Tuesday, August 14, 2007

Some thoughts on evolution, history and capitalist genes...

I've been pondering the profile of historian Gregory Clark that appeared in the New York Times recently (via Cliopatria). To be honest, I find a lot of things bothersome not only about the article but also about Clark's argument itself. There seem to be a lot of people who find this work 'important' and somehow pathbreaking, but I have my doubts. And it doesn't seem that such doubts are being sufficiently raised.

The Times article, for instance, is an odd one. Some things are presented as new that don't seem all that revolutionary (as has been pointed out by Jason Kuznicki). Other arguments which are in some way new are not questioned as closely as they should be.

In particular, I refer to the 'Darwinian' claims made by Clark.

And let's be clear, these are the claims that have resulted in this book's being written up in the Times. (Garnering, therefore, attention that more mainstream cliometricians might sacrifice a limb for.)

It is curious, though, that in an article that spends so much time speculating about the genetic basis of social change there appears no commentary from people who might have something relevant to say about the matter: i.e., evolutionary psychologists or geneticists. (This is not, of course, Clark's fault.)

There have been, after all, at least 30 years or so of intensive scholarship trying to work out the extent to which biological factors influence social behaviour. Instead, the article relies on the comments of economists who, to be honest, seem a bit out of their depth when it comes to thinking about genes.

Now, I happen to find a lot of research and theory regarding what we might call the biological basis of behaviour to be very useful; indeed, I have recently argued at length that historians should take account of the increasing amount of insight into the human mind that cognitive and evolutionary psychology have provided.

So, unlike some, perhaps, I do not have trouble with Clark's argument because it's biological; instead, I doubt whether what biology his argument contains is understood and applied correctly.

And it is important to get it right, since I think it's high time that the humanities began breaking down the needless wall that has been built up between them and the natural sciences, and I think there's much to be gained by abandoning the more extreme versions of cultural theory and taking seriously again the concept of human nature.

However, in wrestling with these concepts myself (as evidenced in my recent article at Cultural and Social History on the 'limits of culture' as well as in an essay in the recently published Cultures of Violence) I think such cross-disciplinary borrowing should be done carefully.

And I'm not sure from the initial indications whether Clark is nearly as careful as he should be.

Neither is The New York Times. It is not, for instance, only 'many historians' who

have assumed that evolutionary change is too gradual to have affected human populations in the historical period.

Consider the field of evolutionary psychology, which--in alliance with a number of neuroscientists and cognitive psychologists--has given a great deal of thought to the issue of how biology might affect behaviour. (An excellent and readable introduction is available in a 'Primer' written by John Tooby and Leda Cosmides.)

One of its fundamental principles, for example, is that structure of the human psyche was fundamentally formed during the period in which our species lived as hunter gatherers, i.e., for about 99% of its existence. This doesn't mean that our behaviour or abilities are limited to the tasks undertaken in that period: we can do all sorts of things that were not 'selected for' by natural selection but which are fairly fundamental to modern life, such as reading, using a computer, or driving a car. (Many skills, though, are not fundamentally that different, as much of human life revolves around social skills and interactions that haven't changed all that much: i.e., evolutionary psychology is far less about hunting mammoths than about getting along in groups).

However, we required no additional genetic adaptations to do such things.

And, as far as evolutionary psychologists are concerned, post-stone age genetic change has been, at best, a negligible factor. As Tooby and Cosmides note:

Our species lived as hunter-gatherers 1000 times longer than as anything else. The world that seems so familiar to you and me, a world with roads, schools, grocery stores, factories, farms, and nation-states, has lasted for only an eyeblink of time when compared to our entire evolutionary history. The computer age is only a little older than the typical college student, and the industrial revolution is a mere 200 years old. Agriculture first appeared on earth only 10,000 years ago, and it wasn't until about 5,000 years ago that as many as half of the human population engaged in farming rather than hunting and gathering. Natural selection is a slow process, and there just haven't been enough generations for it to design circuits that are well-adapted to our post-industrial life. ('Primer')

It is not, of course, that those associated with 'evolutionary psychology' have a monopoly on arguments about biology.

