Abstract
Prosocial behavior at school, such as helping and sharing, contributes to positive individual development, peer relations, and classroom climate. Students with intellectual disabilities (ID) may have difficulty to demonstrate prosocial behavior, but little is known about the levels of prosocial behavior and its predictors in this population. This study aims to describe the prosocial behavior of students with ID attending special needs schools and related individual (i.e., age, sex, and general functioning) and classroom level (i.e., classmates' mean prosocial behavior) predictors. School staff members assessed prosocial behavior of 1022 students with ID (69.5% boys; Mage = 11.34 years, SD = 3.73, range: 4-19 years) at the beginning and the end of a schoolyear. We found that students with ID on average demonstrated moderate levels of prosocial behavior, this was lower compared to norms of typically developing students. Correlations within each timepoint proved that prosocial behavior was more present in older students, girls, and students with higher general functioning. Using a longitudinal multilevel model, we found that, prosocial behavior increased more over the schoolyear in older students and in students with higher general functioning. Classmates' mean levels of prosocial behavior did not affect later individual prosocial behavior. We conclude that prosocial behavior in students with ID depends on several individual characteristics, but less on the levels of prosocial behaviors in their special needs classroom peer context.