The study follows families from the original research on physically abused schoolchildren living in New York City, including 153 out of the initial 200 families located and tested. Losses to follow-up included 21 abuse families and 15 control families that couldn't be located, with reasons such as relocation without forwarding addresses and disconnected phones. The retained sample in the follow-up had a higher percentage of males, 61%, compared to the original sample, and the lost sample was noted for having more aggressive ratings from parents, teachers, and peers during the pre-adolescent study.