Increasing the happiness of individuals with profound multiple disabilities: replication and extension.

A multielement design was used to compare the effects of three treatments on the happiness of 3 individuals with profound multiple disabilities. The conditions were typical programming using materials selected by staff, presentation of preferred materials plus social interaction, and social interaction alone with no materials present. Both the presentation of the preferred items with social interaction and social interaction alone resulted in higher happiness indicators than typical programming. The combination of preferred items and social interactions was somewhat superior to social interaction alone.