Behavior: Nurturing Intelligence

Of the nation's 6,000,000 mentally retarded children and adults, 80% have no detectable abnormality of the central nervous system. How then to explain their inadequacy?

In the bitter controversy over the reasons for low IQs, some psychologists, notably Arthur Jensen and Richard Herrnstein (TIME, Aug. 23) put the blame largely on inferior genes. Others believe that environment—especially the environment of the ghetto —is of primary importance. A recent report on the first five years of an experiment with mentally retarded mothers and their children in Milwaukee supports the latter view. It also offers...