Making a choice between alternatives can influence our subsequent evaluation of the selected option (e.g. Sharot, Velasquez & Dolan, 2010). Thus, in resolving psychological uncertainty, the act of making a judgment itself appears to have a constructive role in subsequent related decisions. This study focuses on emotional ambivalence and the development of affective evaluations over two stages, such that (just) making an intermediate evaluation in the first stage is shown to influence the overall affective evaluation in the second stage. Models based on classical probability theory, which assume that an intermediate evaluation simply reads off an existing internal state, cannot accommodate this result in a natural way. An explanation is offered with a quantum probability model, which, under specific circumstances, requires the measurement of an internal state to have a constructive role. The predictions of the quantum probability model were supported by the empirical results.