Statistical reports of federal and state agencies usually make dull reading. One may recall numerous reports from the New York and Massachusetts State Departments of Mental Hygiene which quote a lot of figures to prove that the rural population is either better or worse off than the urban population, that there is some difference between native born of foreign parents and foreign born of native parents, and that the negro is always in worse shape than the white. In this monograph, however, there is a certain departure from the traditional objectivity which usually is a screen for the lack of scientific imagination. The authors of this monograph are the statisticians in the New York State Department of Mental Hygiene and their conclusions are interesting and sound. Their study was financed by a generous philanthropic foundation, and it