Early Predictors of Social Anxiety in 12-Month-Old Infant Siblings of Children with Autism Spectrum Disorder

Background: Siblings of children with autism spectrum disorder (ASIBs) are at elevated risk for anxiety later in life. In typically-developing infants, heightened social fear and atypical heart activity (e.g., respiratory sinus arrhythmia, RSA) have been shown to predict later social anxiety. However, very few studies have focused on the early risk markers of anxiety in ASIBs.

Objectives: Investigate fear and RSA in 12-month-old ASIBs and low-risk controls (LRCs) to determine if early risk markers of anxiety are present.

Methods:

Participants included 28 ASIBs (M = 12.94 months, SD = 1.33 months, 75% male) and 19 LRCs (M = 12.34 months, SD = 0.72 months, 74% male). Parent-reported fear was measured via the Fear Subscale from the Infant Behavior Questionnaire-Revised (IBQ-R; Gartstein & Rothbart, 2003). Observed social fear was measured by gaze behavior during a Stranger Approach paradigm. The proportion of time spent directing gaze toward the stranger served as an index of attention to threat. The proportions of time directing gaze to the parent and time averting gaze (i.e., looking away from the stranger and the parent) were also computed. Heart activity was recorded during a baseline period and during Stranger Approach. RSA was derived for both periods and RSA Change was calculated as Baseline RSA minus Stranger Approach RSA.

Results:

Independent samples t-tests were used to examine differences in parent-reported fear, observed social fear, and RSA. The ASIBs had higher parent-reported fear, t(45) = -1.71, p = .09, with Cohen’s d = .52, indicating a medium effect size. During Stranger Approach, ASIBs and LRCs demonstrated similar gaze behavior, ts < ± 1.32, ps > .20. Groups did not differ on baseline RSA or Stranger Approach RSA, ts < ± .85, ps > .40. However, the LRCs demonstrated a greater RSA Change, t(25) = 2.58, p = .02. In ASIBs, baseline RSA was correlated with time averting gaze, r = -.51, p = .04, and RSA Change was correlated with time averting gaze, r = -.69, p = .001, and time gazing at the stranger, r = -.50, p = .08. No significant correlations between fear and RSA were observed in LRCs.

Conclusions:

Results suggest that behavioral markers observed in an experimental paradigm (i.e., behavioral fear) may not distinguish ASIBs at 12 months of age. However, parents of ASIBs did rate their children marginally more fearful than did parents of LRCs. Furthermore, ASIBs demonstrated suboptimal RSA Change in response to a stranger approach, a physiological profile associated with later social anxiety in community samples. Interesting correlations between heart activity and behavioral fear were observed in the ASIBs, but not the LRCs, supporting theories that poor physiological regulation contributes to disrupted modulation of attention and may be linked to anxiety later in development. In all, these findings suggest that individual differences in physiology and fear may be interacting in ASIBs to confer later risk for anxiety. Future studies should examine the longitudinal effects of such factors as they relate to anxiety outcomes in ASIBs.