Some researchers, particularly those asserting some form of 'gene-culture coevolution', have, in fact, emphasised the possibility of more 'recent' genetic change, cited examples typically being the development of lactose tolerance among some populations or the mutations in the sickle cell gene in populations in malarial regions.

One of the key figures associated with 'gene-culture coevolution' and 'sociobiology' is E. O. Wilson, who has done a lot more thinking about the connections between society and biology than most. Like most sociobiologists, Wilson has (wrongly) been depicted as imposing a 'determinist' and 'reductionist' model on human behaviour. (Although I don't agree with Wilson on everything, I highly recommend his book Consilience to anyone interested in the relationship between the humanities and sciences.)

I am open to the possibility that there might have been some genetic change over the preceding thousands of years (evolution, after all, has not ended).

It is also true, I think, that in some sense we only have as much culture as our nature allows.

But even Wilson, the arch-sociobiologist, who argues that culture might promote genetic change in the long term, concludes the following:

'While individuals within a particular society vary greatly in behavioral genes, the differences mostly wash out statistically between socieites. The culture of the Kalahari hunter-gatherers is very distinct from that of Parisians, but the differences between them are primarily a result of divergence in history and environment, and are not genetic in origin.' (Consilience, 155)
One reason for that last statement is that behaviour and thought result from complex assemblages of mental elements, and Wilson is clear about the level of generality on which the 'epigenetic rules' that shape our preferences operate:

'Genes do not specify elaborate conventions such as totemism, elder councils, and religious ceremonies. To the best of my knowledge, no serious scientist or humanities scholar has ever suggested such a thing. Instead, complexes of gene-based epigenetic rules predispose people in invent and adopt such conventions.' (Consilience, 181)

I would extend Wilson's reference to 'elaborate conventions' to Clark's 'middle-class values', and would, therefore, question just how 'serious' this claim is.

For instance, Clark's claims about adaptation (for his argument is basically an adaptationist one) seem to be somewhat confused. From the NYT article, we learn,

“Through the long agrarian passage leading up to the Industrial Revolution, man was becoming biologically more adapted to the modern economic world,” he writes.

It seems to me that the 'long agrarian passage' and the 'modern economic world' contain enough serious differences to make the alleged genetic adaptations to the former not entirely a preparation for the latter.

Keeping in mind Wilson's caution noted above, however, the adaptations in question seem to be the following:

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

Now, leaving aside Clark's rather simplistic view of pre-modern social history (which would require another equally long post, so I'll spare you), he is presented in the NYT article as being undecided on the issue of whether these 'values' were being transmitted via culture or genes. There is something rather too offhand about his references to genes.

However, in his essay 'Genetically Capitalist? The Malthusian Era and the Formation of Modern Preferences' (available here, thanks to Steve for bringing it to my attention) there is somewhat less ambiguity (Subsequent references to 'GC').

The abstract will give you a solid sense of the argument, one part of which is:

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. (GC, 1)

The recurring 'may' (just like the question mark in his title) leaves some wiggle room, but the genetic gist is clear enough in the body of the article: Clark's aim, I think, really is to argue that in some kind of very specific way, capitalism really is in our genes.

In making that argument, Clark makes a number of assumptions. This, of course, is fine, all historians do that. However, he seeks to support enormously weighty conclusions on rather shaky foundations.

For instance, a major part of Clark's argument seems to be that there was a general technological, social and cultural stagnation before 1800. (Sometimes it's technological, sometimes it's social; however, he jumps around rather rapidly between different kinds of measurements and standards.) He states that we can test empirically the question of

whether the average person in 1800 was any better off than the people of 10,000 BC on any dimension, and the answer is no. (GC, 10, emphasis added)

This extraordinary claim (life was not better 'on any dimension'?!) is based upon a comparison of calorie intake. But his data for England are based upon extrapolations from data about the poorest among the English and his comparison with the hunter gatherers comes from modern hunter-gatherers. These latter societies are, by definition, most likely the most successful hunter gatherers (since they are still around), but Clark uses them as a basis to make quite extravagantly general claims about hunter-gatherer life:

