Translated material
Does humanity are stupid?
Civilization radically changed the human habitat and significantly weakened natural selection. How will this affect the properties of a person, in particular, on his intellect? Will it lead to sad consequences in the future? Or maybe already brought? This alarming issue is widely discussed in special and popular literature. A three-hobby joins the discussion: we publish an article by Alexander Markov , who has repeatedly spoke on this subject in his lectures. We hope to continue the discussion in the following issues of the TRV-hunger.
The study of the evolution of intelligence is an extremely complex research task with many pitfalls. Difficulties begin at the very beginning, when trying to determine the subject of research. Is there an “intellect in general”? Maybe we should talk about many different abilities not related to each other with completely different genetic and cultural bases? Someone, for example, copes with mathematical tasks, but is absolutely helpless in social interactions. Someone is well oriented on the ground, but cannot learn a poem.
Apparently, it is still possible to talk about “intellect in general”. The above examples of “one -sided” abilities are rather an exception. In large samples of the subjects, the results of different cognitive tests, as a rule, positively correlate with each other. That is, people who are good at the same types of tasks are well handled on average with others. This allows us to talk about general intelligence, which is also called the General Intelligence or General Cognitive Ability factor and which is believed to underlie the aforementioned positive correlation. Factor G can be assessed quantitatively according to the results shown by different figures in a variety of test sets. Usually he is able to explain a significant part (about 40%) of the total variability of these results. And most importantly - we can take one good test (for example, a standard IQ test), and we will have good reason to hope that its results with acceptable accuracy will reflect the desired “intellect”, or “general cognitive abilities” [1].
Like other phenotypic features, intelligence is partly determined by genes, partly the environment (in the broadest sense). If we are talking about people, then the “environment” is primarily a culture, again in the broadest sense (everything that is somehow determined by the accumulated experience and knowledge of previous generations). Without culture, we are not people, without obtaining a huge amount of information from other people (including through intermediate media like books or web pages), we will have any intelligence [2]. However, without a normally working brain of intelligence, of course, there will be no. And for the normal development and work of the brain, we need genes polished by millions of years of natural selection. The brain, by the way, is the most “genome” of our organs: at least a third of the genes of our genome (and about 20,000 of them there) are predominantly expressed (that is, they work) in the brain.
It is logical to assume that the allel variants of many of these genes affect cognitive abilities. This is really so, according to modern genetic research. It is shown that intelligence has high inheritance . This means that a significant part of intelligence variation (somewhere about 10–20% in young children and 40-60% in adults) is explained by genetic differences between people. Why genes affect adult intelligence more strongly than children - a separate interesting topic (perhaps because young children have less opportunities to choose the cultural environment, environment and lifestyle that are appropriate for themselves, and with age, for example, people begin to read more smart books or choose more smart comrades, becoming even smarter). Now it is important for us that modern people have greatly affect intelligence, which means that this sign can evolve. Here it is necessary to make a reservation that all the behavioral and psychological features of a person, including intelligence, can evolve in two ways: genetically and culturally. At the same time, cultural evolution greatly affects the orientation of the genetic, and that, in turn, with some delay can have a reverse effect on the cultural one. We are now talking about genetic evolution, but we must not forget that in the case of a person, it is not only difficult, but almost impossible to completely separate it from cultural.
Flynn effect
The effect consists in the growth of the average IQ in several Western countries (where measurements were carried out) for decades, from about the 1930s to 2000s. In the area of the 2000s, growth ceased, and in some places went into the decline (Flinn's opposite effect). The effect, most likely, is not related to genetics - it is too fast. It is assumed that it has a cultural origin, first of all, this is the result of a coaching for tests, both on IQ itself and for examination, such as the exam. For explanation, improvement of living conditions is also attracted (good nutrition has a beneficial effect on the brain). The reasons for the opposite effect of Flynn can be very different: the effect of shoaling has been exhausted, the education was sided, the cultural background was degraded, etc. Again its temporary scale is too short for genetic changes.
At the same time, scientists have reason to believe that the genetic evolution of intelligence in modern people (at least in the most studied societies designated by the abbreviation Weird: Western, educated, industrial, rich, democratic) is directed in the wrong direction in which we would like. This orientation, of course, is set by culture. People may be gradually stupid at the genetic level. It may be difficult to believe in this, because phenotypically we are more likely to smart. This is indicated, in particular, the so -called Flynn effect (which, however, in some countries is already naught and even turns back), as well as the ongoing growth of the level of education. But here the genetic basis of intelligence, apparently, is slowly spoiling. The following facts and considerations testify to this.
