When schizophrenia and autism, for example, turned out to be largely heritable, we no longer blamed these disorders on cold or inept mothers. But, for such freighted traits as intelligence, liberals remained understandably anxious and continued to insist that differences—not just on a group level but on an individual one—were merely artifacts of an unequal environment. Conservatives pointed out that an à-la-carte approach to scientific findings was intellectually incoherent.