Dyadic and triadic behaviours in infancy as precursors to later social responsiveness in young children with autistic disorder.

Clifford et al. (2009) watched old home movies of babies who were later diagnosed with autism. They coded tiny moments: Did the baby look at mom’s eyes? Smile back? Follow a point?

Three to five years later they asked parents how social the same kids were. The team wanted to know if those baby clips could predict later social skills.

Early eye contact, shared smiles, and joint attention scenes forecasted later social responsiveness. The more positive dyadic and triadic clips, the stronger the social skills years down the road.

Home-video beats parent memory alone. Videos caught details moms and dads forgot.

Clifford et al. (2007) showed the same four baby behaviors can flag autism before age two. The 2009 paper moves the finish line: it links those same clips to everyday social skills years later.

Freeman et al. (2015) stretched the timeline even further. They saw that strong joint attention at age three predicts closer, calmer friendships at age eight. Together the studies draw one long arc: baby looks → preschool sharing → school-age friendship.

Papageorgopoulou et al. (2024) seems to clash. They found declining parent-infant interaction quality, not just baby cues, predicts later autism. The difference is scope: Sally’s team coded only the infant’s moves, while Eirini scored both parent and baby. Both matter; they measure different pieces of the same puzzle.

You can add brief home-video review to your early assessment kit. Ask families for five minutes of first-birthday footage. Score eye contact, shared smiles, and point-following. If these are weak, start joint-attention and social reciprocity goals now instead of waiting. It’s free, quick, and more accurate than parent interview alone.