Cultural history of the buttocks desirability of buttocks: Since the early 2000s, songs about the female buttocks have proliferated, especially in the hip-hop, reggae/dancehall, and R&B genres. Buttocks are often emphasized in pornography. Patricia Hill Collins, an African-American post-modern feminist writer, theorizes that this is derived from a stereotype that black women are promiscuous, and their buttocks are objectified by pornography as a result. A buttocks fetish or buttocks partialism refers to a condition wherein the buttocks becomes a primary focus of sexual attention. It may be associated with coprophilia, panty fetishism, eproctophilia, and sadomasochistic corporal punishment involving the buttocks. "Pygophilia" refers to sexual arousal
Sexual orientation is verbal self-reporting or self-labeling, which depend on respondents being accurate about themselves. Studying human sexual arousal has proved a fruitful way of understanding how men and women differ as genders and in terms of sexual orientation. A clinical measurement may use penile or vaginal photoplethysmography, where genital engorgement with blood is measured in response to exposure to different erotic material. Some researchers who study sexual orientation argue that the concept may "not" apply similarly to men and women. A study of sexual arousal patterns found that women, when viewing erotic films which show female-female, male-male and male-female sexual activity