A self-mutilated or abused person is self-mutilated or abused because he is forced by too strong instinctive needs, and he longs for direct satisfaction, while complex reason lacks normal means to meet these needs. Therefore, in order to achieve the temporary balance between individual physiology and psychology, complex rationality has to return to the inside, turn to the rational model, and vent in an unusual disguised form of self-harm or abuse. This is the mechanism of self-harm or self-abuse.
Because in the behavior of self-harm or self-abuse, the subconscious desire and its derivatives can't be carried out in the normal state, and they can only make breakthroughs in the distorted way of self-harm or self-abuse, and seek limited satisfaction in unnatural behaviors that do not meet the requirements of social morality and habits. It can be seen that self-harm or self-abuse has seriously disturbed or even distorted the function and function of consciousness to some extent, which is a mechanism to adapt to abnormalities in one's psychological development.