People have done IQ vs genetic variation in GWAS. They find that there is almost no impact of common variants on IQ.
Example:
>A genome-wide polygenic score constructed from the GWA results accounted for 1.6% of the variance of intelligence in the normal range in an unselected sample of 3414 individuals, which is comparable to the variance explained by GWA studies of intelligence with substantially larger sample sizes.
Example:
>A genome-wide polygenic score constructed from the GWA results accounted for 1.6% of the variance of intelligence in the normal range in an unselected sample of 3414 individuals, which is comparable to the variance explained by GWA studies of intelligence with substantially larger sample sizes.
https://www.ncbi.nlm.nih.gov/pubmed/29731509