Monday, May 12, 2014

Human Biodiversity (2): The Genetic Evolution of Capitalism and the Bourgeois Virtues?

In a paper that summarizes his book A Farewell to Alms (2007), Gregory Clark states as his thesis that there has been a Darwinian history of recent genetic evolution that explains the triumph of capitalism and the bourgeois virtues:
"Before 1800 all societies, including England, were Malthusian.
The average man or woman had 2 surviving children. Such
societies were also Darwinian. Some reproductively successful
groups produced more than 2 surviving children, increasing their
share of the population, while other groups produced less, so that
their share declined. But unusually in England, this selection for
men was based on economic success from at least 1250, not
success in violence as in some other pre-industrial societies. The
richest male testators left twice as many children as the poorest.
Consequently the modern population of the English is largely
descended from the economic upper classes of the middle ages.
At the same time, from 1150 to 1800 in England there are clear
signs of changes in average economic preferences towards more
“capitalist” attitudes. The highly capitalistic nature of English
society by 1800 – individualism, low time preference rates, long
work hours, high levels of human capital – may thus stem from
the nature of the Darwinian struggle in a very stable agrarian
society in the long run up to the Industrial Revolution. The
triumph of capitalism in the modern world thus may lie as much
in our genes as in ideology or rationality" (1).
Clark presents historical evidence for the emergence of four behavioral patterns in the English that eventually brought on the Industrial Revolution:  declining violence (as measured by homicide rates), high literacy, self-control reflected in delayed gratification and increasing saving (as measured by low interest rates), and a propensity to work long hours.  These middle-class or bourgeois values increased the productive efficiency of the British economy.  Then, with the sudden spurt in the growth of the English population between 1770 and 1860, the Industrial Revolution occurred in England before spreading to other parts of the world.  Previously, such spurts in population growth had led to collapse as population outran resources--the Malthusian trap.  But now for the first time in history, a nation had escaped the Malthusian trap, because its bourgeois virtues in a free market economy provided the innovation and productivity necessary for unprecedented economic growth.

Most economists and economic historians explain the British Industrial Revolution as a product of institutional changes--parliamentary government, the rule of law, property rights, and free markets--that created incentives for innovation and productivity.  Clark recognizes the importance of these institutional factors, but he argues that there also had to be a change in the innate social behavior of the English that would incline them to respond to those institutional circumstances in such a way as to produce the Industrial Revolution.  And that required a genetic change in human nature.

According to Clark, this genetic change came through a process of "survival of the richest."  Beginning in the Middle Ages, the rich had more surviving children than the poor, and thus those with the genetic propensities for money-making and commercial life could pass their genes onto the next generation.  In this way, a bourgeois culture spread through English society through Darwinian evolution.

In A Troublesome Inheritance, Nicholas Wade has adopted Clark's theory as a crucial part of the argument for recent biological evolution as explaining human history.  In this case, the modern triumph of Western bourgeois culture and capitalist economics is explained as the culmination of a biological evolution favoring the social behavior and cognitive capacities necessary for peaceful cooperation and exchange in a modern liberal state. 

For Wade, this evolution began 5,000 to 10,000 years ago, with the transition from hunting-gathering bands and tribes to settled villages and finally large centralized states based on agricultural production.  For thousands of years, people in centralized states with Hobbesian Leviathan governments were forced to reduce their tribal tendencies to violence, and this favored evolutionary adaptations to the circumstances of agrarian states.  The next great evolutionary transition was the move into the open society of modern capitalist societies--starting in England--which made possible the explosion of population and prosperity over the past two centuries.

This seems implausible because we generally assume that genetic evolution--as opposed to cultural evolution--is so gradual that it cannot occur in only a few centuries.  Wade's response to this is to cite the famous research of Dmitriy Belyaev in showing how the selective breeding of foxes can make them as tame as dogs in only 40 years (160-61).  This suggests that a great evolutionary change in social behavior can occur in a human population if the social circumstances create a selective pressure for tameness or less violent and more cooperative behavior. 

