And just because a study finds a p-value of <.05 doesn't mean that it is meaningful information. There is probably some meaning behind these genes, but it's not close to explaining why there is such a great deal of normal variation in intelligence. We've found many very meaningful SNPs, but not intelligence SNPs. There is much work left to be done; so far genetic intelligence seems complicated.
Variation in a trait often means that it is not uniformly strongly selectively favoured.
Link.
"Razib Khan has an academic background in the biological sciences, and has worked for many years in software. He is an Unz Foundation Junior Fellow. He lives in the western United States."
Razib's writings can be found on his blog, Gene Expression.