Warning: The “information” herein is part of ongoing theory drafted by me, and please use discretion when reading. Thanks!
I believe negative symptoms manifest itself whenever the human’s brain cannot catch up with his heart’s desire.
As the result: In this case, it would upset the brain for not able to fulfill the request demanded by the heart’s desire. At worst, the brain withdraws itself altogether anticipating the failure in fulfilling those request (to avoid further upset).
On the contrary, positive symptoms are there because the human’s brain is isolated from his heart’s reality.
As a result? The brain becomes excited as if it was independent and free from moral restraint. (Compare delusion and hallucination to dream. A dream can be moral-free.)
The schizophrenia is a biological problem where the brain is regarded as hardware and figurative heart is regarded as software.