Can You Spot a Liar? Lie Detection and Mindreading Abilities in Adults with Autism Spectrum Disorder

Background: Detection of deception is of fundamental importance for everyday social life. Intuitively, the abilities to lie and detect lies are an aspect of mindreading – the ability to explain and predict behaviour in terms of underlying mental states (beliefs, desires, intentions etc.). People with diminished mindreading, such as those with autism spectrum disorder (ASD), might be at risk of manipulation and exploitation as a result of lie detection difficulties. However, surprisingly, no study to date has explored lie detection abilities in ASD.

Objectives: Given the important role accurate lie detection plays in everyday social interactions, it is important to establish lie detection abilities in individuals ASD. As such this research aimed to assess whether a) lie detection abilities relate to ASD traits/mindreading abilities in the general population, and b) whether lie detection abilities are impaired in adults with ASD.

Methods: In Experiment 1, performance among 216 neurotypical adults was assessed on a realistic lie detection paradigm. During this task, participants were shown interviews of individuals being questioned about whether they had cheated during a game they previously played. In all videos, the interviewee reports that they had not cheated. However, crucially, only half of the videos included individuals who had not cheated (truth-tellers) and the other half included individuals who had cheated and who lied about this in the interview (liars). Participants watched each video once and made a categorical judgement about whether the person being interviewed was lying or telling the truth about whether they cheated during the experiment. Participants also completed two classic test of mindreading ability (The ‘Reading the Mind in the Eyes’ task; Baron-Cohen et al., 2001, and the ‘Animations Task’; Abell et al., 2000) and a measure of autistic traits (the Autism-Spectrum Quotient; AQ, Baron-Cohen et al., 2000). In experiment 2, the same battery of tasks was completed by 27 adults with a diagnosis of ASD and 27 age-, sex-, and IQ-matched comparison participants.

Results: In Experiment 1, performance among neurotypical adults on the lie detection paradigm was significantly negatively associated with number of ASD traits, but not with mindreading ability. Moreover, in Experiment 2, lie detection was significantly impaired in adults with a diagnosis of ASD relative to comparison participants. Of particular note was the finding that participants with ASD failed to distinguish truth-tellers from liars even when “transparent” behavioural cues were emitted (i.e., when judging individuals who were “bad” liars) that allowed neurotypical participants to make highly accurate judgements.

Conclusions: The results of both experiments suggest that that people with ASD (or sub-clinical ASD traits) are poorer at detecting when someone is lying. This may leave individuals with ASD open to manipulation and future research should explore the benefits of lie detection training, to help individuals with ASD recognise signs of deception.