The effect of Autism Spectrum Disorder behaviours on perceived deception and credibility

Author: Alliyza Esther Qin Shi Lim

Lim, Alliyza, 2020 The effect of Autism Spectrum Disorder behaviours on perceived deception and credibility, Flinders University, College of Education, Psychology and Social Work

Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.

Abstract

Research has demonstrated the existence of a pervasive stereotype that gaze aversion and fidgeting are indicators of deception (e.g., The Global Deception Research Team, 2006). However, studies on actual markers of deception have found that, contrary to popular belief, these behaviours are unreliable cues to deception (e.g., DePaulo et al., 2003). Coincidentally and unfortunately, gaze aversion and fidgeting are also characteristic behaviours of individuals with Autism Spectrum Disorder (ASD). It is proposed that the high similarity between perceived indicators of deception and common ASD behaviours may cause ASD individuals to be more vulnerable to being judged as deceptive and non-credible compared to their neurotypical peers.

To test this hypothesis, a series of five experiments was conducted. In Experiment 1 (N = 161), Experiment 2 (N = 463), Experiment 3 (N = 423), and Experiment 4 (N = 392), participants were shown short video clips of neurotypical individuals being interviewed and asked to indicate their impression of the individual’s truthfulness or credibility. Each video either depicted one of five common ASD behaviours (gaze aversion, repetitive body movements, literal interpretation of figurative language, poor reciprocity, or flat affect), or no ASD behaviour (control condition). Despite the use of similar methodology across these experiments, there were large discrepancies in the findings of each one. Thus, to obtain a clearer overall picture of the effect of ASD behaviours on judgments of deception and credibility, a meta-analysis was conducted on the results of these four experiments. The meta-analysis revealed small but statistically significant effects of the five ASD behaviours on perceived deception and credibility.

Experiment 5 then examined whether a clinical sample of ASD individuals would be perceived as more deceptive and less credible than neurotypical controls, and if such an effect would be mediated by the degree to which they displayed each of the target behaviours. Thirty ASD individuals (and 29 neurotypical controls) were recruited to participate in video-recorded interviews, which were then shown to participants (N = 1410) who rated the perceived truthfulness or credibility of the target individual. The results revealed that ASD individuals were perceived to be more deceptive and less credible than neurotypical individuals. However, this effect was not influenced by the presence of any of the target ASD behaviours, but only by the individual’s overall presentation as having a disorder.

Taken together, the findings of this project suggest that within the current experimental paradigm, gaze aversion, repetitive body movements, literal interpretation of figurative language, poor reciprocity, and flat affect have only small effects on judgments of deception and credibility. Yet, despite this, ASD individuals were found to be perceived as more deceptive and less credible relative to neurotypical individuals. Though it is uncertain exactly why this is the case, this project is among the first to provide empirical evidence that ASD individuals may be vulnerable to biased deception and credibility judgments. Further research is necessary to investigate the underlying mechanisms by which ASD diagnosis influences perceived deception and credibility.

Keywords: autism, deception, credibility

Subject: Disability Studies thesis

Thesis type: Doctor of Philosophy
Completed: 2020
School: College of Education, Psychology and Social Work
Supervisor: Professor Robyn Young