Since the early 1900s, raw scores on IQ tests. Has largely increased in most parts of the world. This phenomenon is called the “Flynn effect”. After the scientist who discovered it, James Flynn. In the 1980s, Flynn noticed that US soldiers who took IQ tests in the 1980s did much better than those who took the same test in the 1950s. After further research, Flynn found that IQ scores have increased worldwide by about 3 points or more per decade. At the same time, scientists believe this increase in IQ. This is because we have improved our ability to think logically and solve problems. And consider hypothetical situations. It may also be due to an increase in formal education. Vaccinations and better nutrition. So it can be seen that the intelligence quotient of Vietnamese people is completely different. But it also depends on many other important factors.