Could one life choice hold the secret to lasting intelligence gains?
Each extra year in school gives a person between 1 and 5 extra IQ points.
The effects of extra schooling are so strong, they are still measurable when people are in their 70s and 80s.
It is well-known that intelligence and education are linked.
However, it has been difficult to prove that education causes higher intelligence.
The alternative is that more intelligent people just tend to stay in education longer.
Dr Stuart J. Ritchie, the study’s first author, said:
“Our analyses provide the strongest evidence yet that education raises intelligence test scores.
We looked at 42 datasets using several different research designs and found that, overall, adding an extra year of schooling in this way improved people’s IQ scores by between 1 and 5 points.”
The research took advantage of ‘natural’ experiments to reach the conclusion that education does cause higher intelligence.
For example, in the 1960s Norway increased the amount of compulsory education by two years.
The researchers then compared people either side of the cut-off to see how it affected their IQ.
Dr Ritchie said:
“The most surprising thing was how long-lasting the effects seemed to be, appearing even for people who completed intelligence tests in their 70s and 80s.
Something about that educational boost seemed to be beneficial right across the lifespan.”
Many other different types of studies were included in the meta-analysis, which contained over half a million participants from 42 data sets.
Dr Ritchie said:
“A crucial next step will be to uncover the mechanisms of these educational effects on intelligence in order to inform educational policy and practice.”
The study was published in the journal Psychological Science (Ritchie et al., 2018).
