Cultural Evolution:Trial and Error

The Hajnal Line is back!

Update:  Henrich's book mentioned below was also reviewed at Quillette.

Since theories of physical evolution came on the scene we have attributed a teleology, a direction or destination to them, namely us.  As we are the smartest things around, have adapted to live in an enormous variety of places, and there's whole lots of us, we treat ourselves as something of a finished product, that everything else has been pointing to since our emergence.  The Hebrew Bible also declares something similar, that mankind was the last and best thing in creation, and gets to rule over all the other creatures, beginning with the naming.  It is just hard to conceive of ourselves as merely different, having adapted to first one niche and then a series of others in blind fashion.  It's a lovely sentiment that every butterfly or flower is just as much a result of millions of years of trial-and-error as we are, suitable for inspirational posters, but we tend to find this unbelievable as a practical matter.

Nonetheless, when one pushes hard against the premises, it becomes apparent that physical evolution cannot have any internal direction of its own.  It cannot be trying to go somewhere of its own accord. Whether there is an outside force that has ideas where it should go is another entire series of questions.

One consequence of understanding this is a sort of Chesterton's Fence about our own bodies and responses.  We got here by trial and error, which may not be very exalted in thinking about ourselves, but does have the large advantage of having been proven to work. We can eat many things, but not everything; we can accomplish many feats of the body, but not everything we attempt; we can pass through many dangers but not all dangers.  There are no "shoulds" about the body's limitations.  They are or they aren't.  Humans can change their bodies somewhat - vaccination, exercise - and can change their environments considerably so that the body can accommodate to many previous impossibilities.  We can fly in the air, we can live under the seas.

We believe in direction and intention even more in cultural evolution.  We think we have chosen monogamy because it is a good idea some ancestors reasoned out from first principles.  We think that honoring the rights of individuals, eliminating slavery, and establishing consistent law and the consent of the governed are evidence of the brilliance and morality of Western Civ.  And they might be.  Very bright and very moral people did certainly talk about these things a great deal as the changes were taking place, and it certainly seemed to folks at the time that they were being persuaded. That these changes might be merely downstream effects of previous experiments made over hundreds of years is an uncomfortable thought. That we stumbled up out of the muck rather than climbed resolutely doesn't say as much for our character as we'd like to have.

It seems uncomfortably destructive of some conservative ideas.

On the other hand, it is absolutely devastating to some popular liberal ideas.

Old-line conservatives will recognise that there is a good deal of Edmund Burke in this, that a wealth of collective wisdom is contained in our customs and institutions, even if we cannot articulate these clearly or indeed even perceive this.  He was opposed to all sudden change on this basis, that we might easily destroy what we did not understand and not be able to get it back.

There is a new book out, The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous. I have not read it, but I just listened to an extended interview with the author, the social science researcher Joseph Henrich.  Henrich is the chair of the department of Evolutionary Biology at Harvard, so he remains all very correctly culturally neutral and non-judgemental about other cultures, simply recording what he observes.  Nonetheless, it's pretty obvious that we all think things like less crime, more prosperity, and more rights area good thing.  Hard to get around that, really.

The title comes from the problems in social science research around WEIRD subjects.  Over a decade ago, researchers confronted the fact that the subjects of their experiments, drawn largely from freshman at research universities in North America and Europe, were White Educated Industrialised Rich Democratic folks in origin. (Henrich was one of of the leaders of this.) They worried that this group might not be representative of humanity as a whole, neither in culture nor in developmental stage. The move was on to find more diverse subjects from around the world and from different spots even in Western cultures. They are finding that the problem is even worse than they thought.  Not only is that group not fully representative, so that we need to fill out our picture by getting more Peruvians and Pakistanis, the WEIRD group is actually an outlier on many measures, not so representative of humanity at all.

 All this in addition to the replication crisis.

Here is the Hajnal Line, which I used to mention often. 

