Because most philosophies that frown on reproduction don't survive.

Friday, August 10, 2007

Nothing Succeeds Like Success

Scott Carson has an interesting post up about the societal development of affluence, which in turn links to a New York Times article, which is about a forthcoming book titled A Farewell to Alms by Gregory Wood.
Dr. Clark’s first thought was that the population might have evolved greater resistance to disease. The idea came from Jared Diamond’s book “Guns, Germs and Steel,” which argues that Europeans were able to conquer other nations in part because of their greater immunity to disease.

In support of the disease-resistance idea, cities like London were so filthy and disease ridden that a third of their populations died off every generation, and the losses were restored by immigrants from the countryside. That suggested to Dr. Clark that the surviving population of England might be the descendants of peasants.

A way to test the idea, he realized, was through analysis of ancient wills, which might reveal a connection between wealth and the number of progeny. The wills did that, , but in quite the opposite direction to what he had expected.

Generation after generation, the rich had more surviving children than the poor, his research showed. That meant there must have been constant downward social mobility as the poor failed to reproduce themselves and the progeny of the rich took over their occupations. “The modern population of the English is largely descended from the economic upper classes of the Middle Ages,” he concluded.

As the progeny of the rich pervaded all levels of society, Dr. Clark considered, the behaviors that made for wealth could have spread with them. He has documented that several aspects of what might now be called middle-class values changed significantly from the days of hunter gatherer societies to 1800. Work hours increased, literacy and numeracy rose, and the level of interpersonal violence dropped.

Another significant change in behavior, Dr. Clark argues, was an increase in people’s preference for saving over instant consumption, which he sees reflected in the steady decline in interest rates from 1200 to 1800.

“Thrift, prudence, negotiation and hard work were becoming values for communities that previously had been spendthrift, impulsive, violent and leisure loving,” Dr. Clark writes.

Around 1790, a steady upward trend in production efficiency first emerges in the English economy. It was this significant acceleration in the rate of productivity growth that at last made possible England’s escape from the Malthusian trap and the emergence of the Industrial Revolution. [from the NY Times review linked to above]
Clearly, there are potential pitfalls one gets into when applying evolutionary-style analysis to cultural questions. And yet, to the extent that these practices and attitudes are heritable (which certainly doesn't mean that they're strictly genetic, just that there's enough heritability for relative reproductive success to change the prevalence of attitudes) it stands to reason that they could be selected for.

On a side note, something that struck me in reading the NY Times articles was that Dr. Clark seemed to be somewhat surprised that the rich had more surviving children than the poor. It seems to me that one would expect to find this in any healthy society where resources are not so plentiful that people at all levels of society can have as many children as they want. This is one of the senses in which (up until the last century) humans tend to act like the creatures they are. It's generally within the last hundred years (and at certain other points in history in various societies: the beginning of the Roman Empire and certain periods in feudal Japan spring to mind) that not having children has come to be a sign of success.

This is probably related to (though as a cause or effect I do not know) the decline in dynastic thinking in modern society. Only a very small percentage of people in our current society have family estates or businesses which have existed for many generations, and require people to think in terms of bearing, raising, educating and training the next generation in order to carry things on.

Not that people don't think about "the next generation"; but it the general attitude I hear around the corridors at work (which I take to be a more standard milieu than our friends from church or among homeschoolers) seems to be that "the next generation" is simply something that happens. One may or may not produce a few members of it, but generally it's a strange and separate entity which tends to spring up, demand video games and college tuition, and then go off to do its own thing. If people think about "carrying on the family" it generally seems to be as a somewhat backward desire usually expressed by aging parents who want grandchildren to spoil before they are too old to enjoy it.


Suzanne G. said...

Interesting thoughts there. Here are two more to add to the pot.

1. Abortion: in the 1970s in the US, the Republican party was the party that supported abortion. The premise was that fewer poor meant less welfare. A controversial study from the late 90s posited that the lower crime rate during the Clinton administration was because there were 1 million fewer children born into an unwanted situation who then did not swell the ranks of criminals 15-20 years later.

2. Declining Birthrates: In all industrialized countries of the New World and Europe, birthrates are declining. The studies of the time of George Washington through Woodrow Wilson don't reflect this. Our US birthrate is below that of replenishing those who die. Were it not for immigrants from less developed countries, we would not be growing at all!

CMinor said...