1. According to paleoanthropologists, the average brain volume of people stopped growing and even began to decrease about 20-30 thousand years ago. Over the past two millions of years, the brain volume of our ancestors increased three times. This is an unheard of brain growth rate by evolutionary standards. Considering that a large brain is an extremely expensive pleasure (consumes a lot of calories, complicates childbirth, forces to give birth to children underdeveloped and helpless, which sharply increases the burden on parents and the total “price” of reproduction), its rapid growth indicates a strong selection in favor of brainwashed individuals or groups in which there were such individuals. In other words, our ancestors with the brain left more significantly more descendants than their competitors with a smaller brain. Why did our ancestors need a large brain, what advantages he gave? Most likely, these advantages were primarily associated with the improvement of cognitive abilities. What kind of cognitive abilities suddenly turned out to be so in demand and why exactly our ancestors are a separate interesting issue that goes beyond the scope of this note (my considerations are presented in the article [3]).
If, after two million years of persistent growth, the brain suddenly began to decrease, this suggests that we may have stopped dying and even began to stupid a little. The weak point of this reasoning is that the brain in principle can decrease without losing cognitive functions-for example, due to some cunning reorganization and optimization. Modern people have a positive correlation between the volume of the brain and the mind, but it is quite weak. There are many wise men with a small brain, and vice versa.
2. Weakening of selection against mutations that disrupt cognitive functions. Mutations arise constantly: according to the latest (very reliable) estimates, each newborn in the genome of about 70 new mutations, which dad and mother had no on average. If we assume that these mutations are distributed according to the genome by accident, it can be expected that approximately 2-5 of them affect the area of the genome, the normal functioning of which is important for the development and functioning of the brain. The calculation is: functionally important sequences make up about 10-15% of the genome, the rest is in the first approximation of garbage; About a third of functional sequences are important for the brain. As already mentioned, the brain is a very “genome” organ, which means that it is extremely sensitive to mutation damage. Mutations that spoil something arise much more often than those that improve. Simply because there are many more ways to ruin a debugged complex system than to improve it; This is sometimes called the "principle of Anna Karenina", because, indeed, "all happy families are similar to each other, every unlucky family is unhappy in its own way."
Typically, harmful mutations are rejected by selection: their carriers leave less viable descendants. But in people in the last 100-200 years, selection against mutations that violate the work of certain body systems (immune, nervous, etc.), apparently, has sharply weakened. Thanks to the development of medicine and other cultural achievements, early mortality has decreased greatly in most societies, and in Weird countries it has completely approached zero. In addition, societies began to carefully care about people with disabilities, and indeed about everyone in a row. All this at least aligns the chances of survival and reproduction for people with “good” and “bad” genotypes, including people who differ in alleles affecting cognitive functions. Well, if the selection against such alleles weakened, then their frequency in the gene pool will inevitably grow. After all, we remember that the new “bad” mutations arise constantly, and if they do not roll them, they will accumulate. As a result, humanity will gradually "genetically stupor." For the time being, cultural evolution, more fast and powerful than genetic, can compensate for this - for example, by improving the quality and accessibility of education. And then? According to the largest specialist in this area, A. S. Kondrashov, the problem of the genetic degradation of mankind due to the accumulation of genetic cargo (and it, by the way, is not only about mental and sincere, but also about physical health) can begin to vaguely manifest after a dozen or two generations. And then, perhaps, it will be too late to do something [5]. Here you can fantasize about the collapse of civilization and a return to savagery and barbarism. However, after that, a positive intelligence selection must probably earn again.
These reasoning have a lot of weaknesses. For example, the aforementioned 70 mutations are most likely a pretty cleaned sample, from which the worst mutations have already been deleted. After all, no one has canceled prenatal mortality, and embryos with “bad” genes continue to die in many. If society begins to carefully care about them as already born, the mutation degradation of mankind can be greatly accelerated. But for now, we can hope that of the 70 new mutations available to each newborn, very few (certainly not five or even two) are really harmful to the brain. Some other objections can be brought (a special section is devoted to them in the final part of my two -volume “Human Evolution” [6]). Most likely, from the accumulation of the genetic cargo, we will not die out as a species, but many usual benefits can lose.
3. The selection against the "genes of intelligence." In addition to the passive accumulation of “bad” alleles due to the weakness of the cleansing selection, the intellectual status of mankind may be threatened by a more serious evolutionary force: the real selection in favor of these alleles, the selection for deepening. Genetic studies, including based on powerful modern methods as a full-genomic search for associations (Gwas, Genome-Wide Association Studies), showed that the intellect is affected by many genes. At the same time, the influence of each gene separately is very little, but all together they make a significant contribution to the observed variability in cognitive abilities. All this, of course, is also mediated by culture, and what is true for Weird, is not necessarily true for “traditional” peoples from conditional jungle. But in Weird countries, the inheritance of the intelligence is high, and many dozens of specific genes have already been found, the variations in which affect the sign of interest to us. Scientists actually do not recommend calling these genes “intelligence genes”. There are many reasons for that, among which the extreme weakness of the effects of individual genes, and the presence of their heaps of other effects in addition to impact on intelligence, and the strong dependence of the genetic effects on the cultural environment, and most importantly, the danger of being not so understood by the wide public and get the stigma of justifying (supposedly) social inequality. But we will still call them “genes of intelligence” for brevity and with all reservations. So, studies have shown that in the countries of Weird (according to other data countries there are much less), many “intelligence genes” part -time are also “genes of education” and even “genes of wealth”. Among them, as one might expect, the share of genes involved in the development and work of the brain is increased.