Here Wade is adopting the argument of Gregory Cochran and Henry Harpending--in The 10,000 Year Explosion: How Civilization Accelerated Human Evolution (Basic Books, 2009)--who point to the breeding of domesticated animals and plants to show how fast evolution can occur.  One might object that the human domestication of animals and plants is artificial selection rather than natural selection.  But their response is to point out that the process of evolutionary change is the same for both artificial and natural selection--some naturally occurring variations are favored by the environment and gradually increase in frequency over time.  Indeed, Darwin himself began The Origin of Species by comparing the domestication of plants and animals to natural selection in explaining his theory.

Cochran and Harpending argue that when foragers became farmers, they came under the rule of elites in bureaucratic states who acted as breeders.  "Since the elites were in a very real sense raising peasants, just as peasants raised cows, there must have been a tendency for them to cull individuals who were more aggressive than average, which over time would have changed the frequencies of those alleles that induced aggressiveness" (111-12).  This would have selected for "bourgeois virtues"--"the traits that make a man successful rather than interesting"--such as the ability to defer gratification over long periods of time and to refrain from violence.  If Clark is right about the genetic evolution of capitalism in England, this was the culmination of a process that began 10,000 years ago.

This suggests that the evidence of evolutionary trends towards declining violence that Steven Pinker has surveyed could be evidence not just of cultural evolution but also biological evolution.  Remarkably, however, Pinker refuses to accept this conclusion because it contradicts the "standard assumption in evolutionary psychology" that human nature has not changed over the past 10,000 years and that this is supported by the "psychic unity of humankind" (612-13).  This is the fundamental assumption of Leda Cosmides and John Tooby, the founders of evolutionary psychology. 

Pinker admits that this assumption is questionable.  "Nothing rules out the possibility that human populations have undergone some degree of biological evolution in recent millennia or even centuries, long after races, ethnic groups, and nations diverge" (613).  But to allow for recent biological evolution would be "politically uncomfortable," because "it could have the incendiary implication that aboriginal and immigrant populations are less biologically adapted to the demands of modern life than populations that have lived in literate states for millennia" (614).

Pinker has a long section in Better Angels on "recent biological evolution" (611-22).  He sees six historical trends towards declining violence--the pacification process, the civilizing process, the humanitarian revolution, the long peace, the new peace, and the rights revolutions.  The time scales for the last four--less than a century--are clearly too short for biological evolution to occur.  But he admits that the longer time scales of the pacification process and the civilizing process make it possible that there could be a biological evolution at play here.

He surveys much of the evidence for recent human evolution, and particularly evidence of biological mechanisms regulating the propensity to violence that could be subject to evolutionary selection.  He notes that new techniques for scanning the human genome to look for evidence of genes that have been targets of recent natural selection suggest that approximately 8% of the human genome has been influenced by positive selection (613-14).  Here he cites a 2009 paper by Joshua Akey.  Wade incorrectly reports that the number from this paper was 14% (2, 108).

Pinker also surveys the evidence from behavioral genetics indicating that the propensity to violence is highly heritable.  And he points to many specific pathways by which natural selection could adjust human genetic propensities away from violence: self-domestication and pedomorphy, brain structure, oxytocin, testosterone, and neurotransmitters (616-18).

From all of this Pinker concludes: "Genetic tendencies toward or away from violence, then, could have been selected during the historical transitions we have examined" (618).  But, then, amazingly, he reverses direction and declares that there is no hard evidence for recent human evolution.  He quickly dismisses Cochran and Harpending's arguments: "none of the selected genes they describe has been implicated in behavior; all are restricted to digestion, disease resistance, and skin pigmentation" (619).  He summarizes Clark's Farewell to Alms in two paragraphs, and then dismisses it in one paragraph:
"A Farewell to Alms is filled with illuminating statistics and gripping narratives about the historical precursors to the Industrial Revolution.  But the Genetically Capitalist theory has not competed well in the struggle for survival among theories of economic growth.  One problem is that until recently, the rich have outreproduced the poor in pretty much every society, not just the one that later blasted off in an industrial revolution.  Another is that while aristocrats and royals may have had no more legitimate heirs than the bourgeoisie, they more than made up for it in bastards, which could have contributed a disproportionate share of their genes to the next generation.  A third is that when institutions change, a nation can vault to spectacular rates of economic growth in the absence of a recent history of selection for middle-class values, such as postwar Japan and post-communist China.  And most important, Clark cites no data showing that the English are innately more self-controlled or less violent than the citizenries of countries that did not host an industrial revolution" (621).
Wade does not think that the four problems brought up here by Pinker are decisive in refuting Clark.  That the rich have generally had higher reproductive success than the poor in most societies is true, but that's exactly what Clark's argument requires:  A history of survival of the richest is the precondition for the Industrial Revolution to spread, and England was the first to start this only because of the sudden increase in the English population.  The examples of China and Japan don't work against Clark's argument, Wade claims, because both countries have been agrarian economies like England, and they were ready to make the transition to modern economies as soon as the institutional restrictions were removed.

