The fathers of boys with conduct disorder showed significantly lower electrodermal responses to pictures of either emotional quality (pleasant or unpleasant) than the fathers of controls (boys without conduct disorder). In addition, the fathers reported a more aggressive, hostile, and impulsive behavioral style. Psychophysiological measurements correlated highly between fathers and sons, and fathers' autonomic responses accounted for group differences in electrodermal responses between boys. The study concludes that the high father-son correlations in psychophysiological measures raise the question of whether autonomic abnormalities may constitute a biological mediator through which the disposition for antisocial behavior is transmitted within families. The study involved 44 boys with early-onset conduct disorder and 36 healthy controls ( 8-13 years old) as well as their biological fathers. Resting heart rate and nonspecific skin conductance fluctuations were assessed as arousal measures, with electrodermal responses and heart rate changes of pictorial stimuli serving as response measures. In addition, boys and their fathers were subjected to psychometric measurements of antisocial behavior. 4 tables and 31 references