The pattern of finding for the wave 3 conduct disorder scale mirrors those for the wave 2 conduct disorder scale; DRD2 (b = .030, p = .769) and DRD4 (b = -.023, p = .812) fail to have a significant effect on conduct disorder, but the interaction between DRD2 and DRD4 has a significant effect (b = .322, p = .039) on the wave 3 conduct disorder scale. This evidence concerns the gene DRD2 and conduction system disorder.