"In the United States today, most claims regarding differences between ethnic ‘populations’ in relationship to IQ test performance are based on statistically derived data that relate to scholastic aptitude tests (e.g. Flynn, 2006). With this in mind, and acknowledging the superior educational attainment of African blacks in the United States (and elsewhere) it can thus be argued, because of their superior educational attainment levels, that they must also surmount far more in number and more difficult scholastic aptitude tests, in general, which in turn would require higher level IQs (see Gottfredson, 1998; Ostrowsky, 1999). As whites on average do not, or are unable to attain the same levels of academic achievement within these (their own!) academic institutional frameworks, they must also by the racialist thinking employed by some, possess significantly lower cogitative indices on the group level (e.g. Jensen, 1980; Gottfredson, 1986, 1998). In fact, attainment differences of these ‘grand’ magnitudes would suggest that American whites, in particular, are at a significant intellectual handicap when matched against immigrants of black African, East Indian, and East Asian descent. Incidentally, most American whites themselves are the children or grandchildren of “self-selected,” voluntary immigrants from Europe (Ogbu and Simons, 1998), and thus these trends can not be said to result from immigrant selectivity."
-- and much more here:
Lest we make too much of that, I am pretty sure that it was meant as a reductio argument. The point here is that there is no way to pre-select for "favorable" people from a group. You have to let individuals find their own outcomes.