Carl’s paper said “most QTL effects may be much smaller than expected—not just 1% effect sizes but perhaps effects as small as .1%”.
That is fine and surely perfectly expected. Most genes have little or nothing to do with intelligence—and so can be expected to have small effects on it.
The paper didn’t say there were no larger effects caused by genetic variation. Genes associated with Fragile X syndrome, Tay-Sachs disease, Neurofibromatosis, etc are known to have larger effects.
Carl’s paper said “most QTL effects may be much smaller than expected—not just 1% effect sizes but perhaps effects as small as .1%”.
That is fine and surely perfectly expected. Most genes have little or nothing to do with intelligence—and so can be expected to have small effects on it.
The paper didn’t say there were no larger effects caused by genetic variation. Genes associated with Fragile X syndrome, Tay-Sachs disease, Neurofibromatosis, etc are known to have larger effects.