Are we getting smarter or getting stupid?
So what's going on with our intelligence?
Dmitry Tselikov, CompulentaAnd again the old question: is humanity getting smarter or getting stupid?
It seems to be both at once. A new study has shown that, although IQ is growing at an amazing rate, the genetic potential behind it can decline, and a representative of the Victorian era would beat our contemporary in an intellectual battle.
This conclusion cannot be called indisputable, because it is not known for certain whether the measurement methods used really expose the level of intelligence. And then, the mind is a complex concept: what makes an inhabitant of the African savannah smart is not useful in the financial centers of Hong Kong.
"It is impossible to say unequivocally whether we are getting smarter or stupid," says lead author Michael Woodley from Umea University (Sweden). "The components of intelligence change in different ways."
Lightspring Illustration
It may seem obvious that the world has become smarter: smartphones, heart transplant operations, understanding the connection between microorganisms and diseases...
In addition, there is the Flynn effect, named after intelligence researcher James Flynn, professor Emeritus at the University of Otago (New Zealand). Since IQ tests (IQ coefficient) have been revised and calibrated several times over the past hundred years, scientists suggest that volunteers take tests of previous generations to identify the Flynn effect. Mr. Flynn and his colleagues found that all over the world, new generations score higher in old tests than those for whom they were created.
Moreover, the growth is rather big: on average, over a decade, the IQ of mankind jumps by about three points (with geographical variations, of course).
Mr. Flynn and many other researchers suspect that rising IQ scores reflect improving living conditions. IQ is influenced not only by heredity, but also by the environment: give young people the opportunity to get an education, and their IQ will increase. A healthy diet, more study, more incentives to be smart–that's the explanation for the Flynn effect.
Thanks to education, modern people think differently. Ask someone from the XIX century about how a dog and a hare are related, and they will answer you, based on simple life experience: "A dog hunts a hare." Now people are accustomed to thinking more abstractly, and most are likely to point out that both the dog and the hare are mammals. "Apparently, the habit of this kind of heuristics has led to the fact that modern people approach IQ tests differently," Mr. Woodley believes.
Nevertheless, there are researchers who believe that all this is a hoax, and humanity is becoming more stupid.
In November 2012, Gerald Crabtree from Stanford University Medical School (USA) published two articles in the journal Trends in Genetics, where he tried to prove that human intelligence reached its peak 2-6 thousand years ago.
Mr. Crabtree was based on the data of genetics. According to him, a person's mental abilities depend on 2-5 thousand genes. By the rate at which genetic mutations accumulate, he calculated that within the last 3 thousand years, all of humanity has acquired at least two mutations detrimental to the "intelligence genes" (and will receive a couple more in the next three thousand years). Not every mutation is harmful, because genes "walk" in pairs, and weaknesses acquired as a result of mutation of one gene can be compensated by the healthy part of the pair, Mr. Crabtree wrote, but his calculations showed that our mind is not as persistent as it may seem.
In addition, according to the scientist, today intelligence no longer plays the important evolutionary role as in the days of hunters and gatherers. Thousands of years ago, not being able to understand the aerodynamics of a spear meant that you would end up at a lion's dinner and would not be able to pass on your set of genes to descendants. And today's people very rarely risk their lives by taking an intelligence test.
Another theory says that the genetic base of intelligence is in decline due to the dysgenic reproduction of humans. Studies have shown that since the middle of the XIX century, IQ and reproduction correlate negatively: the smarter a person is, the fewer children he has. Since the mind partly depends on genetics, some experts believe that the IQ of humanity should decrease.
But in reality, the indicators are growing, and Mr. Woodley and his colleagues tried to explain this paradox of the theory of dysgenic reproduction.
To study intelligence from a historical perspective, the researchers turned not to IQ tests, but to reaction speed, which, according to Mr. Woodley, correlates with IQ and is not as sensitive to cultural factors as IQ tests. There is a simple thing in mind: the amount of time required to respond to a stimulus reflects the effectiveness of the most elementary cognitive mechanism.
In the 1880s, the English scientist Sir Francis Galton measured the reaction rate of 2,522 young men and 888 girls with very different socio-economic status. The average of the first was 183 ms, the second - 187 ms. (Galton conducted this experiment as a pioneer of eugenics, that is, the theory that only the "best" should reproduce. At the beginning of the XX century, Galton's ideas were liked by many high–ranking officials, especially Adolf Hitler, who dreamed of a "race of masters" - the Aryans.)
After 1941, twelve similar studies were conducted, and they gave completely different results: 250 and 277 ms, respectively. A review of these experiments was published in 2010 in the American Journal of Psychology.
Mr. Woodley and his colleagues expanded that work by getting additional information and comparing old and new studies in order to be sure that the same things were measured.
Despite the fact that chronometers have become much better since the 1880s, Mr. Woodley is confident in the accuracy of Galton's measurements. He used pendulum mechanisms, the error of which, according to Mr. Woodley, does not exceed 10 ms.
Galton's data are also distributed as needed: for example, groups with a relatively high inbreeding rate showed poor results.
The result was confirmation of the conclusions made in 2010: the reaction rate decreases, that is, the most stable, genetically determined elements of intelligence deteriorate.
This suggests that although IQ scores are increasing with the ubiquity of education and the improvement of the quality of medical care, a person's ability to be smart is decreasing. According to Mr. Woodley, the Flynn effect hides like dark matter on the other side of IQ tests. To use an agricultural analogy, seeds are getting worse, but the quality of fertilizers is increasing.
Why are we genetically stupid? There are a lot of possible causes – from neurotoxins to natural selection.
But not all scientists are ready to accept this point of view. "If you summarize a hundred years of research, you can see a reliable correlation between the measurement of reaction speed and the measurement of IQ, but the sequence of such correlations is too short for them to allow the former to explain the latter," says psychologist Theodore Nettlbeck from the University of Adelaide (Australia).
In other words, judging IQ by reaction speed is wishful thinking. At best, the rate of reaction to complex stimuli can explain about 20-25% of IQ variability, and a simple reaction is even less.
Mr. Nettlbeck also fears that the results of dissimilar experiments were compared incorrectly. "The difference was not only in time measurement technologies, which really could not affect the result, but also in numerous procedural nuances: the number of participants (hence the different degree of confidence in the averages), the specifics of their instruction, the nature of stimuli, the forms of reactions – all this could affect the response rate," the specialist emphasizes.
The reaction rate is also difficult to interpret, James Flynn notes. "A fool and a smart person have the same peak reaction rate," he says. The difference between them is that a person with a low IQ loses concentration faster, and therefore his performance during the experiment will vary more than that of a participant with a higher IQ.
And here the question arises about what is actually measured: intelligence or the ability to remain attentive for a while?
There are other factors, Mr. Flynn adds. For example, Hong Kong schoolchildren are much faster in reaction tests than their British peers. We can say that Hong Kongers are smarter, but we can interpret the results in a different way: the Chinese are more likely to take risks.
But even if Mr. Woodley and his colleagues are right, this does not mean that our species is doomed to degeneration. According to Mr. Flynn, Norway and Sweden are exceptions to the rule that less educated people with relatively low IQs have more children. And the widespread increase in the coefficient suggests that cultural factors are still coping with the impoverishment of the genetic base of intelligence.
"Apparently, not everything is clear with genes," Mr. Flynn emphasizes.
Based on LiveScience: Are Humans Getting Smarter or Dumber?Portal "Eternal youth" http://vechnayamolodost.ru