In Islam they also have polygamy, but it's restricted to 4 wives and the husband is supposed to treat them all equally. Of course, when they go to heaven the men have the fabled 72 virgins as well as their wives... and apparently also pretty youths. Not sure what the Mormon afterlife is like, I read that each man gets his own planet? And apparently women who are unmarried or child-less don't get to go to heaven?