An experimental analysis of "spillover" effects on the social interaction of behaviorally handicapped preschool children.

Researchers worked with four disruptive preschool boys in a daycare classroom. Two boys got the intervention first, then the other two.

Adults gave each target boy a quick verbal prompt to play nicely. When the boy shared, helped, or talked nicely, the adult gave warm praise. No toys or tokens were used.

Prompts plus praise quickly doubled each target boy’s friendly actions and cut negative acts in half.

The gains spilled over. Untreated peers also played nicer. Even the later-target boys improved before their turn started.

Rosenfeld et al. (1970) saw the same spillover in second grade: praising one boy’s on-task work lifted the adjacent kid’s work too. The 1976 study shows the effect works for social skills at the younger age.

Jason et al. (1985) and Lowe et al. (1995) later switched from adult praise to peer-mediated play. They kept the spillover but added maintenance and generalization. The method changed; the social gain pattern stayed.

Leung et al. (2014) looked like a contradiction: their preschool social skills only spread after teachers were briefed. The key difference is planning. Bondy et al. (1976) got lucky spillover; Leung et al. (2014) programmed it by telling teachers the exact targets.

You can boost the whole room by reinforcing just two kids at a time. Start with the most disruptive pair, give quick prompts, and praise every friendly move. Watch if the positive wave reaches peers; if not, follow Leung et al. (2014) and brief staff on the specific goals.