Adaptive behavior in toddlers under two with autism spectrum disorders.

Paul et al. (2014) watched toddlers under age two who had autism or other delays. They used the Vineland test to score daily living, talking, and social skills. Each child with autism was paired with a child who had the same age and overall delay but no autism.

The goal was to see which daily skills looked different, even when kids were matched closely.

Kids with autism scored lower on every Vineland area. The biggest gaps were in understanding words and doing self-care tasks like feeding and dressing. These gaps stayed even after tight matching.

Jain et al. (2025) later saw the same pattern in older children. They compared autism with social communication disorder and still found the largest Vineland gaps in communication and daily living. Together the two studies show the gap starts early and stays.

Klin et al. (2007) looked at higher-IQ school-age kids with autism. They found the Vineland-IQ split grows as kids get older. Rhea’s toddler data now anchor this line: adaptive lag begins before two, then widens.

Richler et al. (2007) also studied matched toddlers and found repetitive sensorimotor acts, not adaptive scores, best split ASD from DD. The two papers sit side-by-side: one shows behavior red flags, the other shows daily-skill red flags. Use both.

If you test a very young child, do not skip the Vineland. Even before the second birthday, low receptive language and daily-living scores can point to autism even when overall delay looks the same. Add these domains to your intake and share the numbers with early-intervention teams so self-care goals start right away.