Yes, true, it could be entirely organic. Like the Texas Tower sniper Charles Whitman. If I have the history correct, he went from normal to incredibly disturbed as a tumor was growing inside his skull.
Very true.Who knows? The guy could have just been a scumbag,on drugs,severely depressed and/or psychotic (which could be chemically based) or,as I noted in Post #48,he could have been brain damaged.The human brain is,in reality,just a mass of cells...just like every other organ of the body.If your liver is damaged,either through injury or a biological process,you turn yellow.If your heart is diseased you have pain,or become weak,etc.If your brain is diseased either through injury or a biological process then,in some cases at least,you can do very bad things that aren't part of your true nature.
Nothing conclusive was ever proven about Whitman’s tumor having an effect on his behavior. Months before his rampage, he told a psychiatrist he was thinking about going up in the Tower and shooting a bunch of people - but the shrink didn’t take it seriously enough, notify law enforcement or anything.
Of course, that was a different time...