Accentuated environmental inequalities
Negro-white IQ comparisons usually mean comparison of an environmentally less favored group with a more favored group. When the IQ difference is in the same direction as the environmental difference, the interpretation is problematic. Gottesman (1968, p. 34) has expressed the commonly held view: 'It is only when two individuals or two groups come from equally favorable environments that a difference in measured IQ can be interpreted to indicate a difference in genetic potential.' But what about environmental inequalities that are opposite in direction to the IQ difference? Kuttner (1968, p. 147) first noted the methodological possibilities suggested by this set of conditions:
If two populations can be studied which have experienced long-standing differential treatment, and yet both achieve at the same level, then grounds exist for presuming superior potential in one group. Or ifone of the two groups responds to ameliorative conditions with a more markedly improved performance, then the same conclusion can be entertained. This procedure avoids artificially equating a disadvantaged group with a favored majority who may enjoy psychological and cultural benefits that are secondary products of status and hence beyond tabulation. At the same time, comparing deprived groups may isolate the significant variables that contribute most heavily to overall performance.