Childhood prosperity, genes and PISA performance

The latest wave of PISA has been published and left many people wondering about the decline in many countries. Between 2022 and 2025, average reading scores fell by approximately 29 points in Denmark, 23 in Spain, 21 in Sweden, 18 in France, 16 in Finland and 15 in Germany, according to the OECD trend tables. The pattern differs by subject: science performance was stable across the OECD on average.

The latest declines raise a broader question: what predicts gains and losses in PISA scores across successive waves? Here I examine changes from 2006 to 2025, alongside persistent differences between countries. The recent downturn is the starting point for that question; explaining it specifically would require a separate analysis.

Changing immigrant composition is one possible contributor to falling national averages. Where immigrant students score lower on average, a rising immigrant share can lower the overall score even if performance within each group is unchanged. The effect depends on the country and its immigrant population. I therefore also examine non-immigrant students separately.

In “Can Genes Help Countries Get Rich?”, I examined country-level educational-attainment polygenic scores and long-run economic growth. This follow-up asks whether prosperity during childhood helps explain PISA performance. I also examine whether country-level educational attainment (EA4) polygenic scores help explain persistent differences in PISA performance, and how much of that association is accounted for by prosperity.