Many variables have been employed in attempts to explain the movement of men through the stratification system. But the great majority of inquiries, being retrospective rather than prospective in nature, have been unable to throw any light on the simple formula for meritocracy as it was given by Michael Young (1958) in The rise of the meritocracy: IQ + effort = merit. Young's book was, of course, a satire, but its formula encapsulates very neatly an ideal that lay behind the reorganization of British education after World War II. This reorganization, with its emphasis on the IQ term of the formula, seemed to many to follow from the current socialist slogan “From each according to his ability, to each according to his needs.” The kernel of Young's satire was to show how unsocialist equality of opportunity can appear when merit is made an excuse for the enlargement of inequality.

To what extent was the ideal realized? The 1947 Scottish Mental Survey enables us to examine the first element of the formula with a high degree of precision, since a standard intelligence test, the Terman–Merrill revision of the Stanford–Binet, Form L, was administered to every one of the 590 boys in the six-day sample. Details of the results are reported on pages 15ff. The other term of the meritocratic formula – namely, effort – is not available in so unequivocal a manner as IQ, but we do have assessments of the boys' characters made by people who were in a good position to make a judgment.