Primitive man ate well compared to one of the richest societies in the world in 1800. (GC, 15)

I think there is something to the argument--made convincingly by Jared Diamond in The Third Chimpanzee--against the naively 'progressivist' view of agriculture (i.e., that it made everyone's lives better). But Diamond (who has a lot of experience with hunter-gatherers and has written extensively about the deep history of agriculture) considers that 'all those modern hunter societies have been affected by farming societies for thousands of years and do not tell us about the conditions of hunters before the agricultural revolution' (Third Chimpanzee, 167).

(I think they do tell us something about those conditions and they are a useful means of reaching broadly accurate conclusions about about life in the Pleistocene, but I think one has to be far more careful about reaching the far more specific conclusions that Clark does .)

([UPDATE]: Peter Ryley has posted a nice discussion of 'deep materialism' and Diamond's Guns, Germs and Steel. I too think it is an intriguing book.)

Now, I'm a humble cultural historian, and not as statistically competent as the cliometricians in my profession, but when someone takes a rather selective range of calorie intake figures from broadly diverse societies ('1,452 kilocalories per person per day for the Yanomamo, to a kingly 3,827 kilocalories per day for the Ache', GC, 15), uses them to create a median and lets this stand for the life of 'primitive man' I think it's fair to be more than a little sceptical. What if most hunter-gather societies were more like the Yanomamo than the Ache? Wouldn't this have a significant affect on the resulting median?

I don't know. But I suspect there is a lot more complexity (and uncertainty and margin of error) behind these figures than Clark suggests.

Clark's other key notion, according to the Times, seems to be that “The modern population of the English is largely descended from the economic upper classes of the Middle Ages”.

Now, again, I'm not an economic historian or a demographer. But a few things occur to me immediately.

First, real 'upper classes' tended to be vanishingly small in terms of their population. (The following info comes from The Peoples of the British Isles: A New History 1688-1870 by T.W. Heyck).

In eighteenth-century Britain, the titled aristocracy (with, say incomes around 8,000 pounds a year or even far more) made up less than two hundred families; adding in the big landlords of the gentry (with 1,000 pounds or more) brings us to somewhat more than 15,000 families, or less than 1.5 percent of the population, who possessed about 15 percent of the national income.

On the other hand, we have people who actually did most of the work in the country, from freeholders and tenant farmers to farm labourers. There were about 350,000 families who could be ranked among the freeholders and farmers, most of whom earned between 40 and 150 pounds a year. There were a further 400,000 families of 'cottagers' or 'paupers' earning around 6 or 7 pounds a year. There were also large numbers of labouring poor in the towns (and the towns, recall, only made up 20 to 25 percent of the total population) and an indeterminate population of beggars and vagrants.

There were also many in the 'middling ranks' but determining what that meant was difficult. As Paul Langford (in A Polite and Commercial People) has noted, 'the most elementary generalizations about it are difficult to sustain' and, based on rather fuzzy contemporary statistics, he suggests that anywhere between 20 and 40% might be considered in the 'middling ranks'. (61-63).

These admittedly come from a somewhat later period than the sixteenth and seventeenth century sample noted by Clark, but since he argues there were 'static living standards' before 1800, this shouldn't make much difference.

Clark is of course right to note some degree of 'downward mobility' for wealthier classes, and the historical problem of what to do with 'younger sons' (due to primogeniture) has long been of interest to English historians.

The big winners in England were the first-born sons, who generally inherited the estate as a whole. Many of those who did not inherit went into the expanding professions and became merchants: but Clark's claim seems to be that they also served to replace the working-classes, particularly in urban areas. As the Times article argues:

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.
Now, Clark does seem to demonstrate--at least in the sample he's examining, which, considering the level of generality of his argument seems a bit small--that there was some downward mobility in the seventeenth century (GC, 34).

