The Dual Control Model proposes that sexual responses involve an interaction between sexual excitatory and sexual inhibitory processes. The model further postulates that individuals vary in their propensity for both sexual excitation and sexual inhibition, and that such variations help us to understand much of the variability in human sexuality. The development of psychometrically validated instruments for measuring such propensities for men (Sexual Inhibition/Sexual Excitation Scales) and for women (Sexual Excitation/Sexual Inhibition Inventory for Women) is described. These measures show close to normal variability in both men and women, supporting the concept that "normal" levels of inhibition proneness are adaptive. The relevance of the model to sexual development, sexual desire, the effects of aging, sexual identity, and the relation between mood and sexuality are discussed, and the available evidence is reviewed. Particular attention is paid to gender differences and similarities in propensities for sexual excitation and inhibition. Research findings related to sexual problems, high-risk sexual behavior, and the relevance of this model to clinical management of such problems are also summarized. Last, ideas for future use and further development of the Dual Control Model are considered.