Educational attainments are seen as the link between the status attainments of one generation and those of the next. Most of the apparent opportunity inequalities are thought to reside in those processes leading to the social origins - educational attainment relationships -- that is, in families, in schools, or in both. The present investigation develops a causal model to represent these social processes and to consider how teacher prophesies may explain this relationship and how they can contribute to the inheritance of inequality. The model is designed to elaborate traditional notions about the nature of teacher expectations themselves, to examine the effects on these expectations on two measures of student achievement, and to examine the extent to which student social origins affect the development of teacher expectations, and, through these, student achievement. Results offer no support to revisionist arguments that see teacher prophesies as transmitting the effects of students' social origins to their academic achievements. Teachers appear to engage in another kind of discrimination - that is, although their prophesies for both the cognitive and normative performances of students appear to have minor effects at best on what students actually learn, these same prophesies are fulfilled when teachers evaluate this learning. The social class achievement relationship persists because of social class differences in "merit". (Author/AM)