But there seems to be a logical problem with his argument connecting wealth to reproduction to capitalist genes.

Looking at the data from Clark's paper, while there may have been some downward mobility, it looks very incremental, as people moved from 'the rich' to the somewhat less rich.

However, the idea that the children of the aristocracy were turning into agricultural labourers is far fetched.

There was, of course, likely to be rather more mixing at lower levels, where the borders between the lower middle 'ranks' and the upper levels of the labouring classes could be somewhat porous.

But, in the absence of more significant mixing from the top to the bottom, Clark's argument seems a bit shaky.

Why? For the moment, let us grant (which I doubt we really can) some kind of genes which directly generate the middle-class values that Clark suggests they might. Even in this case, if the 'rich' were not sinking immediately down into the ranks of the poor (taking their money-making genes with them) then how, we might ask, did those rich genes make it to the lower classes?

If it was step-by-step, through the gradual process of downward mobility, then it seems we have a problem (or rather Clark does): those who are moving downward across the generations are unlikely to be in possession of the magic success genes. If they were, they wouldn't be ending up poorer and poorer every generation.

Alternatively, if the genetic mixing was between social levels that were much closer anyway (and this is likely the way it was happening), I'm not sure that one can make the argument (even based on Clark's questionable notion of a tight gene-success relationship) that this would have meant much, genetically speaking, since the people at each level would have been more genetically similar. (Again, taking as an assumption that the gene-success relationship is valid.)

Neither option bodes well for Clark's argument.

This is entirely overlooking the fact that the question of who remained at the very top of society, the aristocracy, was not decided by which child was necessarily the most 'successful' (or even by the question of competence), but rather by simple birth order and sex. The first-born son got it all. And, even if he were a relative moron, it was likely that in some way he would remain rich and an attractive marriage partner for some aspiring merchant's daughter.

Now, we also have to keep in mind that this whole issue of upward and downward mobility is taking place in a period of time that is at least 600 years or so long (Clark focuses on the period between 1250 and 1800.) Clark seems to see this period as one large Malthusian mass of 'static living standards' (GC, 37). And he may be right that there is a recognisable amount of continuity--certainly according to the numbers and factors he chooses to pay attention to.

However, this is also a period in which there were major social, political and cultural changes. This period, after all, includes the Black Death (which had a major impact on relationships between labourers and landowners), frequent struggles between monarchs and nobility, the development of trade, increasing exploration, several wars and changes in agriculture such as the increasing incorporation of farming into a market system and the furtherance of enclosures.

All of these factors affected the composition of the social elite, though for different reasons. One might be granted a peerage, for instance, for reasons that had little to do with capitalist success and rather more to do with simply being on the right side of a political squabble, making a good marriage or having success in war. (Just as losing one's wealth might have had to do with contingencies related to the above factors.)

'Wealth' and 'success' were being amassed in England in a variety of ways: slave trading, tobacco planting, empire building, monarch-bribing, textile weaving and goods trading (not to mention, at least in the earlier period, being good with a sword).

Which gene is it, precisely, that is going to promote success in all these different ways of getting ahead in life?

Evolutionary biology seems relatively clear on the point that adaptation requires strong environmental pressures leading in one direction. However, is it not likely that the turbulent period between the late middle ages and the beginning of the modern era and the variety of economic and social activities that led to success during it somewhat undermines the notion that genetic influences would have consistently been selected for leading to Clark's rather idealised version of the middle-class man?

After all, combined with the unlikelihood that 'downward social mobility' was sufficient to transmit rich peoples' genes from the tiny successful class at the top to the broad social base, at the bottom, just what were those who became rich as merchants trying to do with their hard-earned and saved money? That's right: become aristocrats. And being one of those involved a set of behaviours (enormous and wasteful conspicuous consumption among others) that was rather different than the ones Clark emphasises.

It involved a great expenditure to maintain that lifestyle to which so many wished to become accustomed.

