Sex/gender differences in the level and variability of autistic traits: a meta-analysis of the Autism-Spectrum...

The objective of this meta-analysis was to assess the influence of sex/gender on the level and variability of autistic traits in both autistic and neurotypical samples.

A systematic search was conducted in the PubMed and EBSCOhost databases in April and May 2019 as well as September 2020. Studies were included if they contained information about mean (M) and standard deviation (SD) statistics of the Autism-Spectrum Quotient in a group with autism and typically developing participants. Calculations were performed using a random-effects model with study subgroups as the unit of analysis.

A total of 307 articles were chosen for further analysis with 634 786 participants in the studies evaluating the effect of sex/gender on the level of autistic traits and 495 840 individuals in the analyses examining the effect of sex/gender on the variability of autistic traits. Sex/gender moderated mainly the level of total autistic traits score (Q = 22.34, p ≤ .001) in that the level became higher as more males/men were included in the study but only in the neurotypical sample. The variability was higher in males/men than in females/women in the total level of autistic traits, social behaviors/social skills, communication/mindreading, attention to details/patterns, and attention switching/tolerance of change in a clinical and a non-clinical group of women (from variance =1.65, Q = 59, I ² = 61.02, τ² = 360.20 to variance = 56.69, Q = 47.19, I ² = 59.22, τ² = 8719.17). Furthermore, the impact of sex/gender on the level and variability of autistic traits was more pronounced in the neurotypical group than in the autism sample.

These findings suggest that males/men tend to display more pronounced and varied autistic traits than females/women. Further research is necessary to gain a better understanding of the scope and nature of these sex/gender differences.