The influence of autistic behaviours on judgments formed in a forensic context

Author: Katie Logos

Logos, Katie, 2020 The influence of autistic behaviours on judgments formed in a forensic context, Flinders University, College of Education, Psychology and Social Work

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Although it has sometimes been reported that individuals diagnosed with autism spectrum disorder (ASD) are overrepresented in the criminal justice system, such conclusions are undermined by a variety of methodological problems such as inadequate sample sizes and insufficient control over comorbid factors (Brewer & Young, 2015). While sensationalised media reporting has often provided links between ASD and criminal activity, leading to a perception that ASD individuals may be more likely to offend, these claims are unfounded (Jones & Harwood, 2009). Rather than ASD individuals being prone to criminal offending, the behavioural features of individuals with the disorder may lead to a greater likelihood of their coming to police attention and their interactions with police progressing negatively. The latter issue was the focus within this thesis.

While behavioural presentation of ASD adults is quite variable, there are a number of behaviours that are commonly associated with a diagnosis of ASD. These include gaze aversion, inappropriate or flat expression of emotion, verbal abnormalities and repetitive body movements. Importantly, these behaviours have also been demonstrated to be relied upon by observers as cues to deception, and indicative of low credibility, within various mock-juror laboratory studies. A limited number of studies have examined perceptions of ASD behaviour within a criminal context, with these studies using written information describing the offender, or presenting the ASD witness visually but unable to control for the testimony details that were freely recalled (Berryessa, Milner, Garrison, & Cho, 2015; Maras, Crane, Walker, & Memon, 2019; Maras, Marshall, & Sands, 2019).

Across three experiments I examined whether a police suspect, played by an actor who displayed a combination of common ASD behaviours, would be more negatively evaluated by participants and judged as guilty during an interview than when ASD behaviours were not displayed. Using an actor allowed for specific manipulation of the behavioural display whilst controlling for the level of detail within the suspect testimony.

Overall, the findings of the studies within this thesis showed that a suspect was evaluated more negatively when participants viewed the suspect displaying ASD behaviours compared to those who viewed the suspect displaying none of those ASD behaviours. These judgments were a function of those behaviours violating observer expectations of appropriate suspect interview behaviour, leading to more negative impressions of the suspect and a greater likelihood of a guilty verdict. This judgmental bias was present when there was other strong evidence presented (incriminating or exonerating) upon which to base decision making. However, bias was reduced when those behaviours were explained by the disclosure of an ASD diagnostic label. Labelling led to more positive impressions of the suspect compared to when there was no label and, even for those who decided the suspect was guilty, labelling led to reduced impressions of criminal responsibility. Further research is suggested to examine the effect of ASD behaviour upon evaluations and outcomes of a live interaction, using police officers as participants, and to examine evaluations of ASD adults rather than an actor displaying those behaviours.

Keywords: autism spectrum disorder, criminal justice system, non-verbal behavior, police interviewing

Subject: Psychology thesis

Thesis type: Doctor of Philosophy
Completed: 2020
School: College of Education, Psychology and Social Work
Supervisor: Neil Brewer