Smart and stupid: what is intelligence and is it possible to inherit it
'28.01.2021'
Source: KNIFE
Until the herring learned algebra, we as a species define ourselves through reason, and it refers to intelligence. What does science know about measuring intelligence, why people are smart and stupid, and why do we need to know who is to blame: genes or environment - says KNIFE.
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There is not and cannot be a single gene that would encode intelligence and, in theory, could or may not be passed on to a child from parents. Yes, intelligence is a polygenic trait. Its components, cognitive skills, too. Poke your finger and shout: "Wo, intelligence!" - will not work. We see only particulars: so, is observed the relationship between speed of perception and IQ through common genetic traits. And the FNBP1L gene is associated with and childish, and with adults intelligence.
The heritability of intelligence has been studied on families, on twins, on siblings (brothers and sisters), in particular on adopted children, and now on huge amounts of data. So, the 2011 intelligence study was conducted on data from 3511 adults. 549 SNPs were studied - single nucleotide polymorphisms (that is, differences in DNA in the size of one nucleotide).
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According to the results of the study, 40% of variations of "crystallized" and 51% of variations of "mobile" intelligences are really related to geneticsthat is, intellectual differences are in part due to gene variations.
At the same time, the authors believe that the individual effects of specific snips are too small to be significant at the genome level, so a very, very large sample is needed to identify them. Scientists are getting closer to it. So, in a 2018 study being investigated already 248 people; 482 new genomic loci, 187 genes associated with intelligence ... Luxurious.
Throughout life, intelligence is plus or minus stable, if you make an allowance for insanity - thanks intelligence research, which the subjects passed twice, at 11 years and at 77.
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The level of heritability of intelligence is linear varies from year to year: from 20% of heritability in childhood to 60% in adult and 40% in adolescence. As we age, our genetic differences determine our intelligence more and more, and the influence of the environment fades away.
Previously, in science, the prevailing view was that the child was shaped by the environment, no matter what was given. Now scientists believe that as we get older, we begin to create for ourselves an environment that correlates with genetic inclinations, and intellectually change in accordance with it.
It used to be believed that if a professor is raised in a barn among piglets, a wild boar will definitely grow. Now it turns out that the professor, growing up, will arrange a university around, although I have never seen a graduate student.
What you inherited from your parents has become your own, personally chosen.
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High intelligence directly connected with education. Education, in turn, is with health and life: less educated people die earlier... A high intelligence and reliability promise longevity.
At the same time, all of humanity is getting smarter, this is called the Flynn effect. Namely James Flynn has openedthat from 1932 to 1978 the average American grew wiser by 13,8 IQ points, and then checked out how it is with other countries. It turned out to be growing too. Or grew up then: now experts suggestthat in the XXI century IQ will develop unevenly. In regions where this indicator is not high on average, it will grow by 6-7 points, but in the West it will add no more than one, and in the USA it will generally fall by 0,45 points.
Genes can affect intelligence in an unexpected way: he received a hereditary addiction to alcohol from his parents - if he didn’t realize it, he drank all his brains. But you don't need to blame everything on your mother. Heredity is not everything.
Plays a role in the formation of intelligence and food. For example, Richard Lynn, studying the Flynn effect, explained its availability of food: pregnant women and children eat better than before - that's the IQ and increases. The converse is also true.
On an intelligence test, underweight children on four of the five test parameters showed results worse than ordinary children. A child really needs to eat to develop. Grandma was right!
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But breastfeeding is not yet clear. IN one of the studies children with the G allele in the FADS2 gene did not show an increase in IQ from breast milk, and in infants with the C allele, it increased. But subsequent research on the role of FADS2 and breastfeeding in general in the development of intelligence do not confirm.
When examining the effect of breastfeeding on IQ, the researchers adjusted for the mother's education. The fact is that this in itself is a significant factor (hereinafter, it is proposed not to forget about the strong positive correlation between education and intelligence). A couple of years ago, newspapers even claimedthat the child's intelligence depends on the mother's intelligence. This applied mainly to boys. They say that the genes responsible for intelligence are located on the X chromosome, and children receive it from their mother. Since girls inherit X from mom and X from dad, and boys inherit X only from mom, boys are exactly as smart as their mothers. The news turned out to be fake.
But who the parents of the child are and how they live is really important for his intellect. Mothers education affects on the school success of children. This extends not only to the mother, but to the significant adult — the one who is mostly involved with the baby.
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Influences on the development of the child's cognitive skills the time that the mother spends with him in childhood. Reflected on intelligence, education and success parenting education - and is reflected throughout life. Research at the beginning of the century Betty Hart and Todd Risley of the "thirty million gap" states: children from poor families by the age of three they heard on average 30 fewer words than children from wealthy families. Our vocabulary is also the vocabulary of our parents ... but heredity has nothing to do with it.
We could believe in cognitive training, but for now can not seeso that they give an unambiguous result. Except for one thing: by 2020, the app and brain training industry will surpass 6 billion.
So if anyone wants to play solitaire, let him do it. And those who want to remember something, let it teach, and not rely on their experience of playing solitaire: special games train only the skill of playing, solving Sudoku - only the skill of solving Sudoku, etc.
