Early Gesturing As a Screener of Subsequent Language Ability in Infants at Risk for Autism Spectrum Disorder

Background: Siblings of children with autism spectrum disorder (ASD) are at a heightened risk for displaying ASD-like traits in early childhood and have an increased likelihood of developing this disorder (Constantino, Zhang, Frazier, Abbacchi, & Law, 2010; Ozonoff et al., 2010). Research on high-risk infants has found delays in understanding speech, producing vocalizations, or communicating through gestures at as early as 12 months (Mitchell, et al., 2006; Ozonoff, et al., 2010; Paul, Fuerst, Ramsay, Chawarska, & Klin, 2011).

Objectives: We examined parent report of infant gesturing at 12 months and its ability to predict language ability at 36 months for at-risk and typically developing (TD) siblings. We aim to determine if an easily accessible, cost-effective parent measure of gesturing is significantly associated with later language ability in at-risk infants.

Methods: The 126 participants included in this analysis were part of a longitudinal study of infants with an older sibling either with ASD (HRA; n=68) or without (LRC; n=58). Twelve siblings were diagnosed with ASD at 36 months based on the Autism Diagnostic Observation Schedule (ADOS) and clinical confirmation and were excluded from group difference analyses. We conducted an independent samples t-test to examine the differences between HRA and LRC on scores of gesture usage at 12 months using parent report scores from the MacArthur-Bates Communicative Development Inventories (MB-CDI), and receptive and expressive language at 18, 24, and 36 months using the Mullen Scales of Early Learning (MSEL). A partial correlational analysis was conducted to examine the association between parent-reported 12-month infant gesture, and 36-month language ability, controlling for 36-month nonverbal intelligence.

Results: Results were significant for early, late, and total gestures at 12 months (Early: t(112)=3.82, p<.001; Late: t(112)=2.55, p=.01; Total t(112)=3.29, p=.001). Results were also significant for expressive language at 24 and 36 months (24 months: t(88)=3.32, p=.001; 36 months: t(60)=2.20, p<.05), and receptive language at 18 and 24 months (18 months: t(106)=4.10, p<.001; 24 months: t(88)=3.64, p<.001). This indicates that HRA produced fewer gestures than LRC at 12 months, produced fewer sounds, words, and phrases at 24 and 36 months, and understood fewer words throughout the first two years of life. Additionally, we found that 12-month gesturing ability was associated with subsequent language ability at 36 months (r=.40, p=.02) in HRA infants, but not LRC (r=.10, p=.53).

Conclusions: We concluded that in at-risk infants, 12-month gesturing ability is associated with 36-month language ability, even when controlling for nonverbal intelligence. When examining TD infants, gesturing was not significantly associated with later language. This finding is inconsistent with previous research on TD siblings and could be due to LRC parents not being as cognizant of their child’s gesturing ability. It is now clear that parent report measures of infant gesturing are associated with language ability at up to three years in high-risk populations. These results indicate that delayed gesturing may be easily identified through parent report measures. Clinicians should screen parents for these delays within the first year of life so that interventions can be implemented before symptoms manifest fully.