Isaac Bonewits (the first, and the only that I know of, person to
get a degree in Magic from an accredited university) wrote a book
called Real Magic that did a fair job on some of this stuff. I'm
fairly sure it's out of print, though.
I think filtering, guided imagery, coincidence, the placebo
effect, and peer pressure account for a lot. Not being
particularly concerned with Occam's Razor or the scientific
method also helps.
Kennita