Jumping to conclusions: Implications for reasoning errors, false belief, knowledge corruption, and impeded learning

In schizophrenia research, patients who "jump to conclusions" in probabilistic reasoning tasks tend to display impaired decision-making and delusional belief. In five studies, we examined whether jumping to conclusions (JTC) was similarly associated with decision impairments in a nonclinical sample, such as reasoning errors, false belief, overconfidence, and diminished learning. In Studies 1a and 1b, JTC was associated with errors stimulated by automatic reasoning, oddball beliefs such as conspiracy theories, and overconfidence. We traced these deficits to an absence of controlled processing rather than to an undue impact of automatic thinking, while ruling out roles for plausible alternative individual differences. In Studies 2 and 3, JTC was associated with higher confidence despite diminished performance in a novel probabilistic learning task (i.e., diagnosing illnesses), in part because those who exhibited JTC behavior were prone to overly exuberant theorizing, with no or little data, about how to approach the task early on. In Study 4, we adapted intervention materials used in schizophrenia treatment to train participants to avoid JCT. The intervention quelled overconfidence in the probabilistic learning task. In summary, this research suggests that a fruitful crosstalk may exist between research on psychopathology and work on social cognition within the general public. (PsycInfo Database Record (c) 2021 APA, all rights reserved).