Since the 70s, the IQ of people has not only stopped growing, but has decreased considerably. Discover the causes for which we are increasingly dumb.
Paradoxically, in 1984 the American psychologist James Flynn calculated that between 1932 and 1978 the IQ in the US had increased almost 14 points.
But in 2018, a group of Norwegian scientists discovered that as of the 1970s the IQ had gradually begun to decrease seven points in each generation. They reached this conclusion after analyzing the results of IQ tests of more than 700,000 people.
This phenomenon can be observed even in a family. It is likely that the reduction of the IQ was caused by the change in lifestyle , product of the development of technology and improvements in education. On the other hand, it may be that the old IQ test is simply incapable of assessing the intellect of a modern person.
In turn, a group of Spanish scientists carried out another investigation and measured the content of harmful substances that were in the air of 39 primary schools in Barcelona and performed an IQ test of their students. The results indicated that schoolchildren from neighborhoods with cleaner air had a better intellect.
The same conclusion came from his British colleagues at Lancaster University after having analyzed the intellect of 18,000 children. It turns out that children with cognitive disabilities live more frequently in places with contaminated air.
It is no secret that the humans of the Upper Paleolithic and the Neanderthals had a bigger brain than ours. On average, the brain volume of our ancestors exceeded 1,500 cubic centimeters compared to the current 1,425.
Several scientists believe that there is a link between the size of this organ and the level of IQ. Probably, the people of that time needed their brains to be bigger because they had to live in more hostile conditions. The Neanderthals were forced to keep in their head all the important information for life, considers the Russian anthropologist, Stanislav Drobishevski.
On the contrary, people now live in very comfortable conditions: they have clothes and food and store all the knowledge accumulated by other generations in digital media. In these circumstances, the brain, which usually consumes up to 20% energy, no longer needs to perform so many functions. This is the reason why this organ has become smaller in the last 25 years and has reduced 5% in the previous decade.
Gerald Crabtree, a Stanford University scientist, believes that in the last 3,000 years mankind has suffered at least two genetic mutations that affected intellect.
The researcher points out that the genes responsible for the intellect had optimized their work and the cognitive abilities of humans had begun to develop before our ancestors migrated from Africa.
After the arrival in Europe, life was greatly simplified. The development of agriculture, the appearance of cities, the progress of medicine reduced natural selection to almost zero. This was the cause of the birth of many individuals with mutations not so favorable in DNA.