Variability in Verbal and Nonverbal Communication in Infants at Risk for Autism Spectrum Disorder: Predictors and Outcomes.

The team tracked babies who had an older sibling with autism. These babies have a higher chance of autism themselves.

Parents filled out short checklists when babies were six months old. Trainers later tested gestures and understanding of words every few months.

The study ran until each child reached three years. A clinician then gave or ruled out an autism diagnosis.

Most babies gained new gestures and words at steady rates. Babies later diagnosed with autism learned the slowest.

Early parent answers at six months already pointed toward the slow-growth group.

Gordon et al. (2015) counted gestures at 12-15 months and saw the same link: fewer gestures forecast later autism and language delays. Their work is a near copy of the current results, just taken a bit later in life.

Veness et al. (2012) showed that gesture scores at 12 and 24 months clearly separate autism from other delays. The new study fills the gap by showing the downhill path starts before the first birthday.

Garrido et al. (2017) found that vocal sounds at 14 months did not predict autism. That looks like a clash, but the difference is method and age: the current paper used parent report at six months, not sound counts at 14 months. Both can be true; early parent impressions matter more than late sound tallies.

Brignell et al. (2024) followed verbal children to age 11 and found that slow starters can speed up later. The infant slow track does not lock in lifelong delay; it just signals the need for early help.

You can start watching at six months. Ask parents simple questions like “Does your baby look when you point?” If answers worry you, schedule gesture checks every few months. Early alerts let you begin turn-taking games, joint-attention routines, and parent coaching before the first birthday, when brain circuits are most open to change.