Clark's wish to find some kind of consistent, steady genetic selection for particular traits that are particularly well-fitted to capitalism seems questionable on many grounds. It must also be noted, I think, that the bibliography of his 'Genetically Capitalist?' essay--while it contains a lot of interesting history, economics and anthropology--includes precious few references from the natural sciences that would back up his rather extravagant (yet somehow strangely off-hand) reliance on genetics.

The fact that societies around the world are making rapid changes to more market-based, free-enterprise systems in a generation or two (and the ability of second-generation immigrants from some of the poorest countries in the world to thrive in some of the richest) should make the obvious point that one doesn't need genetic difference to have social change and variety.

I prefer not to make too harsh a judgement of a book I haven't read, but based on the information in the Times article and Clark's essay, I think those who do read it should do so with a number of questions in mind.

In the preface to his new book (via here), Clark writes:

Doubtless some of the arguments developed here will prove oversimplified, or merely false. They are certainly controversial, even among my colleagues in economic history. But far better such error than the usual dreary academic sins, which now seem to define so much writing in the humanities, of willful obfuscation and jargon-laden vacuity. As Darwin himself noted, "false views, if supported by some evidence, do little harm, for every one takes a salutary pleasure in proving their falseness: and when this is done, one path towards error is closed and the road to truth is often at the same time opened."' Thus my hope is that, even if the book is wrong in parts, it will be clearly and productively wrong, leading us toward the light. ...
I would concur with Clark on the 'dreary academic sins', and I would much rather interact with a a clear argument that is wrong than a muddled one that doesn't even contain enough content to be wrong.

I'm not sure, though, whether his argument is leading us toward light or toward a dead end. And it would be unfortunate if historians took Clark's questionable arguments as a definitive statement on what Darwinian perspectives on history and society potentially have to offer. Getting it too far wrong may not end up leading us forward but rather setting us back.

[Update] The story continues here.


Rob Jubb said...

This has to be some crazy crock of shit. Your point about the environment is incredibly well-taken, I think, and should form the basis of a rebuttal of the claim, but more than that, what I want to know is if this has any basis at all, I would expect to see hard scientific evidence of otherwise inexplicable consistent genetic difference between contemporary populations and those of the late middle ages. Anyone making this claim, if it has any real legs, would be getting some actual genetic research done. Unless Clark is, then you'd have to assume he's bullshitting.

J. Carter Wood said...

Thanks Rob, for your comment.

I...want to be a bit more generous to Clark's argument than your first (and last) sentence, partly since my critique is based upon one of his essays and a questionably written review in the NYT and partly because his colleagues in economic history seem to agree that the economic part of his approach has something going for it.

Although, it does seem in some way that without the genetic bit, the argument becomes a rather more redundant: historians have been talking about economic development, capitalist transformations, changing values, etc. for a long time. But...you know, it's not my field, and maybe there's really something outstanding in the his book on that point.

Furthermore, it's possible that in his book, he delves more thoroughly into dialogue with evolutionary psychology, sociobiology, geneticists, etc. Maybe he has evidence of genetic change that goes beyond the rather thin speculations that I think are visible in what I've read so far.

Having read summaries of the book and considered his essay, though, I doubt it.

I also think the possibility of genetic change relevant in some way to behaviour within historical time is not to be dismissed outright. It's something that should be investigated. But I think the way it's raised in Clark's argument is a problem (for the reasons I explain at some length).

It's not enough to say that people's 'values' or culture or behaviour changed at some point in history (we, um, knew that) and then say 'it might be genes' without 1) presenting more evidence for the genetic argument and 2) having a serious discussion of why one thinks the models provided by evolutionary psychologists are wrong.


Rob Jubb said...

The other thing that strikes me, now I think about it more, is, from your presentation and that in the New York Times, is that it doesn't really work as an explanation of why there or then. It's a structural explanation, in the sense that it picks out features of the structure of the thing that underwent the event it's trying to explain, but structural explanations tend to have the weakness that, since structural features generally persist over time, and are shared by other similar things, they don't explain why what happened happened when or where it did. If there was this general dispersion of genetic makeup predisposing people towards the institutions of capitalism through the middle ages, what's special about Britain, and what's special about the late eighteenth century?

