Thursday, August 21, 2014

A burr under the PC blanket

kw: book reviews, nonfiction, genetics, sociology, behavior

To date, Nicholas Wade has written three seminal books, which I have read in reverse order. I first read his most recent, A Troublesome Inheritance: Genes, Race and Human History, which I reviewed July 30, then The Faith Instinct: How Religion Evolved and Why it Endures, reviewed August 12. Now I have in hand Before the Dawn: Recovering the Lost History of Our Ancestors, published in 2006. His books in general criticize or expose academic mischief. These three take a more nuanced approach. While Wade is openly critical of the anti-recent-evolution stance of nearly all scientists who study human history and prehistory, he primarily presents data, draws logical conclusions, and engages the reader to think it through.

The premise underlying all three books is that human evolution continues apace. Anthropologists and others have from the beginning operated under the conceit that human evolution stopped about 50,000 years ago with the worldwide spread of "behaviorally modern humans", often called Cro-Magnon, but these days usually called Archaic Humans. This in spite of the facts that a typical archaic human was more heavily built than most moderns, and that the AH's were foragers (like chimps and bonobos are today), not even having the social organization of modern hunter-gatherers, let alone using settled dwellings. If there exist any AH's today, no matter how "behaviorally modern" they may be, they are probably being kept in prisons or hospitals for the criminally insane.

We are more gracile—having more slender bones and less muscle—than AH's. It took them, both in Africa and in the wider world a few hundred of them invaded around 50,000 years ago, tens of thousands of years to become hunter-gatherers, and another 5,000-10,000 years to begin to live in at least semi-permanent settlements. Only then, perhaps by accident, did cultivation of grains and domestication of certain animals produce an agricultural economy. I had not read before that people began to live in settlements several millennia before the agricultural revolution that began about 9,500 years ago. Only in the Americas was the order apparently reversed, with the domestication of maize preceding city-building, and that some 5,000 years later than in Eurasia and Africa.

Chapter 12, "Evolution", summarizes points made earlier in the book and adds a few pieces of evidence that we continue to evolve at about the same clip as large animals in general. These items include:

  • Defenses against malaria, including sickle cell anemia and thalassemia and a few other independently evolved modifications of hemoglobin, plus metabolic chain modifications such as G6PD, all of which evolved in the last 5,000 years or so.
  • The change from light skin, as in chimps and bonobos, to dark skin presumably came about when humans lost most hair hundreds of thousands of years ago. After a small group left Africa, most entered more northerly climes, and had less need for sun protection, plus in the most northerly, the need to make more vitamin D from what sun there was. This led to lighter skins. The situation is complicated by the last cold phases of the ice age between 20,000 and 12,000 years ago, when pale-skinned northerners would have been forced southward, only to return northward about the start of the Holocene, variously put somewhere around 10,000-11,500 years ago. The genes that favor pale skin in Eurasians are different from those in the Chinese and other East Asians.
  • Genes that affect brain size, one protective from microcephaly and another that affects the style of neural connections, arose 37,000 and 6,000 years ago, respectively.
  • Adult lactose tolerance arose about 5,000 years ago, in at least three different ways in different places.
  • Very few AH's got impacted wisdom teeth. Compare the situation today! The average modern male Euro-American lower jaw is a centimeter shorter than the average male AH lower jaw.

Such conclusions have led to criticism from academia. Curiously, having dipped into the literature some eight years after the fact, I find nearly no countering factual arguments, and mostly ad hominem attacks and circular reasoning. But things like malaria or light skin or wisdom teeth are one thing. The way we think and behave is sacred ground! Wade storms in where angels might fear to tread. But he is no fool.

