Savage Reservation

As I was rereading Brave New World, in chapter eleven, the book tells about how savage reservation is a place where it is unsuitable to convert the area to be civilized. Since the people put the savages who do not fit in a civilized society in one area, would the cultures of the savages mixed together? I wonder this because when Bernard and Lenina went to the Savage Reservation in New Mexico, they saw a practice where a person was nailed to the cross and whipped until bleeding. This practices I believe came from two religions which is Christianity and a religion that came from the early societies in Mesoamerica such as the Olmecs and the Aztecs. The person who was nailed to the cross would be the same as Jesus nailed to the cross and being whipped until bleeding was for rain to come for the growth of the crops which is the similar concept where in Ancient Mesoamerica people made blood flowing out of their body for the grow of the crops. I would like other people to respond about how if they see this happen, too or am I the only one?