How much does education improve intelligence?

A meta-analysis published in Psychological Science looks at how much education improves intelligence, and suggests that a year of school improves pupils’ IQ scores by between one and five points.

Stuart J Ritchie and colleagues looked at three particular types of quasi-experimental studies of educational effects on intelligence:

  1. Those estimating education-intelligence associations after controlling for earlier intelligence.
  2. Those using policy changes that result in individuals staying in schools for different lengths of time.
  3. Those using school-entry age cut-offs to compare children who are similar in age but who have different levels of schooling as a result of their specific birth dates.

Their meta-analysis comprised 142 effect sizes from 42 data sets involving over 600,000 participants. All three study designs showed consistent evidence that the length of time spent in school is associated with increased intelligence test scores (an average effect of +3.4 IQ points for one additional year of education). The third study design, age cut-off, had the largest effect size (+5.2 IQ points). The first study design showed the lowest effect (+1.2 IQ points). For policy change, the effect size was 2.1 IQ points.

Source: How much does education improve intelligence? a meta-analysis (June 2018), Psychological Science DOI: 10.1177/0956797618774253