It is becoming ever more clear that the human brain is no tabula rasa, on which culture can be written freely regardless of one's ancestry. Noam Chomsky and others have shown that infants have a "grammar engine" that enables them to learn language very easily. This definitely evolved well prior to 50,000 years ago, and improved communication may have been the salient factor that allowed a small band to invade eastward against probably opposition by Neanderthals and Homo Erectus. Other newly found innate skills are reported frequently. Wade contends that the modern ability to trust strangers rather than kill them on sight (or slink away to prepare an ambush) required genetic changes to our brains. Trusting was totally outside the scope of AH's. Trade is not seen between bands of apes, and is not yet universal among modern hunter gatherer tribes.

The mental adaptations needed to survive or thrive in settlements that have social order rather than total egalitarian organization are at least partly genetic. The puzzle to me is, wherever such mutations first arose, how did they spread throughout the human species? Wade mentions parallel, convergent evolution, but I am not so sure.

Bands of foragers and later, hunter gatherers, were and are so warlike that 30% of males die by the spear. That may work out to a yearly death rate due to fighting in the 1% range, but consider if the city of Philadelphia had a 1% murder rate: 15,000 per year (of half that if only males frequently kill). Compare that to around 200 yearly over the past decade. But a less murderous people are unlikely to spread into the territory of their violent cousins. This puzzle remains, but the modern fact of very low (comparative) violence.

The human species not only domesticated wolves, goats and other critters, they domesticated themselves. I am reminded of a scene from Demolition Man (1993), in which Wesley Snipes commits a bit of mayhem, and a dazed police officer says, "We're policemen. We aren't used to this level of violence". The actors other than Stallone and Snipes were chosen to be slender and inoffensive, as if they'd evolved further along the track of gracilization that has been going on for 50,000 years.

In a telling statement, Wade writes
There is no reason to suppose that human nature ceased to evolve at some finishing post in the distant past or to assume, as do some evolutionary psychologists, that people are struggling to function in modern societies with Stone Age minds. Genomes adapt to current circumstances or perish; the human genome is unlikely to be an exception. (p. 278)
I find a curious dichotomy in the past decade's debate over our failed nation-building efforts in Iraq and Afghanistan. Most pundits predicted failure, stating that the region's peoples didn't think in terms favorable to American-style capitalism and representative democracy. "They are tribal peoples, it doesn't make sense to them." They were right. Some commentators even implied that peoples such as the Afghans can't think in these terms. Though this further implies that their brains work differently, they'd be aghast if this were pointed out. But if our genetics reflects our heritage, including adaptations to all of the past environment including culture, then it follows that the kinds of thoughts we are able to think is affected, if not delimited, by our ancestry.

Had Wade written only Before the Dawn he'd have been in sufficient hot water with academia. But he took Chapter 9, "Race", and part of Chapter 8, "Sociality", particularly the section on Evolution of Religion, and expanded them into the two later books. Now he is being attacked not only by evolutionary psychologists and anthropologists, but also the Civil Rights establishment—and the PC world in general—and many Christians (Jews, Moslems and most others mainly greeted The Faith Instinct with a yawn).

Face it, folks. There is no dichotomy between "man" and "nature". We are part of nature. We continue to evolve, both in body and in mind. Isn't it now a tenet of psychology that we are not body plus mind, but a body-mind, that the mind is a product of the body? The brain is part of the body, and evolves also. It must have required a significant change in how human brains work in order to allow people to settle down in communities larger than about 150, and a further, equally significant change to yield a 100-fold reduction in lethal violence over the past 20,000 years or so. Even the infamous Yanomamo of Brazil, murderous as they are, have a lower violent death rate than the typical group of AH's. Isn't that a good thing?

Is there a family anywhere that is composed of adoptees from radically different cultural heritages, but all were adopted as infants? This would constitute a small, natural experiment. To what extent would the infants, once grown to adolescence and adulthood, become comfortable in their adopted culture? I mean totally comfortable. Were such a family in suburban Minnesota, for example, would they all become productive taxpayers and voters? Would things such as the rule of law ("…a nation of laws and not of men.") make for them the kind of visceral sense it does to Euro-Americans? Maybe and maybe not. If Wade's thesis is correct, there would be a differing response to Western institutions depending on genetic heritage.

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