CSA was queried in Waves 1, 3, and 4 using the questions listed in Table 1. Items relevant to sexual abuse history appeared in three different sections of the interview under different wording. A cut-off of age 15 was chosen, as questions in the Parental Discipline and Childhood Experiences section of the interview referred to the period “before you turned 16.” Age at first occurrence was queried for all items endorsed. Criteria for CSA were met if any sexual abuse question in any wave of data collection was endorsed and reported to have occurred at age 15 or younger. Thirteen percent of participants (n=487) reported experiencing CSA. Mean age at first CSA experience was 8.4 (SD=4.1) years. There were 1,749 complete twin pairs in which CSA status was available for both members of the pair: 111 concordant for CSA (6.5%), 211 discordant for CSA (12.1%), and 1,427 in which neither twin endorsed CSA (81.6%).
