In the latest issue of Journal of Mathematical Psychology, Denis Bouyssou and Thieery Marchant provide a model for subjective expected utility without preferences. Abstract:
This paper proposes a theory of subjective expected utility based on primitives only involving the fact that an act can be judged either ‘‘attractive’’ or ‘‘unattractive’’. We give conditions implying that there are a utility function on the set of consequences and a probability distribution on the set of states such that attractive acts have a subjective expected utility above some threshold. The numerical representation that is obtained has strong uniqueness properties.