Ratings of the “aversiveness” of the behaviors in the Family Interaction Coding System (FICS) were obtained from 103 parents of 3-12 yr old nonproblem boys. Mean ratings of this sample were highly correlated with mean ratings of the FICS obtained in 4 other studies. The ratings were used to create parent-derived positive, neutral, and negative behavior composites of the FICS codes and a total behavior score consisting of a weighted sum of these composites. The negative behavior composite closely matched the Total Aversive Behavior (TAB) composite derived by researchers in other studies. Composite scores of in-home behavior rates of 5 groups of boys (65 social aggressors, 34 stealers, 20 abused boys, 32 low-rate boys, and 71 nonproblem boys) were compared. All parent-derived composite scores significantly differentiated the groups. The total, positive, negative, and TAB composites accounted for similar amounts of between-group variance.