Second, Darwinian evolution is usually seen as a process that works over very long periods of time, with consequences for humans that we can observe only by looking far into the past.
Well, yes, but Clark is careful not to insist that it is Darwinian evolution which is the mechanism by which the change came about.
One frustrating aspect of Clark’s argument is that while he insists on the “biological basis” of the mechanism by which the survival of the richest fostered new human attributes and insists on the Darwinian nature of this process, he repeatedly shies away from saying whether the changes he has in mind are actually genetic. “Just as people were shaping economies,” he writes in a typical formulation, “the economy of the preindustrial era was shaping people, at least culturally and perhaps also genetically” (emphasis added). Nor does he introduce any evidence, of the kind that normally lies at the core of such debates, that traits like the capacity for hard work are heritable in the sense in which biologists use the term.
Quite, so he’s not in fact talking about Darwinian evolution then, so why blame him for not proving that it was caused by Darwinian evolution?
The issue here is not merely a matter of too often writing “perhaps” or “maybe.” If the traits to which Clark assigns primary importance in bringing about the Industrial Revolution are acquired traits, rather than inherited ones, there are many non-Darwinian mechanisms by which a society can impart them, ranging from schools and churches to legal institutions and informal social practices.
Indeed, and we’ll come to that.
But if the traits on which his story hinges are genetic, his account of differential childbearing and survival is necessarily central.
Ah, and there is the central error in Friedman’s argument. For Darwinian evolution is not in fact the only sort of evolution that has been posited, nor is it the only form of evolution which we can argue actually works.
Now, let me back up slightly here. I’m not about to get all kooky on you and insist that because your father learnt to play the guitar then so can you already play the guitar via your genes. But there has been another form of evolution posited, Lamarckian. As it turns out, with the genetic attributes of humans and other animals it turns out to be wrong. But in Deirdrie McCloskey’s review of the same book, the issue is indeed nailed as being entirely central to the thesis (and no, she doesn’t agree with it):
…unless they fit his notion of the material if social inheritance of acquired characteristics (“and perhaps even the genes,” says he).
The inheritance of acquired characteristics is, in evolutionary terms, referred to as Lamarckian: and as above, with reference to genes, it’s wrong. However, with reference to culture it most certainly is not wrong.
No, I’m not going to try and prove that culture is transmitted in a Lamarckian manner. Rather, I’m going to prove that you and everyone else already believe it is.
For I think we all agree that the children of teenage mothers are more likely to themselves become teenage parents? That is the inheritance of an acquired characteristic. We note that children who grow up in a home without books do badly at school: and then go on to note that those who do badly at school tend to have few books at home to instruct their own children. We note that the middle classes tend to transmit their social success across the generations: it’s most unfashionable these days to attribute that to genes, rather, to social networks, to the privilege that a secure upbringing and a decent education provide. We note that children whose parents have a university education are more likely to get a university education themselves. Anyone pondering the family networks that infest UK journalism, or the Law, will be observing exactly the same thing. No, we don’t believe that the ability to write leader columns has been genetically transmitted from Lord Rees Mogg to Annunziata Rees Mogg (he at The Times, she at The Telegraph: and having once read one of hers where she refers to "sclerosis of the liver", if we did I’d be expecting someone to be having a very serious and intimate chat with Lady Rees Mogg sometime soon) but we do indeed believe that a combination of education and the extended network of the family have contributed to the daughter following in the old man’s footsteps.
Indeed, this is one of the arguments forcefully put forward againt the existence of private schools in the UK: that they permit the transmission of exactly this form of cultural inheritance and thus privileged positions.
So we believe this about our society now: that attitudes, mindsets, extended networks, are indeed transmitted across the generations, not via Darwinian evolution, but in a way that can best be described as Lamarckian. The inheritance by the next generation of characteristics acquired by the previous one.
So we all already actually agree that Clark’s mechanism is indeed a possible one (I personally regard it, now that’s he’s written the book to explain it, as obvious, but as I didn’t see it before I read the book perhaps not that obvious.): all he needs to really prove is that the people who were transmitting the petit- and not so petit- bourgeois cultural values were indeed outbreeding those who didn’t and the basic argument seems secure. Those bourgeois cultural values were indeed spreading through society via an evolutionary mechanism, just that of Lamarck, not Darwin.
Now, whether that actually caused the Industrial Revolution is another matter, but the transmission mechanism is one that, as above, we all already think is true.
Update. One further thought. I’m really not sure where that idea that Darwinian evolution is only evident in humans over very long periods of time comes from. We need to divide evolution into two different things. The first is the accumulation of random mutations which lead to diversity in the population (which in itself can be divided into two. Those that kill the fetus or child, which are most of them, and those that don’t). This does indeed take a long time and it happens at a reasonably well known rate. So much so that we actually use the existence of such diversity to count backwards and tell us when populations split in the past. Now most such mutations (those that don’t kill) make very little or no difference at all to reproductive success. Others do make a difference. But there’s a third set and those are those that make no difference now, but might at some point in the future. Yes, the accumulation of these mutations does indeed take a long time.
Well, you might ask, how can something not make a difference to reproductive success now but do so in the future? This brings us to our second "thing" about evolution. It’s the changing environment which determines which traits lead to that increased reproductive success. Sure, things like melanin enhancement in skin to deal with sunnier climes take a long time to become evident. But environments can change rather rapidly.
For example, what if there were some random mutation that conferred immunity (or an increased chance of survival) to smallpox? Or bubonic plague? I’ve no idea whether there is or has been (that there are such mutations for better immune systems is obvious, but they proffer immediate increased success, except where they don’t) but I wouldn’t be at all surprised if there had been. And then in Justinian’s time (around 500 AD, for smallpox) or the 1350s, for bubonic plague, possession or not of those genes becomes very evident in a very short period of time. Those with them are still alive, those without are not.
Yes, OK, it’s a quibble, but it’s a boring Monday afternoon here.