Intelligence in one snip?
US Air Force patents DNA intelligence test
Ahead of the future, they bring back the dark past
Marat Kuzaev, TASS
Genetics is developing before our eyes and generates biological fatalism – a mystical belief in fate written in our cells. There are also those who do not want to put up with a foregone conclusion and are ready to go far
On March 21, a patent application filed by the US Air Force was published. It describes a method for predicting a person's mental abilities using a genetic test. This method is simple by modern standards: a person takes saliva, blood or another sample for analysis and searches for a single one of the 3 billion pairs of nitrogenous bases in his DNA – a gene book with instructions for assembling the body. If DNA really were a book, it would be like opening page 138, counting 13 lines from the top and seeing which letter is the sixth from the left.
The right place in the human genetic code has a special designation – rs914246. There is one of two "letters": either adenine or cytosine. The level of substances affecting the work of brain cells depends on which nitrogenous base a person got from his parents. And the interaction of cells affects intelligence, especially working memory – the ability to hold information in the mind. Two copies of each gene are inherited from the father and mother, so the combination of "cytosine – cytosine" is better than "cytosine – adenine" or even more so "adenine – adenine". At least, that's the theory outlined in the patent application.
But predicting the power of intelligence by one change in a particular gene is like guessing the denouement of a detective story by a single letter in the middle of a chapter.
Genetics of intelligence before Genetics
The science of genetics appeared largely due to luck. The Austrian monk-naturalist Gregor Mendel, who formulated the laws of heredity in the XIX century, derived them from observations of pea hybrids. He looked at the color of the pods, the shape of the peas, the height of the bushes. Coincidentally, these and several other signs of the plant are determined by single sections of DNA. Later, such signs were called Mendelian.
A single gene can sometimes affect a person. For example, just one defect in DNA is enough to develop sickle cell anemia – a serious disease in which red blood cells change shape and carry oxygen much worse. Huntington's chorea occurs in a similar way, which the Thirteenth doctor from the TV series "Doctor House" was ill with: because of a mutant gene, brain cells begin to die - a person's coordination of movements is disrupted, dementia develops and eventually death occurs. By analogy with the signs of such diseases – Mendelian. Hardly anyone else has been named after so many horrors.
Mendel was lucky with peas, but otherwise not: during his lifetime, his theory went unnoticed. There were several reasons for this, one of them was that the scientist's conclusions contradicted intuition. Although Mendel did not use the word "gene", he meant that each individual receives two copies from the parents, and only one is manifested. But if you look at children, they usually look like both mom and dad: in appearance, the offspring is the "arithmetic mean" of the parents, and not one of the two. The fact is that, as a mosaic consists of individual pieces, most of the traits of an organism are determined by many, sometimes hundreds or even thousands of genes.
Among these traits is intelligence.
In a broad sense, intelligence is the ability to learn, reason, and solve problems. Unlike his height or eye color, you can't just see him, so special tests have been developed with tasks for calculations, spatial orientation, logic, etc. In addition, people are able to assess the mind by eye (and do it constantly, often to the displeasure of others). The townsfolk even deduced their own laws of heredity: for example, nature rests on the children of geniuses.
Whether intelligence is transmitted from generation to generation, they tried to find out long before Mendel. More precisely, at first the subject of research was not the mind, but madness. At the end of the XVIII century, about 100 years before the experiments of the Austrian monk, madhouses began to open everywhere in Europe and America, where they collected statistics about patients, trying to find the causes of their illnesses (as well as for planning work and reports to officials). In England, the issue has acquired state significance: King George III's mind has become muddled, instead of which the regent has ruled for the last ten years.
By the time genetics took shape into a science, a lot of data on the inheritance of mental disorders and intelligence had accumulated, but these questions still occupy researchers. Opinions differ. In the book "DNA is not a sentence", recently published in Russian, psychologist Steven Heine wrote that the contribution of genes to mental abilities is estimated at 10-80%. Such different estimates of "merit" are only for children who broke a window and got caught red-handed.
How the intelligence genes were searched for
Before scientists managed to decipher human DNA in 2003, the inheritance of intelligence was judged mainly by twins, adopted and ordinary children. If brothers or sisters appeared from the same egg, then their genes completely coincide. So, the differences between them are due to something else - the environment in which they grew up and live. And when twins are fraternal, their DNA differs just like any other siblings. But they grow up in conditions similar to those of identical twins. Anyway, they have a brother or sister of the same age. It is convenient to compare different groups to clarify the strength of heredity.
