I don't think SA is due to an specific cause but a complex group of experiences a child has been experiencing as a response to on part, his own temperament and how this temperament interacted with what he received from the outside.
God!It's all predicted and dictated from the outside, we have to follow models that maybe don't fix with ourselves at all. So if there exists a contradiction between our inner and these models, we feel inadequate.
I think some people for a reason can wear a social mask but some other as us, we can't and feel guilty because we have the feeling that we failed.