West of the original red line, John Hajnal noted in 1965 that there were distinctions in nuptuality (marriage customs). Husbands and wives married later and were closer in age, 23 and 26. Not so many arranged marriages between uncles and nieces, you see. A greater percentage never married at all or did not remarry after widowhood. That's lowered overall fertility right there. The blue lines have been added since to even further identify this outlier group. He noted follow-on cultural effects.  Since his time, others have noted a lot of follow-on effects: Greater rights for individuals, especially women. Increased trade and prosperity. Increased literacy, lower crime (especially violent crime), more voluntary associations. More movement of individuals and small families rather than tribal migrations. Henrich is not reductionist, attributing all this to a single factor, but he does note some strong correlations. While there are cultures that promote monogamy and discourage incest, none have insisted on these so powerfully as the Western side of Christianity which became the Roman Catholic, and then Protestant churches. Henrich has a point that forbidding marriage to fifth cousins is extreme, even fanatic, but fairly notes that the upshot was that trust in strangers necessarily had to increase, which selected for traits allowing one to do business with strangers: tolerance, a sense of responsibility to abstract ideals, verbal negotiation and compromise, understanding of simple marking and symbols in order to keep track of what is bought and sold.

In retrospect, these would gradually and perhaps even inevitably lead to trade, prosperity, individual rights, higher value for women, voluntary associations and all the rest.  The Roman Catholic Church did not have all these outcomes in mind when they set their strict sexual rules, but that's what we got. (I think one can read some of these projected outcomes in the writings of Christians and from the Bible directly, but leave that be for the moment.  It is true that the whole suite of cultural behaviors was not predicted by the Church.)

Polygamy results in a much larger pool of males with poor mating prospects. In a monogamous system, males can keep their head down and work hard, and learn to make themselves acceptable to either a woman or her family with a fair hope of success. But in a polygynous system males have to seriously jump the line.  A 10% improvement in one's acceptability isn't enough - you need 40%.  This creates a culture of high-risk behavior in low-status males, which leads to more crime.  Henrich notes that such societies do in fact have more crime.

This is familiar to those who read up on Human Biological Diversity, here and elsewhere, a decade ago.  HBDChick, whose blog is defunct but I think still tweets, was the first to alert me to the idea that the RCC discouragement of cousin marriage, which for some reason was obeyed more faithfully in Western Europe than anywhere else, had enormous impact on culture and likely even genetic traits. She also credits manorialism, BTW. She also would add a green oval from Kent and East Anglia over to NW Germany, including the Low Countries and northern France as a hyper-Hajnal area.

Suggesting recent trait selection always leads to charges of racism, but the numbers are what they are, and the DNA is what it is.  Steven Pinker, David Reich, Robert Plomin and many others are uncovering the evidence of genetic influence on all behavior, gently and artfully pointing out that something WEIRD seems to have happened in Western Europe. (Even the New York Times has reviewed the new book and said good things about it.  They will likely have to apologise later.)  Henrich shows that is also a two-way street. As that Hajnal line also lines up with y-chromosomal R1b-majority areas, long preceding anyone obeying anything Roman Catholic, one has to wonder if there was some predisposition to monagamy and avoidance of incest there. We can read greater individuality, voluntary association, and rights for women back into those cultures, but there is danger of convenient interpretation, seeing what we want with such things.

We don't like this, as I noted earlier.  We like to think that we turned to agriculture because we reasoned it out and decided to put some of those seeds to grow  in a good place for next year, and noticed little advantages generation after generation, choosing the biggest seeds or the ones that wouldn't come off until you shook them, improving the stock over a few generation or maybe a few centuries.  The archaeological record now shows that the improvement in cereals took thousands of years, meaning that a) it started earlier than we thought, and b) was trial-and-error and seldom intentional, if ever.  The ones who had better grains survived a bit better but likely not even noticeably compared to tribes over in the next valley.  Thoughts of survival focused more on drought, warfare, and natural disasters.  This is not surprising. None of us notices if the people in the next county have 1% greater fertility or longevity.