Pragmatic Language Differences between Boys and Girls with Autism Spectrum Disorder: A Cross Cultural Comparison.

Background: Autism Spectrum Disorder (ASD) is a highly heterogeneous condition that traditionally has been defined by its maleness: both in describing the “extreme maleness” of its characteristics, and in the decidedly male ratio of diagnosis (Fombonne, 2007). However, the assumption of ASD as inherently male may overlook an alternative expression of ASD more common in, or specific to, women and girls. Some research suggests that girls with ASD may demonstrate a social advantage over boys, akin to that observed in typical development (Head, McGillivray, & Stokes, 2014).

Pragmatic, or social language, deficits have been observed across the autism spectrum, and sub-clinically, in family members of those with ASD (Landa et al., 1992). While pragmatic language differences are observed in healthy men and women, sex differences often have not been detected between mothers and fathers of children with ASD (Landa et al., 1992; Klusek, Losh & Martin, 2014). Little is known about potential sex differences in the pragmatic functioning of children with ASD.

Objectives: To explore gender differences in autism symptoms, focusing on pragmatics. To determine whether differences are consistent across cultures.

Methods: Fifty-three children with ASD (30 girls), aged 9-16 years ( M= 11.86, SD= 1.60), were recruited from the United Kingdom and Ireland; 34 (9 girls), aged 8-12 years (M= 8.94, SD= 1.27) were recruited from the US. Samples were compared on ADOS items, and on pragmatic ability from examiner ratings of conversation samples using the Pragmatic Rating Scale for School-Age children (PRS-SA; Landa, unpublished).

Results: Recruitment and coding are ongoing; additional data will enhance existing sample (N=87) results, reported here. One-way between-subject ANCOVAs, controlling for nonverbal IQ, indicate similar sex differences in total PRS-SA scores, across the US and UK/Ireland samples. In the US sample, PRS-SA scores were significantly higher for males (M = 18.00, SD= 7.10, p = .01) than females (M = 9.44, SD = 4.30), indicating more pragmatic errors in males. Likewise in the UK/Ireland sample, (F (1, 49) = 3.57, p = .028), girls (M = 11.18, SE= 0.80) displayed significantly fewer pragmatic errors than boys (M = 13.79, SE = 0.84). Interestingly, nonverbal intelligence and pragmatic language errors were negatively related in boys, but not girls (Figure 1). In the UK/Ireland sample, girls (M = 15.33, SE = 1.32) displayed significantly lower ADOS total algorithm scores than boys (M = 22.82, SE= 1.55), (F (1, 49) = 12.88, p = .001), signaling fewer or less severe social-communication deficits and/or repetitive behaviors/restricted interests. Additionally, boys scored significantly higher (p < .05) on particular ADOS items (e.g., Excessive Interest, Compulsions, Conversation and Unusual Eye Contact).

Conclusions: Findings suggest similar sex differences on pragmatic errors in both cultures, with pragmatic ability possibly linked to nonverbal intelligence in boys with ASD. Also, sex differences on social-communication and repetitive behaviors/restricted interests are present on UK/Ireland sample ADOS scores. Implications for earlier identification and services for girls with ASD are discussed.