I mentioned before that it can be a solution to problems facing married couples. Consider a woman who can't bear children. Is the couple condemned to a childless family? Or a woman who is handicapped and can't find a spouse as the blind girl I spoke about. Or generally speaking older ladies who haven't had the good fortune of finding a husband but are ready to accept being a second wife instead of being alone for the rest of their lives. Real life puts societies in front of such problems and polygeny is a solution. For your information POLYGAMY is multiple relations by both spouses and is detested and forbidden because it loses the origin of kinship which is a basic human right, the male member being the sole reference for this origin.