Cargo Cults, Unbelievable but True

Cargo Cults developed mainly in New Guinea and Melanisian areas, and generally occured only after some type of interaction with outside influence, namely war. This phenomenon can be described breifly as follows: These populations, generally pre-industrial tribes, become exposed to outside and more developed nations. This usually happens with an influx of material things, and especially during war time.
They see great ships, and airplains, and all the technological advancement that war brings. These are items and ideas that they have been unexposed to, and they believe that their Gods have meant these items and material wealth for them. They grow to covet these items, and then, when the conflict ends and the influx of new materials stops, they practice magic and rituals in an attempt to restore the flow of goods. These include making crude imitation landing strips to appease the gods, radio and communication equipment are replicated, and the behavior of the military men once present is immitated. All in an attempt to regain the "prosperity" brought to them by war.
After a time of conflict ends, most of these cargo cults die out, eventually. But one is left to wonder, how did they see things this way, and why would the material realm have such an influence on the metaphysical? Studies have shown that nearly all cultures and divisions of humanity have relatively similar IQs. These were not stupid people, but they chose to believe in an idea that seems absurd to most of us today.