Methods
Participants. We recruited 666 autistic participants via the Netherlands Autism Register (NAR, https://nar.vu.nl/) and 517 non-autistic participants via the NAR as well as Prolific Academic. The autistic participants reported a formal diagnosis by an independent, qualified clinician. The non-autistic participants reported no diagnosis of autism. All 1183 participants were fluent in Dutch. NAR participants received \euro15 gift cards and Prolific Academic participant were paid £15. All participants were naïve to the purpose of the study and gave informed consent prior to the experiment. The experiment was approved by the ethical committee from the Vrije Universiteit Amsterdam (VCWE-2020-041R1) in accordance with all guidelines and regulations as specified in the Netherlands Code of Conduct for Research Integrity.
147 participants were excluded because either the demographic information, the AQ-28 data, or the ICAR data were missing. The data from another 167 participants were excluded from further analyses, since their performance on the task matched one or multiple exclusion criteria, as pre-registered in As Predicted (#102341). For precise information on the number of participants from each group excluded (and the reasons for their exclusion), refer to Supplementary Figure 1. The demographic information for the remaining 869 participants is depicted in Table 1, and the age distribution of the groups is shown in Figure 1. Note that the non-autistic sample used in this study comprises of the entirety of that in our earlier study (Jertberg et al., 2023), in addition to later recruits.
Table 1: demographic breakdown by group.