title: Parent-Endorsed Sex Differences in Toddlers with and Without ASD: Utilizing the M-CHAT.
abstract: Sex differences in typical development can provide context for understanding ASD. Baron-Cohen (Trends Cogn Sci 6(6):248-254, 2002) suggested ASD could be considered an extreme expression of normal male, compared to female, phenotypic profiles. In this paper, sex-specific M-CHAT scores from N = 53,728 18-month-old toddlers, including n = 185 (32 females) with ASD, were examined. Results suggest a nuanced view of the "extreme male brain theory of autism". At an item level, almost every male versus female disadvantage in the broader population was consistent with M-CHAT vulnerabilities in ASD. However, controlling for total M-CHAT failures, this male disadvantage was more equivocal and many classically ASD-associated features were found more common in non-ASD. Within ASD, females showed relative strengths in joint attention, but impairments in imitation.
authors.affiliation: Department of Psychology, UiT - The Arctic University of Norway, PB 6050, N-9037, Tromsø, Norway. roald.a.oien@uit.no.|Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA. roald.a.oien@uit.no.
authors.forename: Roald A
authors.initials: RA
authors.lastname: Øien
authors.affiliation: Department of Psychology, UiT - The Arctic University of Norway, PB 6050, N-9037, Tromsø, Norway.|Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Logan
authors.initials: L
authors.lastname: Hart
authors.affiliation: Mental Health, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Synnve
authors.initials: S
authors.lastname: Schjølberg
authors.affiliation: Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Carla A
authors.initials: CA
authors.lastname: Wall
authors.affiliation: Center for Autism Research, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Special Needs Education, University of Oslo, Oslo, Norway.
authors.forename: Anders
authors.initials: A
authors.lastname: Nordahl-Hansen
authors.affiliation: Department of Psychology, UiT - The Arctic University of Norway, PB 6050, N-9037, Tromsø, Norway.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Eisemann
authors.affiliation: Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Chawarska
authors.affiliation: Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Fred R
authors.initials: FR
authors.lastname: Volkmar
authors.affiliation: Child Study Center, Yale School of Medicine, Yale University, New Haven, CT, USA.
authors.forename: Frederick
authors.initials: F
authors.lastname: Shic
mesh_terms: D000293:Adolescent; D001288:Attention; D000067877:Autism Spectrum Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods*; D009664:Norway; D010290:Parents; D010641:Phenotype; D011446:Prospective Studies; D012042:Registries; D012727:Sex Characteristics
keywords: Autistic traits; Behavior; Gender differences; Identification; Sex differences; m-Chat