the summer before the participants entered kindergarten (at approximately 5 years of age), and follow-ups have been conducted annually and remain on-going. Approximately 485 subjects continue to participate regularly in CDP assessments. Participants who continue involvement in the CDP are from backgrounds characterized by slightly higher SES than are attrited participants, but the continuing participants do not differ from attrited participants on initial child adjustment or other family background characteristics (Pettit et al., 1997).
