A recent study conducted by Michael A. Woodley of Menie and his colleagues at the Technical University in Chemnitz has found a correlation between the continuous growth of the brain and intelligence in both British and German populations. The researchers analyzed data from multiple studies over the past century, which showed a long-term increase in brain mass in both countries. In the UK, the average brain mass increased by 52 grams in men and 23 grams in women over the last 80 years. In Germany, the increase was 73.16 grams in men and 52.27 grams in women over the last 99 years. The study also found that the intelligence quotient (IQ) increased by 0.19 points per decade in British men and 0.08 points in women, while in Germany, the increase was 0.2 points in men and 0.15 points in women.
Using a method developed by US psychologist Arthur R. Jensen, the researchers calculated the average increase in intelligence attributed solely to brain growth. They then compared these numbers to the Flynn Effect, which shows that the IQ in Western countries has been steadily increasing by an average of three points per decade since the beginning of the 20th century. The study found that a portion of the Flynn Effect can be explained by the continuous increase in brain mass. In the UK, where the IQ increase was 1.1 points per decade between 1932 and 2008, the contribution of brain mass increase was approximately 13%. In Germany, where the IQ increase was 6.1 points between 1956 and 2008, the contribution was around three percent.
According to Woodley of Menie, one of the co-authors of the study, the Flynn Effect is named after James Flynn, who was one of the first to demonstrate that the IQ in different populations increases over time. The study’s findings suggest that the continuous growth of the brain may be a contributing factor to the Flynn Effect. The research provides valuable insights into the relationship between brain growth and intelligence, which could have significant implications for future studies in this field.
