Reduced Positive Bias in Autistic Adults' Intelligence Self-Assessments

Judging one's own cognitive ability is a core aspect of self-reflection, yet most people overestimate their intelligence. We investigated whether autistic (n = 284, 18-77 years old) and non-autistic (n = 63, 18-76 years old) adults differ in this bias. Participants, all naïve to prior IQ testing, completed a brief online cognitive test and provided self-estimates of intelligence. Across groups, self-estimates modestly correlated with test scores (r = .33). Nearly all non-autistic participants (93.6%) overestimated their ability, whereas autistic participants were more divided: 75.7% overestimated and 24.3% underestimated, yielding a weaker positivity bias overall. This suggests two distinct forms of inaccuracy: a systematic positivity bias in non-autistic individuals versus more variable, sometimes unduly negative self-views in autistic individuals. These could be shaped by stereotypes or social experiences and/or a result of general metacognitive imprecision. These findings highlight both reduced ego-enhancing bias and an overlooked vulnerability, offering a nuanced view of autistic self-perception.Lay AbstractUnderstanding how people judge their own intelligence can tell us a lot about self-confidence and self-perception. In this study, we explored the possible differences between autistic and non-autistic adults in this area. The study included 284 autistic and 63 non-autistic participants, all aged between 18 and 77 years. We removed any participants who reported taking an IQ test in the past to get a more authentic idea of what they thought of themselves and avoid any bias from potentially unreliable online tests. Everyone first rated how intelligent they believed they were and then completed a short online cognitive test capturing the different facets of intelligence. Overall, people's self-estimates were only moderately related to their actual test scores. The vast majority of non-autistic participants (almost 94%) overestimated their intelligence. Autistic participants showed a different pattern: While the majority (about 76%) also overestimated their intelligence, nearly one in four underestimated it. This means that non-autistic adults tended to show a very strong and consistent "positivity bias"-a common tendency to see oneself in a more favorable light. Autistic adults, however, showed more variation. Most still overestimated their abilities, but others judged themselves harshly relative to their actual performance. The weaker overall self-enhancing bias seen among autistic adults could be seen as a strength, in that it could allow a more realistic self-assessment. However, it could also translate into vulnerability, especially given the finding that autistic individuals showed overly negative self-perceptions more frequently, which could reflect the impact of stereotypes, social experiences, or difficulties with judging their own performance. Overall, the results offer a more nuanced picture of how autistic adults view their own intelligence and highlight often-overlooked vulnerabilities in self-evaluation.