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

Cereb Cortex
Authors
Keywords
Abstract

People who score higher on intelligence tests tend to have larger brains. Twin studies suggest the same genetic factors influence both brain size and intelligence. This has led to the hypothesis that genetics influence intelligence partly by contributing to the development of larger brains. We tested this hypothesis using four large imaging genetics studies (combined N = 7965) with polygenic scores derived from a genome-wide association study (GWAS) of educational attainment, a correlate of intelligence. We conducted meta-analysis to test associations among participants' genetics, total brain volume (i.e., brain size), and cognitive test performance. Consistent with previous findings, participants with higher polygenic scores achieved higher scores on cognitive tests, as did participants with larger brains. Participants with higher polygenic scores also had larger brains. We found some evidence that brain size partly mediated associations between participants' education polygenic scores and their cognitive test performance. Effect sizes were larger in the population-based samples than in the convenience-based samples. Recruitment and retention of population-representative samples should be a priority for neuroscience research. Findings suggest promise for studies integrating GWAS discoveries with brain imaging to understand neurobiology linking genetics with cognitive performance.

Year of Publication
2019
Journal
Cereb Cortex
Volume
29
Issue
8
Pages
3496-3504
Date Published
2019 07 22
ISSN
1460-2199
DOI
10.1093/cercor/bhy219
PubMed ID
30215680
PubMed Central ID
PMC6645179
Links
Grant list
R03 HD050374 / HD / NICHD NIH HHS / United States
R01 AG049789 / AG / NIA NIH HHS / United States
R01 DA033369 / DA / NIDA NIH HHS / United States
K99 AG054573 / AG / NIA NIH HHS / United States
P30 AG034424 / AG / NIA NIH HHS / United States
R01 DA031579 / DA / NIDA NIH HHS / United States
MR/P005918/1 / MRC_ / Medical Research Council / United Kingdom
K01 MH099232 / MH / NIMH NIH HHS / United States
S10 OD018164 / OD / NIH HHS / United States
R01 AG032282 / AG / NIA NIH HHS / United States