Kaplan’s model of sexual response, an outgrowth of her extensive experience as a sex therapist, contains three stages: desire, excitement, and orgasm (see I Figure 6.2). Kaplan suggested that sexual difficulties tend to fall into one of these three categories and that it is possible for a person to have difficulty in one while continuing to function normally in the other two.
One of the most distinctive features of Kaplan’s model is that it includes desire as a distinct stage of the sexual response cycle. Many other writers, including Masters and Johnson, do not discuss aspects of sexual response that are separate from genital changes. Kaplan’s description of desire as a prelude to physical sexual response stands
as a welcome addition to the literature. Kaplan’s model was initially widely embraced as one that rectified a perceived deficiency in the Masters and Johnson model. However, it is now realized that simply adding a desire phase does not necessarily provide a complete model of human sexual arousal and response. One problem with assuming that desire belongs in such a model is that perhaps as much as 30% of sexually experienced, orgasmic women rarely or never experience spontaneous sexual desire (Levin, 2002). Fewer men appear to be included in this category. For example, in the NHSLS, 33% of women reported being uninterested in sex compared with 16.5% of men (Laumann et al., 1994).
It is clear, then, that not all sexual expression is preceded by desire. For example, a couple might agree to engage in sexual activity even though they are not feeling sexually inclined at the time. Frequently, they may find that their bodies begin to respond sexually to the ensuing activity, despite their lack of initial desire.