When the decoding of the genome became cheaper, candidate genes were tested based on hypotheses about how they could affect intelligence (or any other trait). The gene from the US Air Force patent application is just such a candidate. Scientists know that it affects the level of substances in the brain, because of which, in theory, a person thinks better. But this is just a guess. To test it, you need to find people with high intelligence, see what version of the gene they have, and better yet, compare them with a control group of average intelligence. As Heine writes, most of these attempts have failed.
Decoding the human genome cost $2.7 billion at the 1991 exchange rate and took 13 years. Now consumer DNA analysis, when thousands of genes are checked, costs less than $ 1 thousand and is being prepared for only a few months. Companies that provide such a service have collected huge databases. By agreeing with them, researchers get the most valuable information – they just need to extract it.
To do this, a genome-wide association studies (or simply GWAS) is carried out. Stephen Heine compared the testing of candidate genes to a targeted military strike, and GWAS to carpet bombing. Researchers take huge samples of people and look at differences like the one mentioned in the US Air Force patent application. There are no preliminary hypotheses – the researchers check not one, but in general all the sites recognized during the analysis. Then they compare the DNA of people with a certain trait, for example, patients with depression or those with extraordinary mental abilities, and the genome of those who do not have this trait. After complex statistical processing, the identified features in the genes are considered to be related (associated) with a particular trait. However, the results need to be checked in other studies: often the associations are imaginary – they manifest themselves by mistake.
"The most optimistic results in terms of the connection of mental abilities with genes were obtained in a series of experiments with huge samples. Scientists found three genetic variants, each of which on average determined only 0.3 IQ points," Heine wrote, meaning that the efforts of scientists yielded almost nothing. But his book has just been published in Russia, and it appeared in the original in April 2017. A lot has changed since then.
Breakthrough of 2017
In 2017, articles were published about two GWAS with previously unseen samples. In the first, scientists tested the DNA of 78 thousand people and found 18 sites with differences in one "letter" related to intelligence. The sample of the second one was already 280 thousand people, and the number of sites found increased from 18 to 206. In 2018, the results of an even larger study were published, where the DNA of about 1.1 million people was studied. If a year before, geneticists could explain less than 1% of the differences in mental acuity, now it is 7-10%.
Commenting on these works in the article "New Genetics of Intelligence", psychologists Robert Plomin and Sophie von Stumm said that 10% is not the limit – the GWAS method can explain up to a quarter of the differences in intelligence, and in general, judging by identical twins, intelligence depends on heredity by 50%. Simply put, whatever you do, the mind is half determined by natural inclinations. "Nothing in our brain, as well as behavior and the environment, is capable of changing inherited differences in DNA," Plomin and von Stumm wrote.
But there are reasons to believe that this is not the case. DNA is usually compared with the instructions, but this instruction still needs to be executed. Recent studies have shown that the implementation of the program recorded in the genome largely depends on parental care in childhood and other external conditions. And in the work of 2018, it was shown that if a mother does not pay enough attention to children, they have mutations in brain cells. It is not really known how this affects the further development of offspring and whether the same thing happens in humans (the experiment was conducted on mice), but DNA is not set once and for all.
Heredity and environment are usually contrasted – in English, the sonorous phrase nature vs nurture (lit. "nature against nurturing"). The experiment on mice has thrown a bridge between the shores, but this is only one separate case, and there are plenty of questions left. For example, Heine's book says that the heritability of intelligence in rich people is much higher than in poor people. Precisely because of this, the assessment of the influence of genes ranges from 10-80%. And Plomin and von Stumm in their article said that in other studies this pattern was not confirmed. And these are not the foggiest places yet.
Most of the DNA was considered junk just a few years ago, and the purpose of huge sections of this molecule is still a mystery. There are "stars" among the genes that are studied in laboratories around the world, but about a quarter of them have no research at all. The genome has been decoded, but it is unclear exactly how many genes it contains. However, there is not even a generally accepted definition of a gene.
Mental abilities, of course, are inherited – we just barely understand how it happens. Perhaps most genes are intelligence genes, so in a sense there are no intelligence genes, just as there are no special DNA sections responsible for depression, diligence or religiosity. Genes don't make a person sad – they make proteins and something else that remains to be guessed.
