differed significantly from more significant changes in pulmonary ventilation in the control group of people not involved in sports (Scoggin S. N. et al., 1978).

Some contradictory data from an intrafamily study of morphological characteristics of genetics are explained by the influence of population characteristics (Sergienko L.P., 1987).

For example, there are differences in the nature of intrafamilial genetic influences on TD in different populations: in the American population, the highest correlation was found in mother-daughter pairs, then its decrease in mother-son, father-son, father-daughter pairs; in the African population, the decrease in correlation was noted in a different order: from father-son pairs to mother-son, mother-daughter, father-daughter pairs.

G. Eysenck (1989) reported on intrafamily relationships in relation to mental performance (in terms of intelligence quotient - IQ). In terms of the speed of solving intellectual problems, the indicators of adopted children corresponded to the mental abilities of their biological parents, but not their adopted ones. These facts indicated the hereditary nature of these abilities, which are of great importance for the effectiveness of tactical thinking in athletes.

It has been established that the value of intellectual potential is influenced by the order of birth of children in the family. In families with one to three children, intellectual abilities are on average quite high. In large families (four to nine children or more), these abilities decrease with each subsequent child (Belmont L, Marolla F. A., 1973). The natural decrease in mental performance (determined by indicators of perception and processing of information and other tests) did not depend on the social origin of the individuals examined (Fig. 54). It is believed that one of the reasons may be a violation of the full reproductive function in women with age. The birth order of children also influences changes in indicators of responsibility and dominance, which decrease from older to younger boys (Harris K.A., Morrow K.B., 1992).

Researchers They especially highlight the intellectual advantages of first-born children. Statistics show that among the famous, most famous people and outstanding scientists, they make up the majority. When analyzing the composition of hormones in blood taken from the umbilical cord of newborn boys and girls, a predominance of female sex hormones (progesterone and estrogens) was found in first-borns of both sexes compared to younger children, and among boys - a greater amount of male sex hormone (testosterone) in first-borns, than their younger brothers. Next, a hypothesis was put forward about a direct connection between human mental development and the genetically determined content of sex hormones (Brothers D., 1994).

In families formed by close relatives, genetic influences have a negative effect. An analysis of the marriages of cousins ​​and brothers revealed a decrease in mental abilities in their children.

Rice. 54. Intellectual abilities in children in families of three social groups, depending on the order of birth of the child (according to Belmont L, Marolla E, 1973): 1 - mental work group (n = 137823); 2 - physical labor (n = 184334); 3 - farmers (n = 45196).

(The ordinate is the test scale of intellectual abilities: 1.0 - maximum, 6.0 - minimum).

Many morphofunctional characteristics that determine a person’s athletic abilities and are inherited from parents to children are genetically dependent.

Special inheritance type analysis(dominant or recessive) person's athletic ability was carried out by L.P. Sergienko (1993) in 163 families of high-class athletes (15 MS, 120 MS of international class, 28 honored MS - winners and medalists of the Olympic Games, World, European and USSR Championships).

It turned out that most often (66.26%) high achievements were noted in “adjacent” generations: children - parents. In this case, there were no “skips” of generations (as in the case of a recessive type of inheritance). Hence the assumption was made about the dominant type of inheritance.

It was found that parents, brothers and sisters - outstanding athletes - had physical activity significantly higher than the level typical for ordinary people in the population. 48.7% of parents were involved in physical labor or sports, more often fathers (29.71%) than mothers (18.99%); Brothers (79.41%) were more active than sisters (42.05%).

Among male athletes, there was not a single case where the mother was involved in sports, but the father was not. Prominent athletes had many more male relatives than female ones; male relatives had higher sports qualifications than female relatives.

Thus, in male athletes, motor abilities were passed down through the male line.

Among female athletes, athletic abilities were passed down primarily through the female line.

Outstanding athletes were predominantly younger and were born, as a rule, into families with two (44.79%) or three (21.47%) children.

There is a special pattern of family resemblance in the choice of sports specialization. According to L.P. Sergienko (1993), the greatest similarity was found in the choice of wrestling (85.71%), weightlifting (61.11%) and fencing (55.0%); the least preference is for basketball and boxing (29.4%), acrobatics (28.575) and volleyball (22.22%). V.B. Schwartz (1972, 1991) reported high rates of familial heritability in skiing (78%) and sprinting (81%).

For sports selection of children (especially in its first stages), those factors determining the success of sports activities that are most limited by heredity and are conservative in nature become important. This is understandable, since any successful forecast is possible only if it is based on some stable, predictably developing factors. If we take factors that are easily trainable as the basis for the forecast (i.e., they depend on environmental influences), then, given the incomplete formation of the body in childhood, it is almost impossible to carry out the forecast.

