Advancing imitation and requesting skills in toddlers with Down syndrome.

Drawing upon information about the Down syndrome behavioral phenotype and empirically based intervention strategies, we examined intervention addressing early communication impairments in young children with Down syndrome. Intervention involved multiple opportunities, shaping, prompting, and reinforcement to address both verbal imitation and requesting. Intervention also incorporated the relative strengths in social development characteristic of the Down syndrome behavioral phenotype by focusing on a more social request prior to addressing the more impaired instrumental request, as well as incorporating social consequences. Three of the four toddlers with Down syndrome were taught verbal imitation skills, two of whom generalized to novel sounds. All four toddlers with Down syndrome acquired requesting skills in the form of gaze shifting and vocalizing; three were also taught verbal approximations of requesting words (e.g., "mm" for "more") using imitative prompts. These results contribute to the small, but growing, literature demonstrating behavior analytic interventions informed by an understanding of the Down syndrome behavioral phenotype.