According to his entry in the IBM 2000 World Book, Schizophrenia is caused by immediate family. It is actually caused by the imposition of external laws on the individual without explaining to them why the laws are beneficial, which then separates them from any personal, direct, immediate relationship and understanding of truth (in this case the laws). Understanding of truth is something that arises from within, by comprehension (the aha or eureka moment). Externally imposed laws, of any kind, which have not been comprehended by the individual create tension, and effectively distance the self from the belief that they can understand the 'why' of it. This tension can manifest itself in any form from apathy to violent hostility. If these laws are in regards to the treatments of others, then their hostility or apathy (but tending towards non empathy) will be directed towards the other people to whom the law is concerned. Why to those people? Because without those people, there would be no need for the law to exist, or possibly because those people remind the person of their powerlessness, and thus the easiest way to eliminate that feeling of powerlessness is not by destroying the law, but by destroying the people with whom it is concerned.
These laws (an ethical system if you like) regarding the treatment of others may be so universally applicable to all people, that whenever the individual is confronted by another person, he is reminded of his powerlessness, and thus feels antagonistic or apathetic (generally distanced from) all peoples.