I know plenty of irrational engineers, being one myself. Some of them blame long-term exposure to architects for the condition [winking at Steve G]...

Frank is onto something by invoking the placebo effect. Rational or not, there are conditions and experiences that individual humans percieve as 'real'. Some of them manifest as uncontrollable behavior of one sort or another - many of those have crossed the line from the supernatural to the psychological (Turette's Syndrome, for instance, and pardon any misspellngs); others have not. In either case, there are palliatives, if not cures, that depend on the minds of the sufferers as much as the ills do. The ritual of exorcism is one of these.

Fox