A recent study of over 100,000 Norwegian men has suggested that extra schooling has a big effect on IQ in early adulthood and one extra year in school can boost IQ by 4 points.
In Norway, changes to their education system between 1955 and 1972 meant that pupils left school at 16, rather than 14. IQ tests were done by the military when men reached the age of 19 and became eligible for the draft. The results showed an ‘unusually large’ increase in average education and average IQ levels after the change to the school leaving age.
The results showed that one additional school year lead to a 3.7 point increase in IQ.
The research team from Statistics Norway point out that there is already an established link between higher IQ and more education. They also indicated that they are unsure if the results only applied to the children in the study or to all children at that time.
The researchers indicate that it was difficult to determine whether more time in school actually improved IQ levels for all children, or just those who have a naturally higher IQ level.
The researchers warn against drawing too many conclusions from the statistics, as improvements in IQ levels could also be a result of other elements of Norwegian society and education at the time. However, they do suggest that it may be possible to further improve intelligence levels during a person’s adolescence.