Influence of Race and Ethnicity on Broader Autism Phenotype Ratings of Mothers and Fathers from the Simons Simplex Collection

Background: In simplex families, broader autism phenotype (BAP) traits tend to differ by parent sex and BAP measure (Davidson et al., 2012). Except for one study indicating no differences in BAP traits between minority and non-minority parents (Sasson et al., 2013), there are no studies analyzing BAP presentation across multiple races or ethnicity. Diagnostic rates of autism in children are shown to differ by race and ethnicity (Jo et al., 2015). Revealing similar differences in parent BAP traits may provide insight into the racial and ethnic disparities observed in the diagnosis of autism.

Objectives: This study examines whether BAP ratings of mothers and fathers of a child with autism differ by their race or ethnicity.

Methods: BAP traits were examined in 2,479 mothers (9.2% Hispanic, 4.5% Black, 5.6% Asian) and 2,516 fathers (8.1% Hispanic, 5.4% Black, 4.8% Asian) who had a single child with autism in the Simons Simplex Collection (SSC). BAP traits were measured using self-reports (Broader Autism Phenotype Questionnaire (BAPQ)), other parent ratings (Social Responsiveness Scale: Adult Research Version (SRS: ARV)), and clinical interviewer ratings (Family History Interview - Impressions of Interviewer (FHI-IoI)). BAP ratings of mothers and fathers were compared across ethnicity (Hispanic vs. Non-Hispanic) and race (White, Black, and Asian) for each measure.

Results: Regarding ethnicity, Hispanic mothers (M=32.89, SD=21.95, n=252) and fathers (M=33.24, SD=25.37, n=220) had significantly higher SRS ratings than Non-Hispanic mothers (M=29.28, SD=20.24, n=2,483) and fathers (M=29.51, SD=22.29, n=2506, p’s<.05). However, Non-Hispanic fathers had significantly higher BAPQ aloofness, overall BAPQ, and FHI-IoI ratings than Hispanic fathers (p’s<.05). Regarding race, Asian mothers (M=2.60, SD=.75, n=138) were significantly higher than White mothers (M=2.37, SD=.78, n=2210) on BAPQ aloofness (p=.003), while Black mothers (M=2.44, SD=.73, n=111) were not significantly different from either. White fathers had higher BAPQ domain and overall scores compared to Black fathers, while Asian fathers had significantly higher BAPQ pragmatic scores compared to Black fathers, but significantly lower BAPQ rigidity scores compared to White fathers (p’s<.05). Both Asian mothers and fathers were significantly less likely to have ASD traits based on the FHI-IoI compared to the other two groups (p’s<.05). While BAP ratings were generally correlated, the FHI-IoI was not correlated with other measures for mothers and fathers in the Hispanic and Asian groups (p’s>.05).

Conclusions: Overall, BAP trait differences were observed across race and ethnicity, which varied by measure. Generally, White fathers tended to have more BAP traits compared to others, which could be due to a higher prevalence of autistic traits in White males or an artifact of norming BAP measures on predominantly White male populations. Furthermore, other parents rated Hispanic parents higher on BAP traits, while clinical interviewers rated Hispanic and Asian parents lower. Such differences may be due to cultural biases in others’ ratings or actual differences in BAP presentation by race and ethnicity. These findings caution against using a single measure to capture BAP traits (Davidson et al., 2012). More research is needed to determine whether current BAP measures accurately assess for traits in minorities.