Taboo refers to practices that are generally prohibited because of religious or social pressures. Some sexual behaviors have been taboo throughout history and remain so today. These include behaviors such as incest and rape, as well as many paraphilias such as pedophilia (sexual abuse of children by unrelated adults), necrophilia (sexual arousal from viewing or having sex with a corpse), and bestiality (sexual relations with an animal).

Other sexual behaviors that were once taboo no longer are, even though they may not be as approved as some other behaviors that have been accepted as "natural" or "normal."

Taboo Sexual Behaviors

Included in this category are masturbation, oral and anal sex, homosexuality, some forms of bondage, and sex with a menstruating woman. This change can in part be attributed to societies' gradual acceptance of what constitutes normal and harmless sexual experiences between consenting adults.

Incest

Incest is a behavior that is considered taboo and illegal in nearly all societies. Incest refers to any kind of sexual contact (oral, anal, or vaginal sex, fondling, or masturbation) between members of the same family. Definitions of what constitutes a family member vary, but ordinarily they include not only parents and siblings, but grandparents, uncles and aunts, nieces and nephews, step kin, and in most cases, first cousins.

The incest taboo is thought to protect families and society from the negative effects of inbreeding, once common among European royalty and in some other societies.

Bestiality and Necrophilia

Both are strong sexual taboos and forbidden by all major religions. They are considered illegal in the United States and almost everywhere else in the world.

Historically, the primary reason for opposition to these behaviors was related to the fact that they were not procreative acts.

Furthermore, sexual relations between humans and animals or corpses violated the notion that proper sex was to take place between a married couple.

In more modern times society has found both of these practices abhorrent because of the fear of spreading diseases, and because in neither case does someone wishing to practice these illegal social taboos have the willing permission of their sexual partner.