The Effects of a Peer-Delivered Social Skills Intervention for Adults with Comorbid Down Syndrome and Autism Spectrum Disorder.

Cody and colleagues asked adults with both Down syndrome and autism to learn social skills. Peers who also had Down syndrome served as the teachers. The method was simultaneous prompting: the peer gave the prompt and the correct answer at the same time, then faded the help.

The team used a multiple-baseline design across skills. They tracked how well the learners and the peer-teachers did each step.

Every adult picked up the targeted social skills. Gains were small to medium, but clear. The peer-teachers kept their prompting accuracy above eighty percent without extra coaching.

Storch et al. (2012) first showed that simultaneous prompting works for daily living skills in adults with severe ID. Davis et al. (2018) extends that work to social skills and adds peer mediators with the same genetic condition.

Cariveau et al. (2023) later found big, fast gains when they used the same prompting tactic with a preschooler who had Down syndrome. The adult study shows the procedure still works after the child years, but the effect size shrinks from large to medium.

Walsh et al. (2018) ran a similar multiple-baseline study with adults who had autism plus ID. They used staff-led behavioral skills training plus video and saw large improvements. Cody’s peer-led version produced medium gains, suggesting that peer delivery can work but may need more sessions or extra supports to match staff-run intensity.

If you serve adults with dual diagnoses, you now have a road map that uses their own peers as teachers. Train a peer with Down syndrome to deliver simultaneous prompts, check that they stay above eighty percent accuracy, and you can teach social skills without hiring extra staff. Start with one skill, one peer, and one learner. Measure each step, then add more skills once the first one hits mastery.