Genetics & Intelligence
Is intelligence a merit of nature and heredity, or is it acquired skills and abilities? Scientists have been arguing on this topic for decades, trying to unravel the mystery of high IQ, genius, and various talents. The complexity of this issue is also in the fact that it is not so easy to evaluate intelligence. And it seems unrealistic to find out what abilities we inherited from our parents, and which ones are solely the achievements of our perseverance.
Yet, science does not stand still, and with the development of genetics, scientists have not only come to unravel the nature of genius, but have also managed to identify the genes responsible for our intelligence. But first things first.
What is intelligence and how can it be evaluated?
First, let’s understand what intelligence is. This concept can be interpreted in different ways, but the essence is always the same — it is the ability of the brain to perceive, analyze and remember information. Some researchers believe that intelligence always exists in the context of a specific task, while others argue that it is a biological feature of a person, which refers to the physiological, neurological, biochemical and hormonal basis of cognitive behavior.
Scientists have been studying and evaluating intelligence since the 19th century. And the first IQ tests appeared as early as in the early 1900s. Many of them are still in use today, as they all focus on the same thing — an assessment of general cognitive abilities (G factor). The purpose of the IQ test is to evaluate a person’s ability to remember information, attention, language skills, vocabulary, abstract and spatial thinking. The higher IQ, a person has, the better he is at performing tasks from different areas, whether it is a math sum, memorizing a poem, or the public speaking skills.
However, IQ tests are often criticized by neuropsychologists and geneticists, who claim that the key to intelligence lies elsewhere. Tests do not always show a reliable image of reality. For example, the same person may score high on intelligence tests, but fail to cope with common household tasks.
Where does intelligence come from?
After all, is intelligence inherited? Partially- yes. This was announced by an international team of scientists in 2017. They had identified 52 genes linked to intelligence in nearly 80,000 people. The genome of the volunteers was analyzed to look for similarities and differences in certain gene regions. In total, scientists have counted more than 50 genes that directly affect our intellectual abilities.
One of the genes is involved in the regulation of neuronal growth; the other is associated with mental disability and cerebral vascular malformation. One way or another, these genes affect human intelligence.
Another study conducted in 2018 in Scotland showed that at least 538 genes are responsible for our mental abilities. All of them are inherited, which means that we definitely inherited some of the intelligence from our ancestors.
Also, studies on identical twins had a great influence on the study of intelligence and heredity. It is known that identical twins are born from one egg that has split into two or more. Consequently, these children have the same DNA. Scientists have always wondered what differences in intelligence will be in genetically identical people. For example, in the 1990s and 2000s, Russian geneticists were studying the extent to which intellectual ability is related to heredity. Using an encephalogram, they examined 100 pairs of twins at rest and during various activities, and after 5−6 years they repeated the analysis with the same people. It turned out that heredity plays an important role in the issue of intelligence. So, the level of intelligence in identical twins was almost the same, even if people were brought up in different families and conditions.
Does everything depend on genes?
It should be noted that intelligence is influenced not only by heredity, but also by the wealth of the family, the quality of education, upbringing, the environment and one’s own motivation, and many other factors. You will not become an educated person, just having "good genetics". Erudition, a broad outlook, competent speech are also important. Our genes are just the foundation, because intelligence is a very multifaceted concept. Speaking about people with a high level of intelligence, it is easy to see that almost all of them have an inquisitive mind. It is not enough just to have a certain set of genes. What matters is how a person deals with his abilities.
The environment has a great influence not only on our behavior, but also on our mental abilities. The chances that a child will reach for knowledge are high in the social environment of scientists or just well-read and educated people. As well as vice versa: the owner of the "genes of genius" will not prove himself in any way being surrounded by illiterate lazy people.
A person is a unique product of his environment and genetics, where everything is closely interconnected. Nevertheless, research in neuropsychology and molecular genetics is important. It provides a scientific basis for a better understanding of how the brainwork can be controlled to enhance intelligence.
Perhaps, scientists will never be able to uncover the "genius gene", but in the process of genetic research, which is growing deeper and deeper every year, new sections of genes are being found. Many of them may be useful for the relief and treatment of dangerous genetic diseases.