Psychologist James Flynn, engage in research in the field of IQ, noted that the rate of intelligence among modern people ceased to grow. The scientist, after whom was named the so-called "Flynn effect" (gradual steady increase in average IQ from year to year, said he noticed that trend has not demonstrated that mankind was to grow stupid, but can say that people have reached a certain limit mental development.

The James Flynn also noted that recent studies show that U.S. residents continue to demonstrate a trend to an increase in IQ, while in Scandinavian countries such growth stopped.