Which of the identified factors are the most limited by heredity and can serve as the most reliable indicators in determining athletic fitness?

One of these factors is the constitutional structure of the body, its anthropometric data. Moreover, heredity has the greatest influence on the longitudinal dimensions of the body (length of the body, upper and lower extremities, etc.), less on latitudinal dimensions (width of the pelvis, hips, shoulders) and even less on volumetric dimensions (girth of the wrist, thigh, shin, etc. .).

In table Table 5.7 shows the degree of heritability of a number of basic anthropometric (morphological) characteristics (Shvarts V.B., Khrushchev S.V., 1984).

Table 5.7

Heritability of human morphological characteristics

The slightly lower heritability of transverse (latitudinal) and volumetric dimensions compared to longitudinal ones can be explained by the rather large variability of the fat component. Thus, between the ages of 11 and 18 years, this component, which largely determines body composition, changes by 43.3% (and after 18 - even more), while the fat-free component changes by only 7.9%.

Thus, the most reliable indicators of physique are height and other longitudinal dimensions of the body. In those sports where height is of great importance, this indicator can be used as one of the main ones already at the stage of primary selection, especially since it is possible to predict the length of a child’s body at almost any age, for which you can use the data given in table. 5.8.

Table 5.8

Body length in boys and girls aged 1 to 18 years (in% of the final body length of an adult) (according to Schwartz V.B., Khrushchev S.V., 1984)

Age, years
	boys

Despite the fact that the transverse dimensions of the body are heritable to a somewhat lesser extent, nevertheless, they can also serve as indicators of the appropriateness of practicing a particular sport.

It is also believed that a promising criterion for athletic fitness is the amount of lean, or active, body mass, most simply determined by the size of the skin-fat folds at 10 points of the body using a special device - a calipermeter. The use of this indicator is due to the fact that a person’s ST is largely determined by the presence (ratio) of fat-free and fat components.

Along with the constitution of the body, the most genetically determined characteristics are, as already noted, the basic properties of the nervous system, which largely determine the mental make-up of the individual, his temperament, and character. Inherited from the father or mother, such characteristics of the nervous system as mobility, dynamism and balance practically do not change throughout life. Therefore, in those sports in which one or another property of the nervous system (or a set of properties) is of decisive importance, it can be quite reliable in determining athletic suitability. Unfortunately, in practice these signs are practically not used.

As for personal character traits, they (although based on the type of nervous system), depending on living conditions, the nature and direction of activity, the motivation of this activity, are subject to significant changes, that is, they are quite mobile and therefore at the primary stages of selection when determining athletic suitability cannot be used as main ones.

One of the important factors that determine the success of sports activities and are most widely used in the sports selection of applicants to the Youth Sports School is physical readiness, which is manifested, as already mentioned, in the level of development of conditioned physical qualities. Therefore, it is extremely important to consider whether the upper threshold for the development of these qualities (endurance, speed, strength, flexibility) is inherited or whether the possibilities for their improvement are limitless.

Endurance is a physical quality that is of great importance not only in cyclic, but also in many other sports; to a certain extent basic for the development of other physical abilities.

There is still a widespread opinion that if, for example, natural inclinations are needed to develop speed, then endurance can be developed in any person; only systematic targeted training is needed. Experimental data shows that this is not the case. It turns out that high results at distance races can be achieved only if you have a certain heredity. It has been established that maximum oxygen consumption (MOC), as the main criterion for assessing aerobic endurance, is within the limits determined by the individual genotype. The increase in VO2 max during the most advanced training does not exceed 20-30% of the initial level. Thus, MOC (as an integral indicator of the performance of all systems that provide the body with oxygen) is one of the main features that determine the choice of sports that require maximum aerobic endurance. The relative value of MOC in children changes slightly, especially among young athletes (Fig. 55) (Shvarts V.B., Khrushchev S.V., 1984).

Rice. 55. Age dynamics of VO2 max (ml/min/kg) in athletes aged 10 to 18 years

Therefore, this indicator can be so reliable when choosing a sports specialization.

Another genetically determined indicator of the potential for development of aerobic endurance is muscle fiber composition. It has been proven that human muscles contain so-called “fast” and “slow” fibers (the names of the fibers are due to the difference in the time of their contraction). An athlete (depending on the predominance of one or another) is able to achieve success in “fast” or “slow” sports. Training does not change this ratio. Therefore, muscle composition can be a reliable sign when determining the athletic suitability of an already beginning athlete (in highly qualified stayers, the number of “slow” fibers reaches 85-90%, “fast” fibers - only 10-15%).

It should be noted that there is a direct connection between MIC and “slow” fibers: the higher the level of MIC, the more “slow” fibers in human muscles (Fig. 56) (Shvarts V.B., Khrushchev SV., 1984).

