Beliefs, rational choice and Bayesian learning

People act in the light of their beliefs, yet sociological theories of acti on have been weak in explaining why people hold the beliefs they do. I prop ose a means of integrating beliefs into rational choice theory using a Baye sian learning model in which people act in accordance with the beliefs they hold about the world. By observing the outcomes of their actions they modi fy their beliefs. This approach, in contrast with many others, recognizes t hat beliefs evolve in the light of experience. The approach is applied to s how how the evolution of beliefs about the returns to effort in education c an give rise to observed patterns of class differences in educational expec tations and so to class differences in mobility chances, at least as these are mediated through educational attainment. I discuss the general issue of learning in the Bayesian approach and outline some limitations and areas o f further research.