An extra year of education can make you smarter

An extra year of schooling may leave students with new knowledge and may lead to a small but noticeable increase to students' IQ, a new study suggests.

The researchers found that an additional year of education was associated with an increase in IQ that ranged from 1.197 IQ points to 5.229 IQ points.

In combination, the studies indicated that an additional year of education correlated with an average increase of 3.394 IQ points.

"Our analyses provide the strongest evidence yet that education raises intelligence test scores," said co-author Stuart Ritchie from the University of Edinburgh.

"We looked at 42 data sets 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 one and five points," Ritchie added.

Research has long shown that years of education and intelligence are correlated but it has been unclear whether this is because education boosts intelligence or because individuals who start off with higher IQ scores are likely to stay in school for longer, the researchers said.

For the study, published in the journal Psychological Science, researchers looked at three particular types of quasi-experimental studies from a variety of sources, including published articles, books, preprint articles, working papers, dissertations, and theses.

To be included in the meta-analysis, each data set had to provide cognitive scores obtained from objective measurement with participants who were six or older and cognitively healthy.

This yielded 42 data sets from 28 studies collected from a total of 615,812 individuals, the researchers 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," Ritchie said.

The researchers also noted that each type of study has strengths and weaknesses, and the findings raise several new questions that future research will have to address.