Autism and detecting verbal truth and lies: veracity decisions, cue selection, judgment confidence, and self-report reasoning.

Introduction: Assessing veracity is a consequential task across many real-world settings, since judgments about truthfulness can shape important decisions. The way in which autistic individuals experience the social world potentially shapes how they make veracity decisions. Empirical research examining veracity judgments in autistic samples is sparse highlighting a clear gap in understanding how autistic observers make real-time veracity judgments following single exposure to an unfamiliar individual. Methods: We investigated the veracity decisions of 201 autistic and 193 not autistic adults from the general population, the cues they reported attending to, and using content analysis we explored reported reasoning. To approximate one feature of some real-world judgments, participants made a real-time veracity judgment following exposure to only one video clip of an interview with a mock suspect who was being either deceptive or truthful without feedback or opportunities for comparison. Analysis: Autistic observers were 1.47 times more likely to make a truth decision than non-autistic observers and overall were 1.51 times more likely to make an erroneous veracity decision. Both groups were comparably accurate when evaluating truth-tellers. Autistic participants noted reduced detail in deceptive accounts, and despite indicating the importance of verbal behaviours, most self-reported relying more on physical behaviours to guide their decisions. Autistic participants reported greater confidence overall in their veracity judgments. Discussion: Perceived discrepancies between the interviewee's verbal and non-verbal communication were reported by many autistic participants. This may help explain an increased tendency toward truth judgments in this case, possibly resolving uncertainty by defaulting to honesty unless sufficient cues prompted a shift. Explicit, content-focused guidance regarding the diagnostic value of verbal behaviours for guiding veracity judgments may be beneficial.