The Behavior Problems Index is a 28-item rating scale or parent report of child behavior developed by Nicholas Zill and James L . Petersen, based on earlier work by Thomas Achenbach (Achenbach & Edelbrock, 1981; Michael Rutter, 1970; Graham & Rutter, 1964), Sheppard Kellam (Kellam et. al., 1975), Thomas Langner (Langner et. al., 1975), the National Center for Health Statistics (NCHS, 1972), and others.