Why have so many cultures produced amulets as forms of spiritual protection and good luck charms? I don't think that "they were ignorant of parapsychology and modern medicine etc" actually adequately explains their emergence. Is it a functon of man's innate will to control nature, and as best a shot as she and he could given the limited information available? Also, if amulets can have a placebo effect, and help positive thinking, is that (cetrus paribus / all else being equal) such a bad thing?
-- Okay, expert -- if you say so.