A couple of thoughts that came to my mind:

--I wonder if the researcher considered that the wealthy would be far more likely to leave wills while people of, say, the serf class, who owned close to nothing, might be less inclined to bother.

--Ever since Razib of Gene Expression wrote a post on differing fertility rates some months ago, I've wondered about the wetnurse factor. Until the mid-eighteenth century when in some parts of Europe engaging a wetnurse became such a rage that tradesmen were going beyond their means to have them (kinda like some folks today with luxury cars or the latest tech gadget!)the practice was limited to orphans and the very rich. The result of a wetnursing arrangement is usually reduced fertility for the wetnurse, who may be nursing more than one baby simultaneously (though wetnurses to the rich often farmed out their own children to lactating women of less repute, to the detriment of those children)and increased fertility for the mother, whose milk dries up quickly in the absence of stimulation and whose body reads the situation as "Hey, what happened? No baby? Better start over, then!" The result of nursing one's own baby, which would have been the normal condition for most of the female population would, again, be reduced fertility. So you would end up with a population in which your average highborn lady would, God willing she didn't die in the process, be reproducing like a prize heifer while your average tradesman's wife or working-class woman would either be pregnant or have a baby or two at the breast for a good part of her reproductive life and would therefore be fertile for less of it. In fact, it wasn't unusual for those highborn ladies (think some of the European queens, for example, or someone like Mary Wortley Montague) to bear a dozen or more babies, with survival resting heavily on the quality and personal habits of her wetnurses. Other factors would also be at play--our highborn lady would be less at the mercy of winters, famine, and hard physical labor than would most women of other classes.

So while I'm not surprised to learn that the wealthy were more prolific, I think the behavioral factors involved are often overlooked. I suspect researchers who have spent much time lactating themselves are few and far between!

--I also still wonder about the urban/rural connection. I remember reading something some time ago to the effect that overall child survival in Colonial and early Federal America was lower than in Europe, probably because of the sparse population. The passage mentions the high urban death rates; perhaps different methodology in rural areas (might rural folk be less likely to register wills?)would show other results.

Anonymous said...

"That meant there must have been constant downward social mobility as the poor failed to reproduce themselves and the progeny of the rich took over their occupations."

Hogwash! As pointed out by other commenters, the poor almost never had wills, so any study based on old wills is fatally flawed from the start. Infant mortality rates were shockingly high for all classes during the Middle Ages, and the rich would have had a bit of an advantage, but considering that 80% plus of the population would be considered poor, not enough to upset the basic statistical imbalance. There is also plenty of anecdotal evidence from the Middle Ages that would seem to suggest that the average poor family had more children than the average rich family. Considering how desirable another child would be in a peasant family to work in the fields, and as a support for parents in old age, that shouldn't suprise anyone. He also underestimates the role of upward social mobility in the Middle Ages. The old English saying of three generations up from the gutter and three generations back down to the gutter was a good shorthand description of the fact that even in the Middle Ages the classes were not static.

CMinor said...

Sheesh...I did it again.
That "mid-18th Century" in my comment should have read "mid-1800's." I knew what I meant, but nobody else did. I sometimes wonder I can keep my checkbook balanced.

I think Donald above made a good point about the relative proportions of rich to poor in times past--when the poor make up a disproportionate amount of the population, meaningful comparisons to the handful of wealthy in the population are going to be difficult.

But I still think lactation infertility probably made a difference in birthrates overall.

Darwin said...

I don't think he's looking at the number of wills to determine how many rich vs. poor there were, but rather using them to compare the number of adult children for people of various economic levels. Thus, unless there are _no_ wills for people from the lower classes, you should get some data.

I haven't read the book, so I don't know of the overall quality of his arguments, but two things to keep in mind:

It sounds like he's specifically talking about the demographic dynamic in cities. So the argument would be that in cities, people with more money tended to have more children survive to adulthood. This strikes me as fairly common sensical -- so it wouldn't necessarily surprise me.

Also, keep in mind (when speaking of surfs) that (if memory serves) the even at the lowest levels the inheritance of the land that provided serfs with their livelihood tended to go to the oldest male child. So while on the one hand there was a need for more children, of the male children only the oldest was fairly certain to have enough means of support to a family. This might put the younger sons of craftsman oriented town families in a better position to go find their own livelihoods than the younger sons of argicultural serfs, thus in the long run producing greater population growth among that group.