[A]n objective review of the Lynn/Vanhanen data almost completely discredits the Lynn/Vanhanen “Strong IQ Hypothesis” [“namely that IQ accurately reflects intelligence, that IQ is overwhelmingly determined by genetics, and that IQ is subject to little or no significant cultural or economic influence”]. If so many genetically-indistinguishable European populations—of roughly similar cultural and historical background and without severe nutritional difficulties—can display such huge variances in tested IQ across different decades and locations, we should be extremely cautious about assuming that other ethnic IQ differences are innate rather than environmental, especially since these may involve populations separated by far wider cultural or nutritional gaps.
We cannot rule out the possibility that different European peoples might have relatively small differences in innate intelligence or IQ—after all, these populations often differ in height and numerous other phenotypic traits. But this residual genetic element would explain merely a small fraction of the huge 10–15 point IQ disparities discussed above. Such a view might be characterized as the “Weak IQ Hypothesis”: huge IQ differences between large populations may be overwhelmingly due to cultural or socio-economic factors, but a residual component might indeed be genetic in origin.
We are now faced with a mystery arguably greater than that of IQ itself. Given the powerful ammunition that Lynn and Vanhanen have provided to those opposing their own “Strong IQ Hypothesis,” we must wonder why this has never attracted the attention of either of the warring camps in the endless, bitter IQ dispute, despite their alleged familiarity with the work of these two prominent scholars. In effect, I would suggest that the heralded 300-page work by Lynn and Vanhanen constituted a game-ending own-goal against their IQ-determinist side, but that neither of the competing ideological teams ever noticed.