A recent study by The American Academy of Child and Adolescent Psychiatry suggests that lower intellectual or behavioral challenges in girls is a likely contributor to their lower diagnostic rates than boys displaying autistic-like traits at the same equivalency. It is not clear from the research if the results are indicative of the way girls cope and adapt, or a true gender bias in diagnosis.

The study set out to investigate disparities in gender with respect to diagnosis, and elements that influence the autism spectrum diagnostic criteria in girls as opposed to boys. The research data compared 363 boys and girls between the ages of 10-12 who met the criteria for an autism spectrum diagnosis, to those who did not meet the criteria, yet measured high on the CAST (Childhood Autism Spectrum Test) for displaying autistic-like traits. 

The results further indicate that girls who meet the criteria for an autism diagnosis demonstrate a substantial amount of additional challenges than their peers who did not meet the diagnostic criteria, though measured with correspondingly high CAST scores.

^{Resources: National Center for Biotechnology Information (NCBI), US National Library of Medicine National Institutes of Health: "How different are girls and boys above and below the diagnostic threshold for autism spectrum disorders?" PubMed.gov}