Temperament is important for considering differences among diagnostic groups and for understanding individual differences that predict problematic behavior. Temperament characteristics, such as negative affectivity, effortful control, and surgency (highly active and impulsive), are predictive of externalizing behavior in typically developing…

This study examined the persistence of early emerging aberrant behavior in 13 preschool children with developmental disabilities. The severity of aberrant behavior was assessed every 6 months over a 3-year period. Teachers completed the assessments using the Aberrant Behavior Checklist [Aman, M. G., & Singh, N. N. (1986). "Aberrant…