It is known, certain dramatic ends inspire ghosts, at the very least ghost stories. Murder comes to mind, especially the messy variety, a generous advantage to ghosts. Some nationalities are notably ghost-ridden, the Scots come to mind, Mexicans, Tahitans, Japanese. For some reason, Norwegians do not suffer ghosts, lutefisk is a barrier of some sort. American Indians suffer ghosts with theatric aplomb, the likely precursors to Edgar Allen Poe.