Genetic factors may explain part of the interindividual variability in hypnotizability. A new avenue that may provide more comprehensive understanding of the phenotypic effects of genetic variations is the study of gene–trait interaction. In this study, the authors investigate the relationship of the dopamine-related COMT and the serotonin-related 5-HTTLPR polymorphisms to hypnotizability by taking individual differences in executive attention into account. Homozygosity for the COMT Met allele, putatively linked to the capability or proneness to dissociate from reality, was associated with high hypnotizability only if paired with high-attention ability. The finding can be integrated into hypnosis theory and represents a case of gene–trait interaction suggesting that investigating the effects of a gene in the context of relevant psychological traits may further elucidate gene-brain-behavior relationships.