Category-specificity refers to a person showing sexual arousal to the categories of people they prefer to have sex with. Sexual arousal studies involving category-specificity look at genital responses (physiological changes), as well as subjective responses (what people report their arousal levels to be). Category-specific sexual arousal is more commonly found amongst men than women. Heterosexual men experience much higher genital and subjective arousal to women than to men. This pattern in reversed for homosexual men.
Studies have found that women have a non-category-specific genital response pattern of sexual arousal, meaning their genital responses are only modestly related to their preferred category. On the other hand, female subjective responses are category-specific, because they typically report their highest level of arousal to their preferred stimulus, although the reported difference in levels of arousal is typically much smaller than those in men. A possible explanation for the non-category specific genital arousal in women, which also accounts for their high individual variation, is the "preparation hypothesis". This hypothesis suggests that, provided there is enough of an increase in vaginal blood flow for vaginal lubrication to occur in a sexual context, the magnitude of arousal need not be consistent. That is, the hypothesis is that vaginal lubrication can take place as a protective mechanism even in a non-preferred sexual situation, such as when sex is non-consensual.
Read more about this topic: Sexual Arousal