Slide showing column diagram displaying 'Amount of ability (at I.Q. 130) and of opportunities for higher education in the category of Manual Workers compared with all the other categories added together.' Slide shows black and white column diagram displaying 'Amount of ability (at I.Q. 130) and of opportunities for higher education in the category of Manual Workers compared with all the other categories added together.' The diagram comprises of two sets of colums, 'A,B,C,D' and 'E', with 'Ability' as a white block, and 'Opportunity' as a black shaded block. Title below image reads: 'Fig. 2. Amount of ability (at I.Q. 130) and of opportunities for higher education in the category of Manual Workers compared with all the other categories added together (Excluding F). A. Employing and Directive classes. B. Professional occupations. C. Minor professional and other highly skilled occupations. D. Clerical and commercial employees. E. Manual workers.' Late 19th to early 20th century