In many regions, the central cultural idea is that of a lineage, a family and its line of male ancestors and descendants. The prime duty in these cultures is to keep the lineage going. Religion is small scale with the ancestors performing many of the functions of gods. Denser populations and larger political entities lead to large-scale religion where conformity is stressed and cultural rules are codified in a book and not subject to discussion with the ancestors. In pre-modern Sub-Saharan Africa, land was not limiting, so a maximum number of children was desired. Neither monogamy nor chastity were valued as much as fertility. Families were not nuclear; husbands and wives did not engage in many activities together; children were often raised by other members of the village and women had the responsibility for economic support of the children. In many areas of Sub-Saharan Africa, farming is the work of women. Women often prefer men with resources which leads to polygamy. Women in polygamous relationships form support groups for each other and men enjoy the fruits of several women's labor and children. In temperate regions, the land eventually fills up and the dangers of overpopulation come to the fore. Peasants are miserably poor. Massive epidemics (the Black Death, 1347 and onward) and wars (the Catholic-Protestant wars, 1562-1648) can kill a third of the population.