Wide of the mark: Evidence on the underlying causes of overprecision in judgment

•We test the assumption that overprecision is due to narrow subjective probability distributions.•Subjective probability distributions are, in fact, too wide.•Findings contradict prevailing consensus on causes of overprecision.•Underprecision is reduced by experience.•Underprecision is reduced by framing the uncertainty as epistemic (vs. aleatory).