Gender Differences in Parent-Reported Restricted Interests in Children with and without ASD

Background: Restricted interests (RIs), a diagnostic criterion of ASD, are pursuits that are circumscribed and intense, causing interference in daily activities (Lord et al., 1993). Clinician assessments of RIs indicate a greater prevalence in boys than in age- and IQ-matched girls both with and without ASD (Anthony et al., 2013). However, the assessment of RIs may be biased towards identification in boys, particularly as the topic of girls’ interests may appear ‘typical’, despite causing significant impairment in everyday contexts (Duvekot et al., 2017; Hiller et al., 2014).

Objectives: The objectives of the current study were to: (1) identify the number of parent-reported RIs in a sample of IQ-matched children with and without ASD and (2) examine group and gender differences in interest topics and whether they cause interference in the child’s life.

Methods: A total of 125 age- and IQ-matched children (age 6-12, IQ>80) and their caregivers participated in this study (55 ASD, 41 boys; 70 typically developing [TD], 43 boys). Children were administered the Wechsler Abbreviated Scales of Intelligence 2^nd Edition (Wechsler, 2011) while their parents completed the Yale Special Interests Survey (Klin & Volkmar, 1996), a qualitative questionnaire eliciting information on the presence of intense interests and activities relating to the interest. Interference of interest was assessed as a sum of questions on a 4-point scale reporting the percentage of time spent engaging in the interest within contexts of daily living (i.e., alone, with family, with peers).

Results: Seventy-seven children were identified as possessing RIs (ASD: 34 boys, 11 girls; TD: 22 boys, 11 girls). A majority of youth with ASD were identified as having a RI (83% of boys, 79% of girls) compared to 51% and 41% of TD boys and girls, respectively. Independent samples t-tests identified that IQ was not significantly different between diagnostic groups (t(123)=1.64, p=.09) or between those with and without RIs (t(123)= -.561, p=.58). Eight of 11 ASD girls shared a similar interest to ASD boys, primarily video games and Pokémon (50%); 73% of all girls shared similar interests (animals, cartoon characters, drawing, and reading). However, despite similarities in content, the RI of girls with ASD caused significantly more interference in daily living compared to TD girls (t(19)= -2.71, p=.01, d=1.17). 58% of all boys shared similar interests; however, 43% were an obsessive interest in video games. Parent ratings of interference did not significantly differ between boys and girls with ASD (t(42)= -.78, p=.44).

Conclusions: Consistent with previous research, our results indicate that the RI topics of girls with ASD were similar to those of TD girls. However, parent-ratings of interference were significantly higher in ASD girls than TD girls, while not significantly different from those of boys with ASD. These findings suggest that interference in daily activities may be a key distinguishing feature of RI between children with and without ASD more so than the topic of interest itself. Assessment of the interference parents attribute to a RI may be a possible avenue to improving diagnostic accuracy in ASD, particularly among girls.