These anatomists of meritocracy were seldom egalitarians, criticising IQ tests not because they measured and classified, but because they failed to measure and classify with sufficient accuracy. Yet as the case against the 11-plus built up momentum, so an increasing number of intellectuals questioned not just the technology of measurement but the ideal of a meritocratic society. Marxists denounced psychometry as an instrument of class oppression; sociologists emphasised the numerous ways in which the environment shapes ability; and communitarians argued that relentless social mobility is incompatible with socialism. At the same time, many younger psychologists gave up defending IQ, tests and started to question many of the basic tenets of their profession.

The socialist movement has always harboured out-and-out egalitarians: people who insist that men are created equal, intellectually as well as morally; that social inequalities are the products of convention and mental inequalities the results of circumstances; and that the highest aim of the socialist movement is to restore men to their natural equality.

These arguments, which rested on a firm belief in the plasticity of man, the allimportance of social circumstances, and the omnipotence of scientific reformers, were peculiarly popular in the century or so before the publication of Darwin's Origin of Species in 1859. Based on Locke's theory that the mind is a tabula rasa, and buttressed by David Hartley's associationist psychology, this belief held out the possibility not just of social improvement but even of human perfection. Improve the circumstances and you improve man: perfect the circumstances and you perfect man. Education was naturally central to this vision.