A Polygenic Score for Higher Educational Attainment is Associated with Larger Brains

Area of Science:

• Neuroscience
• Genetics
• Cognitive Science

Background:

• Higher intelligence test scores correlate with larger brain size.
• Genetic factors are known to influence both brain size and intelligence.
• A hypothesis suggests genetics impact intelligence by promoting larger brain development.

Purpose of the Study:

• To test the hypothesis that genetics influence intelligence via brain size.
• To investigate the relationship between genetic factors, brain volume, and cognitive performance.
• To explore the mediating role of brain size in the genetic basis of intelligence.

Main Methods:

• Utilized four large imaging genetics studies with a combined sample size of 7965 participants.
• Employed polygenic scores derived from a genome-wide association study (GWAS) of educational attainment.
• Conducted a meta-analysis to assess associations between genetics, total brain volume, and cognitive test scores.

Main Results:

• Participants with higher polygenic scores for educational attainment performed better on cognitive tests.
• Larger total brain volume was associated with higher cognitive test scores.
• Individuals with higher polygenic scores also exhibited larger total brain volume.
• Brain size showed partial mediation effects between education polygenic scores and cognitive performance.

Conclusions:

• Genetic factors appear to influence cognitive performance partly through their effect on brain size.
• Integrating genome-wide association study (GWAS) data with brain imaging offers insights into the neurobiology of intelligence.
• Prioritizing population-representative samples is crucial for robust neuroscience research findings.