LAUSR

BACKGROUND Students with intellectual disabilities (ID) exhibit increased rates of problem behaviors compared to those without ID. AIMS Given the evidence of peer influence in typical development, we examined the impact of classmates' characteristics on problem behaviors of students with ID. We expected higher levels of problem behaviors in special needs classrooms will influence individual development of such behaviors. METHODS A longitudinal design with measurements at the beginning and the end of a school year was applied. Staff reported on problem behaviors of 1125 students with ID (69 % boys; age 11.30 years,SD = 3.75) attending 16 Swiss special needs schools. RESULTS The peer influence hypothesis was not supported for an overall problem behavior score. However, exploratory analyses suggested that peer influence did occur for the domains anxiety, problems in relating socially, and communication disturbances (not disruptive/antisocial, self-absorbed and other types of problem behaviors). The influence of classmates on anxiety was lower when there was more variability in anxiety within the classroom. The development of communication skills benefitted from attending a classroom that was heterogeneous in the level of communication problems. CONCLUSION Our results suggest that the influence of peers on problem behaviors in special needs schools is not universal but varies between domains and depends on classroom characteristics.