Stanford geneticist, butterfly specialist, conservationist, and zero-population-growth advocate Paul Ehrlich teams up with a psychologist colleague to tackle the Jensen/Herrnstein/Shockley crew. They proceed to demolish the blacksversus-whites IQ controversy by now-familiar arguments. First off, there are no biological races, only socially defined ones. Intelligence is culturally defined. IQ is culturally defined. IQ test-makers generally come from the same color and class that determine the norms. Sir Cyril Burt's twin studies have been laughed out of court, and hardly anybody else has been able. to come up with a twin or adoptive child comparison-study that satisfies statistical criteria. Heritability is undecidable. So what we have left is a comparison of groups unequally treated by a given culture, with a preponderance of poorer nutrition and less intellectual stimulation, emotional health, motivation, etc. in one of the groups. From this one can conclude nothing about innate group differences. The book makes its point. (Best example is the ""Chitling Test of Intelligence"" designed by a Watts social worker--which your average WASP would fail.) It could also be said that the book overmakes its point. Indeed, since the authors readily acknowledge that the whole question of the heritability of intelligence makes no sense, the best solution might be to stop publishing statements and rebuttals. They won't convince the loyal opposition. Focus on environment, health, nutrition, individuals, teaching. Make the argument moot.