Meta-analysis of Big Five personality traits in autism spectrum disorder.
Across 14 studies, autistic people score much lower on all Big Five traits, especially extraversion, compared to neurotypical peers.
01Research in Context
What this study did
Krafft et al. (2019) pooled 14 studies that gave the Big Five personality test to people with and without autism. They compared scores on extraversion, agreeableness, openness, conscientiousness, and neuroticism.
The sample covered 1,600 autistic and 1,700 neurotypical teens and adults. All studies used the same gold-standard personality form.
What they found
Every Big Five trait was lower in the autism group. The gap was largest for extraversion; autistic people scored about one full standard deviation lower.
Agreeableness and conscientiousness were also clearly reduced. The pattern held for both males and females.
How this fits with other research
Bassett-Gunter et al. (2017) looked only within autism and saw almost no male-female difference. That seems to clash with the new meta-analysis, but the two studies asked different questions. L et al. compared autistic boys to autistic girls; Jennifer et al. compared all autistic people to non-autistic people. Both can be true.
Hodge et al. (2025) help explain why girls are diagnosed later: their autism symptoms look milder. The lower extraversion found by Jennifer et al. may be one reason girls fly under the radar—quiet but not obviously odd.
Fusar-Poli et al. (2017) showed that sex differences in core autism traits mirror the general population. Jennifer’s findings line up: autistic people, like quiet neurotypical people, simply score lower on extraversion.
Why it matters
If you assess an older child or adult for autism, don’t stop at social-communication checklists. Ask about everyday personality—do they enjoy meeting new people, leading groups, or trying new activities? Low extraversion alone doesn’t mean autism, but a broad, flat personality profile can add evidence. Also, when writing reports, note that quiet, reserved behavior may be trait-based, not just social-skill deficit.
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02At a glance
03Original abstract
The present meta-analysis synthesizes the emerging literature on the relationship of Big Five personality traits to autism spectrum disorder. Studies were included if they (1) either (a) measured autism spectrum disorder characteristics using a metric that yielded a single score quantification of the magnitude of autism spectrum disorder characteristics and/or (b) studied individuals with an autism spectrum disorder diagnosis compared to individuals without an autism spectrum disorder diagnosis and (2) measured Big Five traits in the same sample or samples. Fourteen reviewed studies include both correlational analyses and group comparisons. Eighteen effect sizes per Big Five trait were used to calculate two overall effect sizes per trait. Meta-analytic effects were calculated using random effects models. Twelve effects (per trait) from nine studies reporting correlations yielded a negative association between each Big Five personality trait and autism spectrum disorder characteristics (Fisher's z ranged from -.21 (conscientiousness) to -.50 (extraversion)). Six group contrasts (per trait) from six studies comparing individuals diagnosed with autism spectrum disorder to neurotypical individuals were also substantial (Hedges' g ranged from -.88 (conscientiousness) to -1.42 (extraversion)). The potential impact of personality on important life outcomes and new directions for future research on personality in autism spectrum disorder are discussed in light of results.
Autism : the international journal of research and practice, 2019 · doi:10.1177/1362361318766571