The influence of child-based factors and parental inputs on expressive language abilities in children with autism spectrum disorder.

Song et al. (2022) watched preschoolers with autism for nine months. They asked: what predicts who will grow fastest in expressive language?

The team tested IQ, autism traits, parent talk, and the child’s own starting words. They tracked who gained new words each month.

Only the child’s baseline expressive language mattered. Kids who already had more words at the start added words the fastest.

IQ scores, autism severity, and how much parents talked did not predict growth. Early language level was the single driver.

The result lines up with Rose et al. (2020). That study also found child responsivity—like looking at AAC pictures—beat IQ as a predictor.

It also echoes Gabriels et al. (2001) and Laister et al. (2021). Both showed that early motor imitation and gesture use, not IQ, forecast later spoken words.

Li et al. (2023) seems to disagree. They found gross motor, not expressive language, predicted later autism traits in infants. The clash fades when you see they studied babies and a different outcome—traits, not word growth.

Stop waiting for “higher IQ” or “milder autism” to start language work. Screen every preschooler’s current words, signs, or AAC use at intake. Build intervention around that baseline, not around test scores. The kids with the smallest vocabularies need the most turns right now.