Thus, these three signs (intelligence, education and income) not only correlate with each other (which is well known for Weird countries), but are also determined in many respects of the same genes. In addition, many alleles, positively affecting these signs, also correlate with good health and high life expectancy. The logic here is that a person, exhausted by diseases, is less likely to fully develop his intelligence, get a good education and achieve financial prosperity, even if his illness is not brain (see the drawing below).
The saddest thing is that they, apparently, not only got out of the action of negative selection, but also fell under the selection of positive. It seems that the “good” alleles, which increase the likelihood that a person will grow smart, will receive a good education and will be economically successful, are slowly pushed out of the gene pool and are replaced by competing “bad” alleles.
The fact that in developed countries, starting from the middle of the 19th century, more smart, educated and successful (economically and socially) people leave on average less descendants than their less successful fellow citizens have long been known. That is, there is a negative selection for these phenotypic features (the fact that the numerous offspring of low -consuming people receives less high -quality parental care has ceased to have evolutionary significance about the same time, and also in connection with a radical decrease in mortality, humanism and other cultural achievements). Large scientists, among whom were one of the creators of the synthetic theory of evolution (and at the same time mathematical statistics) Ronald Fisher, has long expressed appropriate fears. But only recently genetic studies based on the analysis of genomes of dozens and hundreds of thousands of people with a well -known phenotype and life history have convincingly showed that the selection works directly against the genes of intelligence, education and wealth. As it turned out, in order to have reduced chances of successful reproduction (i.e., the expected number of children below average), you do not even have to be smart, educated or rich, but just have a genetic predisposition for this . For example, a large -scale study conducted in Iceland showed that people with a large number of alleles that increase the likelihood of obtaining a good education leave an average of less children, even if they do not receive a good education [7].
How can this work? For example, like this: people with good cognitive abilities are often thinking about the future and plan a career. Therefore, on the one hand, they are more likely to go to a decent college, and on the other, they will postpone the birth of children “for later”, in order to find a good job first, buy a house, etc. And I must say that at the moment when the thought arises in the human head that there is no need to have children at 18 years old, and it is better to achieve something in life at this very moment (reproductive success) with this person with this person) A loud bang collapses. Especially if everything happens in the era of universal accessibility of family planning means (this, by the way, is an example of how cultural evolution affects the genetic one). The prolific period of our lives is short -lived, and the expected number of children is associated with the age of birth of the first child with a very strict reverse dependence.
Icelandic scientists also showed that the frequency of the “education genes” in the Icelandic gene pool is really reduced, and that if everything goes on, the average IQ population will fall by about three points per century (of course, without taking into account such cultural phenomena as the Flynn effect, the opposite effect of Flynn, etc.) Similar results were obtained on the samples of the US inhabitants [8] and The United Kingdom [9].
It is also important that the development of civilization, humanism, support for the disadvantaged and the struggle for the equality of opportunities can make natural selection (if it is in principle) more effective. After all, this is essentially aligning the “environmental conditions” for all segments of the population. As a result, the share of the “environmental” variability of phenotypic features should be reduced and the share of genetic variability is growing. The term “inheritance” mentioned above can be defined in the first approximation as the ratio of genetic variability to the general variability of the sign. If you create equally favorable development conditions for all people (what many societies strive for), then the environmental variability by phenotypic characteristics, including intelligence, will decrease, and genetic variability will come to the fore. The inheritance of the signs, respectively, will grow, and therefore the selection - with its unchanged intensity - will give more tangible results (according to the well -known “Breeder's Equation) R = SH 2, where R is the effectiveness of selection, S is its intensity, and h 2 is inheritance). In general, if the negative selection of intelligence genes is real, then humanism and concern for universal equality can enhance its effect.
Idiocracy (2006)
The satirical film Mike Jaja, the creator of the animated series about Bivis and Batthead. The preamble shows the fate of the two families with IQ 140 and 80. The first postpones the birth of a child many times and ends with the fact that the husband dies during masturbation for IVF, the second is distorted by a powerful genealogical tree. The hero of the film is a librarian with average abilities, who, due to an unsuccessful experiment, falls into the distant future (2500), where he is the smartest person in the world.
How serious is it and is it time to panic already? There is no exact answer, but, most likely, before the implementation of the film “Idiocracy”, we still have some generations in the reserve of some generations. To prevent this from happening, it is necessary (at least) to seriously study everything that was said here, and not hide their heads in the sand and the more not to stigge scientists who dare to take on such explosive topics.
In the end, I note that the “global deepening” and even the collapse of civilization, in principle, can occur at the expense of cultural evolution alone, without the help of genetic evolution. Cultural evolution has long (maybe from about the time when the brain has stopped growing in our ancestors) affects our lives much faster and more radically than genetic. But this is another story.
Alexander Markov,
doct. Biol. sciences
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