My childhood best friend's family would tell their young daughter, maybe 5-7 years old things like "Im gonna call the bad man" or "The bad man's gonna get ya if you dont be good." I dont think they did this a whole lot but even if it was a rare thing for her parents, her older brother definitely took advantage of her fear on this "bad man" thing.
It definitely made her straighten up, but Im wondering if this discipline strategy, "fear of a thing" can have negative side effects.
Now that I'm writing this question, I guess Christians do this with the Devil / "You'll go to Hell if you dont live right", and children are probably more scared by this teaching than adults, if my childhood memory serves me correctly. So if the "bad man" fear disciplinary strategy is a bad thing for kids, might the religious version also have negative effects on them?