The groundbreaking research of William Masters and Virginia Johnson in the 1960s focused scholars’ attention on human sexuality and on the various sexual dysfunctions that can occur in the couple relationship. Sexual dysfunctions can be grouped into four categories: (1) dysfunctions of sexual desire, (2) dysfunctions of sexual arousal, (3) dysfunctions of orgasm, and (4) sexual pain disorders. The cause of problems in sexual functioning can be attributed to various factors, including organic factors, such as illness (e.g., high blood pressure, cancer, multiple sclerosis, diabetes); specific medications; and alcohol and drug abuse, or physical injury or age-related deterioration. This entry focuses on psychological factors affecting human sexuality and sexual dysfunction. However, before we proceed, it should be mentioned that prior to concluding that one’s sexual ...