The study found that youths in two-biological-parent ("intact") families committed the fewest kinds of antisocial behaviors. This finding is consistent with the literature that has found overall delinquency to be about 10-15-percent higher in households without two biological parents compared with two-biological-parent families. The study also found that youths in "blended" families (youth resides with both of his/her biological parents, but has half- and stepsiblings who may or may not reside in the household) and "intact cohabiting families" (unmarried biological parents living together) were significantly more antisocial than their counterparts in "nuclear" households (two married biological parents with no half- or stepsiblings). The difference between blended and nuclear households is accounted for by a variety of structural and experiential factors, the most important of which include disadvantage related to family income, government aid, teenage motherhood, grade repetition, scholastic performance, antisocial peers, and prior antisocial behavior. The difference between nuclear and intact cohabiting households, on the other hand, tended to be explained by the family-related and school-related factors but not by peer affiliation and prior behavior. Among youths who live in one-biological-parent families, cohabitation is associated with higher risk of antisocial behavior compared with residence in stepfamilies and single-parent families. This finding was particularly strong when the biological father was the custodian. Future research should seek to identify the various factors associated both with family structure and antisocial/delinquent behavior. 4 tables and 56 references