Harvey Whitehouse, an anthropologist from Oxford, is leading a massive cross-university effort called “Explaining Religion” looking at the re-occurring tendencies in religious groups throughout the world. (More on the project here)
Anthropologists kept seeing that religious ritual tended to be either low frequency/ high intensity (example: painful initiation ritual) or high frequency, low intensity rituals (fingering rosary beads). The high frequency/low intensity rituals were especially good at conveying doctrine (thanks to oral repitition) The low frequency/high intensity rituals seemed better at connecting people to each other and with divine, spiritual explanations.

To test the theory, they took two groups of college students to the woods and got them to perform certain rituals — for instance, planting a stick in the ground. The scientists told the students the rituals had been discovered somewhere and were thought to improve hunting success.
One group did it during the day, and the second group performed it at night, in an isolated location, with torches — a more frightening and emotional environment.
A week later they asked the students what the ritual meant. The daytime group didn’t come up with much. Maybe the stick was supposed to attract animals. But the nighttime groups offered all sorts of theories — such as that the stick was supposed to symbolize the penis entering the vagina, a symbol of animal fertility. Introducing elements of mystery or danger made people much more likely to remember the ritual and experience a spiritual dimension or rationale.