text: Malleability of social impressions of hyperactive children.
  The role of adults' social cognitions in mediating judgments of hyperactive children's medication-related behavior change was explored. Two hundred eight-eight undergraduates observed two videotaped excerpts of a hyperactive "target" boy playing a group game with two peers. Each target was taking either methylphenidate (0.6 mg/kg) during both excerpts, placebo during both excerpts, methylphenidate first followed by placebo, or placebo first followed by methylphenidate. Adults' cumulative social evaluations of the child were assessed after they viewed both video segments. Results indicated that observers combined their perceptions of the two behavior samples into composite impressions using an equal-weight averaging algorithm. Even for children whose behavior improved, adults' ratings of undercontrolled behaviors continued to meet or, in some cases exceed, research cutoff scores used to identify hyperactive children. The findings suggest that the actual behaviors of children with attention-deficit hyperactivity disorder (ADHD) play a more influential role in shaping interpersonal impressions than do perceiver social-cognitive processes such as primacy, recency, or integration biases.