Linguistic camouflage in girls with autism spectrum disorder

Abstract

BackgroundAutism spectrum disorder (ASD) is diagnosed more frequently in boys than girls, even when girls are equally symptomatic. Cutting-edge behavioral imaging has detected “camouflaging” in girls with ASD, wherein social behaviors appear superficially typical, complicating diagnosis. The present study explores a new kind of camouflage based on language differences. Pauses during conversation can be filled with words like UM or UH, but research suggests that these two words are pragmatically distinct (e.g., UM is used to signal longer pauses, and may correlate with greater social communicative sophistication than UH). Large-scale research suggests that women and younger people produce higher rates of UM during conversational pauses than do men and older people, who produce relatively more UH. Although it has been argued that children and adolescents with ASD use UM less often than typical peers, prior research has not included sufficient numbers of girls to examine whether sex explains this effect. Here, we explore UM vs. UH in school-aged boys and girls with ASD, and ask whether filled pauses relate to dimensional measures of autism symptom severity.MethodsSixty-five verbal school-aged participants with ASD (49 boys, 16 girls, IQ estimates in the average range) participated, along with a small comparison group of typically developing children (8 boys, 9 girls). Speech samples from the Autism Diagnostic Observation Schedule were orthographically transcribed and time-aligned, with filled pauses marked. Parents completed the Social Communication Questionnaire and the Vineland Adaptive Behavior Scales.ResultsGirls used UH less often than boys across both diagnostic groups. UH suppression resulted in higher UM ratios for girls than boys, and overall filled pause rates were higher for typical children than for children with ASD. Higher UM ratios correlated with better socialization in boys with ASD, but this effect was driven by increased use of UH by boys with greater symptoms.ConclusionsPragmatic language markers distinguish girls and boys with ASD, mirroring sex differences in the general population. One implication of this finding is that typical-sounding disfluency patterns (i.e., reduced relative UH production leading to higher UM ratios) may normalize the way girls with ASD sound relative to other children, serving as “linguistic camouflage” for a naïve listener and distinguishing them from boys with ASD. This first-of-its-kind study highlights the importance of continued commitment to understanding how sex and gender change the way that ASD manifests, and illustrates the potential of natural language to contribute to objective “behavioral imaging” diagnostics for ASD.

The Female Autism Phenotype and Camouflaging: a Narrative Review

“…This discrepancy was also associated with greater activation of the ventromedial prefrontal cortex in response to self-representation in females only . A similar result was found by Ratto Lai et al 2017 Discrepancy between self-reported autistic traits/performance on mentalising task (internal) and ADOS score (external) Lai et al 2019 Discrepancy between self-reported autistic traits/performance on mentalising task (internal) and ADOS score (external) Livingston et al 2019 Discrepancy between performance on a theory of mind task (internal) and ADOS score (external) Parish- Morris et al 2017 Discrepancy between parent-reported autistic traits (internal) and use of typical language techniques (external) Ratto et al 2018 Discrepancy between parent-reported autistic traits/adaptive behaviour (internal), and ADOS or ADOS-2 and ADI-R score (external) Rynkiewicz et al 2016 Discrepancy between self/parent-reported autistic traits (internal) and use of gesture in ADOS-2 (external) Observational/ Reflective Conceptualises camouflaging as the specific behaviours and processes (whether conscious or implicit) leading to variation in the behavioural presentation of autism Studies using this approach Operationalisation of camouflaging Cage et al 2018 Self-reported camouflaging (yes/no) Cage and Troxell-Whitman 2019 Score on self-report measure of camouflaging behaviours (CAT-Q). Cassidy et al 2018 Score on four self-report questions of camouflaging Dean et al 2017 Observed social behaviours in the playground Hull et al 2017a Self-reported behavioural examples Hull et al 2018 Score on self-report measure of camouflaging behaviours (CAT-Q).…”

“…Other discrepancy approaches have looked at specific characteristics of autistic behavioural expression. For instance, autistic females were found to use more typical patterns of filling pauses in conversation than males of equivalent autistic trait severity (Parish-Morris et al 2017). Another study found trends towards autistic girls using more vivid gestures in computerised ADOS-2 than boys, where both genders reported equivalent levels of autistic traits (Rynkiewicz et al 2016).…”

Sex differences in social attention in autism spectrum disorder

“…Greater interest and attention to social relative to nonsocial information from an early age could increase social learning opportunities and social abilities for females, leading to differences in phenotypic development compared to males with ASD. In turn, these skills could relate to under‐ or delayed identification of autism and improved “camouflaging” of characteristics seen later in development for females with ASD [Dean et al, ; Parish‐Morris et al, ]. Indeed, it is possible that the findings reported here indicate a camouflaging ability to selectively engage with social stimuli rather than being truly motivated by it.…”

Gender differences in restricted and repetitive behaviors and interests in youth with autism

“…For example, the RBQ‐2 and CRI are measures which are more sensitive to capturing RRBI in the neurotypical population and item phrasing may be less biased to ASD gender differences [Lidstone et al, ]. Inclusion of a typical sample may be useful in parsing out general gender differences versus ones that are specific to ASD [Parish‐Morris et al, ]. Finally, the use of observational measures may aid in creating more sensitive measures for girls and better capturing RRBI differences.…”