Taboo
The anthropological approach says that taboos are the result of history and certain cultural experiences. Steven Pinker, A psychologist and writer, says that taboos have developed culturally from more basic instincts. He thinks that humans have a reflex to feel disgust when they see some things that carry disease (including dead bodies).  He says that people created taboos regarding the dead because of this natural disgust for dead bodies. He thinks that some actions can also cause this reflex of disgust. He says many people have a reflex of disgust about incest (sexual relationships between family members). For this reason, taboos about incest developed.