[Continued from Part 1]
Restraint, Relationships and Planning Parenthood
When I say that we "naturally want to avoid having children" at certain times, I would imagine that the image that comes immediately to mind is of birth control, abortion or infanticide, and most traditional societies have seen these in some form or other. However, I'd like to turn our attention to something so basic and so prevalent that we don't think about it much.
From an anthropological point of view, the entire structure of our romantic and family relationships serves as a way to control childbearing, limitting it to situations in which offspring can be supported. Consider: Requiring that young women remain virgins until marriage ensured that children will not be born without a provider. Nor was the decision to marry, when it came, a strictly individual affair. Marriage was negotiated and approved by the wider families, because the families were in effect committing to help support the new family unit being created. Many cultures also required the husband's family to pay a "bride price", not simpy as compensation for the lost contribution of the daughter to her own family, but as proof that the husband was of sufficient means to start a family.
Once in place, this set of cultural mores and laws provided an easy way to adjust to want or plenty: In good times, people married young, in bad they married late and some did not marry at all. Within a marriage, the strong cultural ideal of the faithful wife ensured that if husband and wife avoided intercourse to space children the husband would not find some other male getting his genes in on the sly, while the cultural rules surrounding legitimacy assured the wife that even if her husband was unfaithful during such a time, any children resulting would not supplant hers in terms of inheritance or prestige.
A dramatic example of the extent to which marriage age was used to manage fertility can be seen in Wrigley's Population History of England, which makes a strong case that the English population explosion in the mid eighteenth century through the early twentieth was a result of a decline of in the average age of first marriage for women from 26 to 23. (This, coming at the same time as increased life expectancy caused the population to grow dramatically, and triggered a round of Malthusian worrying by the cultural elites.)
With marriage choices as the primary means of regulating reproduction, the other key factor, in addition to marriageable age, was the number of people who never married. In Western Europe from the Middle Ages through the Industrial Revolution, 10-25% of women never married. In poorer countries such as Ireland, both late marriage and spinsterhood came into play with the result that as few as 30% of the women of childbearing age were married at any given time. (Comprehensive demographic data here. Example table of percentage of women of childbearing age married by country and decade available on page 21 of this paper.)
What we see when we view demographic history is that marriage (and chastity outside of marriage) is an adaptive trait which allows us as rational creatures to regulate our fertility. The fact that the signs of female fertility are hard to discern means that any sexual act with a woman of childbearing age may result in the creation of a child. And the set of moral and societal norms surrounding marriage provide us with a way to manage that fact responsibly in order to have children only when we believe we can support them. This evolutionary analysis actually leads to a definition of marriage which is startlingly similar to a traditional Christian understanding of marriage: In both cases one of the primary ends of marriage is to assure that children come into being only when others are prepared to love and care for them.
[to be continued: Part 3]