An Investigation of the ‘Female Camouflage Effect' in Autism Using a New Computerized Test Showing Sex/Gender Differences during ADOS-2

Background: Autism is diagnosed more frequently in males than in females. Females with autism may have been under-identified due to a male-biased understanding of autism but also females’ camouflaging. This study presents an innovative computerized technique to objectively evaluate the nonverbal modality of communication (gestures) during two demonstration tasks of ADOS-2.  We describe a new technique allowing automated coding of non-verbal mode of communication (gestures) and offering the possibility of objective, evaluation of gestures, independently of human judgment. This technique was used during two demonstration activities of ADOS-2 (Autism Diagnostic Observation Schedule, Second Edition) and automatically measured participants’ gestures, allowing computation of a “Gestures Index” (GI). This GI was compared between males and females with autism.

Objectives: To test if females with autism have a higher GI compared to males with autism.

Methods: High-functioning Polish girls (n=16) and boys (n=17) with autism or Asperger syndrome, aged 5-10, with an IQ average or above, and with fluent speech were assessed during two demonstration activities of Module 3 of ADOS-2, administered in Polish, coded using Polish codes. Children were also assessed with Polish versions of the Reading the Mind in the Eyes and Faces Tests. Parents provided information on the author-reviewed Polish research translation of SCQ (Social Communication Questionnaire, Current and Lifetime) and Polish version of AQ (Autism Spectrum Quotient, Child).

Results: Girls with autism had a higher GI than boys with autism during two demonstration activities of ADOS-2. Girls with autism made significantly more mistakes than boys with autism on the Faces Test. Current communication skills as reported by parents on the SCQ were significantly better in boys with autism than in girls. Both girls and boys with autism had improved in their social and communication abilities during their life. The number of stereotypic behaviours only significantly diminished in boys but not girls during their life.

Conclusions: Girls and boys with autism differ on the non-verbal communication dimension. The automatic analysis of their gestures shows that girls with autism present longer and faster gestures. Girls present longer gestures in shorter time. The study raises questions about parent-report screening measures such as the SCQ. As parents are not supervised when completing the SCQ, it is unclear whether they take into consideration non-verbal communication (gestures) when they judge their children’s communication skills, or only their verbal communication. The results of the present study contribute to further understanding of the under-diagnosis of autism in girls.