J. Carter Wood said...

Yes, the where-and-when question is also relevant. If you look at Clark's paper (I link to it) you will find a lot of economic data which seems to seek to explain the timing.

It does seem to me, though, that any kind of serious argument about why there is an extremely rapid period of economic growth and the surmounting of the subsistence barrier, you are, inevitably, brought back to the 'institutional' history that Clark--judging by the NYT article--seems so eager to distance himself from.

What is the alternative: were all these individuals interacting with each other in the absence of institutions and their genes reached some kind of tipping point in the 1780s?

Perhaps this is fleshed out in the book (and if anyone has read the book, please feel free to enlighten us on that), but (just to be very, very brief) it seems that you're going to have to rely on far less generalising levels of explanation to get an answer to the where-and-why question you raise. And many social and economic and 'institutional' historians have done just that.

I mean, just spontaneously I can think of a variety of 'institutional' (or social) factors that were relevant to England's lead: being an island (the long-term political stability and need to develop an effective navy); the relative continuity of the monarchy, which was gradually over time reigned in by the nobility (the long history of constitutionalism); the (relatively) open nature of the elites; the dissolution of the monasteries (freeing up a lot of land for market-based agriculture); the victory of Parliament in the late 17th century (the resulting stability of banking and the creation of a secure national debt plus investment in war); the relatively capitalist nature of farming and the enclosure movement (grim, but economically stimulating).

I mean, these are all debatable, of course. But, at least they point to why England at that time and place gained such an advantage.

One that, however, was quickly lost as other nations caught up quickly and even outdid them within a century or so.

I suppose Clark could admit that and expand his genetic argument to Western Europe and the countries settled thereby.

But then there's the curious case of Japan...

It _may_ be that Clark has some kind of ideological axe to grind against 'institutional' history. I might have a lot of criticisms of the World Bank and IMF, but his reference to them as 'cult centers' (in the NYT article) sounds a bit...odd.

M said...

Professor Steve Hsu, who is involved with the BGI cognitive genomics project has commented on how Clark's argument could also apply in China (he also notes the book 'The 10,000 Year Explosion: How Civilization Accelerated Human Evolution" is useful for understanding Clark's argument).

"So we have at least two documented cases of the descendants of the rich replacing the poor over an extended period of time. My guess is that this kind of population dynamics was quite common in the past. (Today we see the opposite pattern!) Could this type of natural selection lead to changes in quantitative, heritable traits over a relatively short period of time?

Consider the following simple model, where X is a heritable trait such as intelligence or conscientiousness or even height. Suppose that X has narrow sense heritability of one half. Divide the population into 3 groups:

Group 1 bottom 1/6 in X; < 1 SD below average
Group 2 middle 2/3 in X; between -1 and +1 SD
Group 3 highest 1/6 in X; > 1 SD above average

Suppose that Group 3 has a reproductive rate which is 10% higher than Group 2, whereas Group 1 reproduces at a 10% lower rate than Group 2. A relatively weak correlation between X and material wealth could produce this effect, given the demographic data above (the rich outreproduced the poor almost 2 to 1!). Now we can calculate the change in population mean for X over a single generation. In units of SDs, the mean changes by roughly 1/6 ( .1 + .1) 1/2 or about .02 SD. (I assumed assortative mating by group.) Thus it would take roughly 50 generations, or 1k years, under such conditions for the population to experience a 1 SD shift in X.

If you weaken the correlation between X and reproduction rate, or relax the assortative mating assumption, you get a longer timescale. But it's certainly plausible that 10,000 years is more than enough for this kind of evolution. For example, we might expect that the advent of agriculture over such timescales changed humans significantly from their previous hunter gatherer ancestors.

This model is overly simple, and the assumptions are speculative. Nevertheless, it addresses some deep questions about human evolution: How fast did it happen? How different are we from humans who lived a few or ten thousand years ago? Did different populations experience different selection pressures? Amazingly, we may be able to answer some of these questions in the near future."