Maternal and paternal antisocial behavior was indexed using symptom counts for DSM-3-R (American Psychiatric Association, 1987) Antisocial Personality Disorder as assessed using the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA; Bucholz et al., 1994) when the twins were age 12. Total symptom counts were used in analyses. If only one parent’s data were available, his/her score was used (11% of sample only had mother data, 1% only had father data, and <1% were missing data on both parents). When both mother and father data were available (87% of the sample), the maximum score was used in analysis. For 53% of these participants, the maximum score was from the father, for 5% the maximum score was from the mother, and for 42% the mother and the father had the same score. Maternal symptoms ranged from 0–4 (M = 0.24), and paternal symptoms ranged from 0–7 (M = 1.10), and 5 and 51 of mothers and fathers endorsed three or more of the criteria, thus meeting Criterion A for antisocial personality disorder. Mother and father scores were positively correlated, τ = .20, p < .01.
