Psychological constructivist models of emotion propose that emotions arise from the combinations of multiple processes, many of which are not emotion specific. These models attempt to describe both the homogeneity of instances of an emotional “kind” (why are fears similar?) and the heterogeneity of instances (why are different fears quite different?). In this article, we review the iterative reprocessing model of affect, and suggest that emotions, at least in part, arise from the processing of dynamical unfolding representations of valence across (...) time. Critical to this model is the hypothesis that affective trajectories—over time—provide important information that helps build emotional states. (shrink)