Pinker's last problem for Clark's argument is that Clark has not proven that the English are genetically different from other populations that have not yet had an industrial revolution.  Wade says this is an unfair criticism, because "the genes underlying violence are for the most part unknown."  He explains:
"The ultimate proof of Clark's thesis would be the discovery of the new alleles that have mediated the social behavior required for Europeans and East Asians to make the transition to modern economies.  But there are probably many such genes, each with a small and barely detectable effect, so it may take decades before any come to light" (172).
 But notice that Wade is here pointing to a major weakness in Clark's argument and in Wade's argument:  there is no "ultimate proof" for what they are arguing, because there isn't enough knowledge of how exactly genes govern the brain and social behavior to identify the precise genetic pathways for recent human evolution that are merely assumed to exist by Wade and Clark. 

Wade admits that "because the genes underlying social behavior are for the most part unknown, the parallel and independent evolution of such genes in the various races cannot be demonstrated" (85).  Throughout Wade's book, he concedes that he cannot prove his case because genetic knowledge is too limited (see, for example, pages 4, 15, 40-41, 51-54, 56-57, 58, 61, 64, 105-106, 127, 172, 185, 190, 208, 237-38, 243-44).  Consequently, much of his reasoning--particularly in the second half of the book--depends on highly speculative guesses as to what is happening at the genetic level to support his conclusions.  The best that he can do is to try to persuade us that his speculations are plausible enough that they will be confirmed sometime in the future by advances in genetic science.

Some parts of his argument are more plausible than others.  For example, his explanation for the evolution of high intelligence among the Ashkenazi Jews seems very plausible to me, despite the fact that he cannot identify the specific genetic pathways involved in this.

Adopting the work of Cochran and Harpending, Wade argues that Ashkenazi Jews have adapted genetically for occupations that require high cognitive capacity.  In fact, the Ashkenazim are a genetically distinguishable ethnic group within the Caucasian race, as indicated by a distinctive pattern of Mendelian diseases caused by single-gene mutations (such as Tay-Sachs).  They also have the highest average IQ--110 to 115--of any group that has ever been tested.  There are good reasons to believe that there is a connection between these two facts--that the higher IQ is rooted in the genetic nature of the Ashkenazim.

This connection is supported by the history of the Ashkenazim as a group that for many centuries filled occupations like moneylending and international commerce that were cognitively demanding.  Moreover, there is evidence that the wealth earned by these occupations increased the reproductive fitness of those Ashkenazi Jews in those occupations.  One should also consider that until recently Jews were discouraged from marrying outsiders, and thus they became a reproductively isolated group.  One should also notice that many of their genetic diseases seem to be associated with regions of the genome that are connected to brain function.  Even though we are ignorant of the precise genetic pathways for the evolution of high intelligence in the Ashkenazi Jews, all of these various lines of evidence add up to a highly plausible conclusion that over a few centuries the Ashkenazi Jews were genetically selected for high intelligence.

Notice also that if this is true, the evolutionary adaptation of Jewish intelligence for the cognitive challenges of modern commercial exchange was just a stronger version of what might have been happening to other groups in England and elsewhere, who were thus becoming biologically adapted for capitalism.

Some of my other posts on these topics can be found here, here, here, and here.

1 comment:

Anonymous said...

What does this theory have to say about the fact that virtually all the most non violent societies in the world are pre modern? Many still live in tribes. Doesn't that contradict this or am I missing something?