In 1961, the late Sir Cyril Burt published a paper entitled “Intelligence and social mobility” that attracted two sorts of criticism. The first came from contemporary sociologists, who treated the model and data of the paper as a contribution to the debate (1) on the heritability of intelligence, and (2) on the role intelligence can play in explaining the flows of men among classes. The second, much later, criticism was voiced by Dorfman (1978), who impugned the data. In fact, a close reading of the paper makes it clear that some of the most important pieces of data were little more than guesswork by the author. Writing (it would appear) before Dorfman's comments were published, Burt's biographer says of this paper:

It should be clear by now that the Scottish Mental Survey lies at the opposite extreme from Burt's method of assembling data, and so it affords us an opportunity to substitute for his dubious analysis one that is much more securely based. To do this, however, it is necessary to engage in a conceptually more sophisticated exercise than the fairly crude analysis of the preceding chapter.