Preschool Peer Social Intervention (PPSI) to Enhance Social Play, Interaction, and Conversation: Study Outcomes.

Bauminger-Zviely et al. (2020) ran a six-month program called Preschool Peer Social Intervention. They mixed preschoolers with high-functioning autism and typical peers in small classroom groups.

The kids met twice a week. Activities taught sharing, pretend play, and back-and-forth talk. Researchers used a randomized design and tracked social, play, and daily-living skills.

All children in the peer groups got better at the social goals they practiced. They also showed gains in play complexity and everyday adaptive skills.

Children who stayed in regular class without the groups lost ground on some measures. The peer mix helped, not hurt.

The results line up with Moya et al. (2022). That team added caregiver coaching to PEERS for Preschoolers and saw social gains too. PPSI shows you can skip the parent class and still win when typical peers are in the room.

Harper et al. (2008) and Ashley et al. (2025) used peers to deliver PRT at recess. They also saw more social bids, but those studies were tiny and run by staff. PPSI moves the peer idea into a full RCT inside preschool centers.

Lancioni et al. (2011) ran an earlier RCT called S.S.GRIN-HFA with older kids. Both trials beat wait-list controls, showing the peer-group recipe works across ages.

You can start peer-based social skills at age four, not eight. Pick two typical classmates, rotate them into play centers, and script simple share-and-talk games. Track one social goal per child and one play level per week. No extra staff or parent nights needed.