Brief Report: Atypical expression of distress during the separation phase of the strange situation procedure in infant siblings at high risk for ASD.

The team watched 24-month-old toddlers during the Strange Situation. This is the short test where mom leaves the room and the child is alone with a stranger.

Some toddlers had an older brother or sister with autism, so they were "high-risk." Other toddlers had no family history and served as controls.

Researchers recorded every cry. They measured how long each cry lasted and how high the pitch was.

High-risk toddlers who were later diagnosed with autism had cries that were shorter and higher-pitched.

Control toddlers used longer, lower-pitched cries when upset. The difference showed up only during the separation phase, not when mom returned.

de Graaf et al. (2011) asked adults to rate the same kind of cries. Adults said the autism-bound cries sounded more odd and distressed. Gianluca et al. now show the exact acoustic reason: shorter, higher-pitched sounds.

Root et al. (2017) warns us that high-risk siblings found through baby-sibling studies are often milder and more likely to be girls than the kids who walk into our clinics. So these cry signs may not appear the same way in everyday caseloads.

Spates et al. (2013) found delayed ear-muscle reflexes in autistic toddlers. Together the two studies point to early, measurable differences in how these children process and produce sound.

You now have a quick, low-cost red flag. If a toddler you assess lets out brief, squeaky cries when separated, note it. Pair this sign with other tools before mentioning autism risk to parents. The sound clip can also help show families why you are referring them on.