Fifteen Thousand Hours (Rutter et al., 1979a) has been widely described as the most encouraging educational research for teachers in years. It is said to demonstrate that schools ‘make a difference to their pupils’, that some schools, by virtue of a superior organizational ethos, assist pupils more than do other schools. This has been said to provide an antidote to, or even a refutation of, the pessimistic conclusions of earlier researchers like Jencks et al (1972), Coleman et al. (1966) and Bernstein (1970). This paper questions whether the evidence of Rutter et al. (1979a) supports their conclusions about school organization, let alone the wilder claims of other writers basing themselves on Rutter et al. Furthermore it is argued that even if the conclusions of Rutter et al. are accepted, they do not in any way contradict the major hypothesis of Jencks and others, that educational policy in modern capitalist societies can do very little to lessen social inequality.