I am reading "Expecting Armageddon: Essential Readings in Failed Prophecy" edited by Jon R. Stone. I am just on the introduction, but already I see there is plenty of evidence that Festinger's thesis is correct (at least in broad sweeps). When faced with an embarrassing contradiction in their beliefs, people go to extreme, sometimes very illogical measures, to reduce thier discomfort.
Here's an example from the book about another cult, BUPC:
"..unlike their enthusiastic leaders, who continuet to prophesy doom despite repeated failures to predict exact endtime catastrophes, BUPC members had become increasingly desensitized to repeated endtime predictions and preferred instead to continue expecting the end in theory while advancing their Baha'i faith in practice."
Sound familiar? It reminds me of the Witness shuffle. The slow dance of evangelism that everyone secretly knows is a complete waste of time. But the social aspects, well. The coffee breaks almost make it all worthwhile, right?