I did a research paper in graduate school on child IQ and much of the research at that time suggested that child IQ is largely a function of maternal IQ. Who knows?
This subject is well researched and while the implications of the results are controversial, the science behind the results is well founded. Namely, that intelligence exists, that it is both heritable and subject to environmental influences, and in roughly equal measures. Many wish to deny these results for political and other reasons. The evidence is quite conclusive and their attempt at denial makes them appear ludicrous to the knowledgeable observer. With respect to “Who knows?” see Herrnstein and Murray’s “The Bell Curve.” It is likely available at your local library. http://en.wikipedia.org/wiki/The_Bell_Curve