Do you like cliff-hangers? Objective versus subjective need for closure in the schizophrenia spectrum

Need for closure (NFC) is a cognitive bias that has been implicated in the pathogenesis of delusions. A general population sample (N = 1465) was dichotomized into high versus low schizotypal participants and matched based on core social demographic characteristics (each n = 98). For the first time, we aimed at capturing NFC subjectively (with the NFC Scale) and objectively with a new experimental paradigm, the Ambiguous Movie Scene Task. In this task, participants viewed video scenes with either open or closed endings (i.e., high or low ambiguity) and rated their (emotional) reactions to the clips. Open endings were expected to lead to more frustration (i.e., due to increased need for closure) and to induce greater eagerness to learn about the possible resolution among those high on positive schizotypy. High schizotypal individuals displayed higher scores on the NFC Scale than low schizotypal individuals. Contrary to our expectations, high schizotypal participants did not recognize video scenes with open endings as ambiguous and were less eager to learn about a possible resolution than low schizotypal individuals. In the Ambiguous Movie Scene Task, high schizotypal individuals showed evidence of a jumping to conclusions bias rather than frustration over unresolved storylines. We found an overall stronger emotional response in schizotypal participants and overconfidence in their judgments. The NFC Scale and selected scores of the new task correlated moderately. The study corroborates earlier evidence for a dissociation between objective and subjective biases in the psychosis spectrum.