The behavioral presentation of autistic adults in a forensic interview.

Autism diagnostic criteria, and research primarily involving autistic children, highlight verbal and nonverbal behaviors likely to manifest during social interaction that may generate unfavorable impressions of interaction partners (e.g., poor credibility, incompetence). These behaviors are thought to bias evaluations of autistic individuals, particularly within high-stakes contexts(e.g., police or employment interviews). However, the prevalence of those behaviors in autistic adults is unclear. IQ-matched samples of autistic (n = 43) and non-autistic (n = 41) adults participated in a simulated chatroom, exposed to text-based conversations about illegal hacking. Participants were then interviewed about the chatroom in a one-on-one video-recorded online interview with the researcher. We measured the prevalence of 19 verbal and nonverbal behaviors, and memory report characteristics displayed by the interviewees, and investigated differences between the diagnostic groups. Diagnosis had a strong effect on overall behavioral displays but was only associated with minor differences in individual behaviors. Three significant effects indicated greater difficulty interpreting figurative language, longer speech hesitations, and greater verbal intonation for autistic than non-autistic adults. Inter-individual variability within groups and within-individual variability across behaviors highlighted that behaviors were neither ubiquitous nor consistently displayed in combination. There was also a suggestion of more noticeable differences in the behavior of male than female autistic adults. Although minor behavioral differences were detected based on diagnosis, they included behaviors that could lead to negative outcomes for autistic individuals during high-stakes interactions. Whether more pronounced behavioral differences are detected during face-to-face interactions warrants further research.