Antisocial behavior by young adults is more likely for those who had a diagnosis of conduct disorder as children, particularly if they also had attention deficit hyperactivity disorder (ADHD). Biologically, antisocial behavior is predicted by blunted physiological responses to stimuli. Are these two predictors directly related? Herpertz et al. (p. 1100) measured the change in electrical skin conductance in response to pleasant, neutral, and unpleasant pictures in 8–13-year-old boys with conduct disorder, boys with ADHD, boys with both conditions, and healthy boys. Both groups of boys with conduct disorder showed less physiological response than the ADHD-only and healthy boys, regardless of the type of picture. This hyporesponsiveness suggests a problem in cognitive-emotional associations among children with conduct disorder. The boys’ own assessments of their emotional responses were misleading, since these measures showed differences for the conduct disorder groups only on the unpleasant pictures.