Considering that determining muscle composition requires rather complex laboratory equipment and appropriate qualifications of a specialist, in practice the MOC indicator is most widely used.

Rice. 56. Composition of the muscles of “slow” fibers (left) and VO2max (ml/min/kg) - on the right in representatives of various sports

With MPC, a fairly reliable indicator of aerobic endurance is physical performance, determined by the PWC (physical performance) test. Determination of physical performance using this test is based on two well-known facts from the physiology of muscle activity:

1. increased heart rate is directly proportional to the intensity (power) of the work performed;
2. the degree of heart rate increase is inversely proportional to the athlete’s ability to perform muscular work of a given power. It follows from this that heart rate during muscular work can be used as a reliable criterion for determining endurance.

It should be noted that when determining the performance of children of primary school age, a heart rate of 170 beats/min (during PWC) is sometimes unrealistic, so PWC can be used with this contingent (that is, work power is determined at a heart rate of 150 beats/min). PWC is measured in W or kg/min.

It is also impossible not to pay attention to the fact that the PWC test can be considered identical to the IPC test only at low and medium levels. At the maximum manifestations of endurance, the PWC test cannot completely replace the direct measurement of VO2 max.

We were talking about the heritability of aerobic endurance, but it turns out that the anaerobic mechanism for ensuring muscle activity is also significantly influenced by genetic factors. The heritability coefficient of this mechanism, according to most researchers, ranges from 70 to 80%. Moreover, many authors indicate that the heritability of anaerobic performance can be up to 90% or higher. The main indicator of anaerobic performance, as already mentioned, is the maximum oxygen debt (MAD).

It is well known that anaerobic performance largely determines not only the endurance manifested in relatively short but very intense work, but also underlies such a quality as speed. Consequently, based on the anaerobic energy supply for muscle activity associated with the manifestation of speed, this physical quality is often hereditary in nature. Individual differences in the manifestation of speed are also associated with the characteristics of the nervous system, which, as has been repeatedly said, are also mainly genetically determined.

Speed ​​is largely an inherited quality. In people inclined to sprint, the number of “fast” fibers, as noted, is 80-85%, “slow” - only 15-20%.

Hereditary predisposition is also found in the manifestation of reaction speed, the development indicator of which can be used with a high degree of reliability when selecting for sports that clearly require the manifestation of this quality (for example, goalkeeper in football, hockey, handball, etc.).

To a lesser extent than endurance and speed, strength is determined by heredity. But here it is important to note that relative muscle strength (strength per 1 kg of weight) is subject to genetic control and can be used as a criterion in selection for sports that require the manifestation of this quality.

Due to genetic conditioning, explosive muscle strength (manifested, in particular, when performing standing jumps) is also a fairly reliable criterion.

Absolute strength is determined primarily by environmental influences, is amenable to training and cannot be considered a criterion in determining athletic suitability.

Flexibility, the next conditioning physical quality, is also genetically determined and can be used as a reliable indicator in determining athletic suitability (primarily in technically complex sports).

It is believed that the influence of heredity on flexibility is more typical for girls than for boys.

With regard to coordination abilities (a factor that has a decisive influence on the development of sports technique), it should be said that they are also more often due to hereditary influence. This is explained by the fact that in most coordination manifestations, the properties of the nervous system, which are genetically predetermined, are of decisive importance.

Thus, we can conclude that the influence of hereditary factors on the manifestation of individual abilities for a particular sport is extremely great and finding “your own” is not easy. It is clear that from a genetic point of view, sports talent is a rather rare phenomenon. Most people show results in sports that are close to average, and there are very few people who are not able to do this, as well as people who are able to show results that are significantly above average. This distribution in the form of a curve is presented in Fig. 57 (Shvarts V.B., Khrushchev S., 1984).

Rice. 57. Normal distribution of individuals capable of showing athletic performance

If we consider elite sports, then such a distribution, determined by heredity, can give rise to pessimism among many who want to practice. But the fact that most people can achieve average (and near average) performance in sports should be an incentive to play sports in childhood and adolescence.

And even if, for example, after completing level II a teenager leaves the sport, the fact that he completed this level will leave a feeling of this achievement for the rest of his life. Subjectively, for a teenager, completing the category will be much more important than, for example, for someone who studied for several years at a music school (where there are no qualification standards) and stopped studying.

Another thing is that with children who are obsessed, but clearly do not have sports talent, it is necessary to carry out appropriate work, orienting them to knowledge of their capabilities, so that as a result of fruitless training they do not develop and strengthen a feeling of their own inferiority.

Many hereditary traits, including those that determine athletic fitness, are transmitted from more distant ancestors (not only from parents). This, first of all, can explain the fact that not all parents who are gifted in sports have gifted children.