No, I have no reasoning behind it. That is simply the definition of psychopath. Psychopaths, at the base, are born, and it is a genetic neurological thing. Sociopaths= outside factors and society by definition. Many psychologists do not believe that psychopaths can be "made" although there are movies that say so... but movies are only fiction. And this means, that they do not believe sociopaths exist. From what I've read on the subject, I would agree. A psychopath is born unable to feel empathy (as well as other things of course but that's one thing everyone can say off the top of their head), they have decreased fear, et cetera. It seems pretty unlikely that someone coincidentally goes into the same state from abuse or trauma... they have literal brain differences that they are born with. There is a way to FOR SURE know that someone is a psychopathy- some type of brain testing or scanning.
Now, perhaps something like decreased empathy, being torn up inside, not caring anymore, et cetera, THAT... but that is not a psychopath. They have a complete inability to feel empathy in the first place. It's just the truth. Someone who wasn't born with psychopathy would know what empathy is, know exactly what people by right and wrong, etc. Mary Bell could be an example of someone torn up inside who appeared to be a psychopath, but later after the institution she was fine and is raising her children (Mary Bell was a child killer, meaning she killed people when she was a young child)