Some people think that sadism and abuse are part of the courtship process in primitive times, and this tendency will become some manifestations of reincarnation in later generations (that is, atavism). A weak and atrophied person, in order to stimulate sexual desire, wants to cheer up with pain. But it is only a hypothesis, and there is no sufficient factual basis. At present, there are many different explanations for the causes of sadism and masochism. Regarding the formation of sadism, experts believe that it is related to several factors:

First, it may be related to childhood life experiences. Due to some factors in the family education environment, children have formed wrong cognitive stereotypes about sexual relations since childhood. At the age of 6, a male sadist had no intention of spying on his parents' sex life in the bedroom. His parents' tumbling, struggling, tearing and breathing puzzled him. Older partners told him: don't look at their pain, this is the happiest thing in life. After entering adolescence, he said from childhood and saw some descriptions of men and women fighting and making love in film and television programs, which evoked memories of childhood. This stereotype of cognition and attitude eventually developed into sadism. I hurt my girlfriend several times during my love. At that time, my girlfriend thought it was a mistake and didn't care. After marriage, he abused and hurt his wife many times. Some masochists show remorse in the process of abuse, thinking that they are sorry for the opposite sex and feel guilty, so they are willing to accept the abuse of the opposite sex to show obedience and self-punishment in pain, and combine with sexual impulses to form a masochistic tendency. Some women have to have their uterus surgically removed because of uterine diseases, so they feel guilty and even form a masochistic personality. There is also fear of being rejected or abandoned by the opposite sex, which leads to loneliness and fear, and then forms sexual metamorphosis. I hope to express my acceptance of the other party's love by accepting the abuse and harm of the opposite sex.

Second, out of resistance to authority and self-defense against setbacks. Some people have been bullied by others in their personal life experiences, especially the rejection and insult of the opposite sex, thus forming a strong revenge and resistance psychology, showing their strength and desire to conquer by abusing the opposite sex, and getting pleasure from it.

The third is out of compensation for excessive inferiority. A.Adler, an Austrian psychologist, once pointed out that people compensate their sense of inferiority by pursuing superiority. Some people feel uneasy about their personal ability, physical quality, social status and other defects, and feel inferior, so they vent their repressed sexual instinct and psychological tension by hurting the opposite sex. In the process of controlling and hurting the opposite sex, their sense of superiority seems to be revealed and proved.