Advanced research methods give only a rough idea of how intelligence is inherited. Nevertheless, biotech companies, and scientists themselves, offer to use the results obtained and give advice to politicians, officials, businesses and ordinary people. These recommendations are sometimes reminiscent of the most terrible episodes of history.
Intelligence as a political concept
Intellect, more precisely, reason, is the main theme of European philosophy, if not of the entire culture since Plato. Plato believed that the world can be comprehended by the mind and that intelligent philosophers should rule the rest of people. His disciple Aristotle believed that intelligence is an innate trait that not everyone possesses. Those who do not have it are obliged to obey. For subsequent thinkers, the mind was also a dividing line separating man from other creations of God – or from each other.
The idea that people's mental abilities are different served as a justification for colonialism, racial segregation, and later eugenics. When Charles Darwin outlined his theory of evolution, his cousin Francis Galton thought that natural selection could be manually directed to improve the human breed. In the XX century, eugenic ideas formed the basis of laws. The first thing that comes to mind is the horrors of Hitler's Germany, but in fact, the Nazis almost did not invent anything themselves, and most importantly, little has changed since the Second World War.
In the Canadian province of Alberta, the law on the forced sterilization of patients in psychiatric hospitals and some other state institutions was repealed only in 1972. Similar laws were in effect in most American states and Scandinavian countries. In the essay "Eugenics has not disappeared anywhere," philosopher Robert Wilson recalled that in Australia, mentally retarded girls and women were sterilized against their will back in 2012.
"To say whether someone is intelligent or not has never been just a comment about mental abilities. It's always a judgment about what that person is allowed to do. Thus, intelligence is a political concept," wrote former diplomat and philosopher Stephen Cave in an article about the history of intelligence since Plato. It begins with a story about how, at the age of 11, Cave, along with thousands of other British schoolchildren, passed a centralized intelligence test. According to the results of this check, the children were assigned to different schools, and their future fate depended on it. In some regions, testing is still being carried out.
Of course, an IQ test cannot be compared with forced sterilization, but still this practice shows what importance is attached to the mind and with what zeal they try to measure it in order to draw conclusions about a person. Genetics provides new tools for this. "Polygenic scores will be used to determine genetic aptitudes for learning, reasoning and problem solving [...] as a consumer service. We predict that companies will routinely provide results along with scores on hundreds of other medical and psychological indicators calculated after genome–wide analysis," Plomin and von Stuff suggested in the New Genetics of Intelligence.
Genetics for everyone
But if intelligence plays such an important role in life, then people are unlikely to be satisfied with tests. Pharmacies sell nootropics without proven effectiveness or simply useless, video games are sold in app stores ostensibly for brain training, and in bookstores there are entire shelves with literature for the development of mental and creative abilities. To become the best version of yourself, any means are good.
"If a young person wants to improve his working memory, then he may have one or more opportunities for this. [...] For example, a diet taking into account genetic characteristics and dietary supplements that increase vitamin B9 levels for individuals without cytosine in the rs914246 DNA region or with cytosine but low gene activity. Another option is brain training for people without cytosine. [...] Other options may selectively include recommended DNA modification to improve working memory," the US Air Force patent application says.
You should not follow these tips. According to Steven Heine, the theoretical justification for this invention looks unconvincing. "I would be very surprised if it is confirmed that this variation of the gene accurately predicts how good a person's working memory is," said the psychologist (Kevin Schmidt, listed in the application as the inventor, did not respond to the letter from TASS). But another thing is important – the state department, as if nothing had happened, talks about the genetic improvement of people.
Gene editing technologies are not yet safe and accurate enough to apply them to humans. But this did not stop the Chinese scientist He Jiankui, and last year the first "GM children" were born. He made only one mutation, and in order to significantly affect intelligence, hundreds, if not thousands of DNA edits will be needed. The record until recently was 62 man-made changes in one cell. But at the end of March, an international team of scientists announced that they had successfully edited the cell 13.2 thousand times. This does not mean that tomorrow there will be hordes of designer people, but nevertheless genetics is rushing forward with stunning speed.
This cannot be said for sure, but perhaps in the foreseeable future we will better understand the work of genes, we will really be able to discern intellectual inclinations even before a person was born, we will know how to reveal and even improve them. Then unprecedented social inequality may arise. But whether it is right to predict and increase intelligence is a false question. If such an opportunity arises, there will be those who want to do it for themselves or for their children, and those who will satisfy the demand. Therefore, the real problem is how to provide genetic technologies to everyone.
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