with the adult caretaker ≥50% time during the past 6 months, the twins and caretaker spoke English, and the twins were at least 6 years old at the time of the interview and no more than 17 years old at the time of screening. Twelve families were ineligible on the basis of language, indicating little bias. Biological mothers, biological fathers, stepmothers, and grandmothers were eligible to be interviewed as the adult caretaker. Interviews were completed with 2,063 adult caretakers (90.8% biological mothers) with a 70% response rate. When the caretaker was interviewed, both twins were interviewed 98% of the time. The caretaker classified 71% of the twins as Non-Hispanic white, 24% African American, 2% Hispanic, and 3% other groups.
