Tuesday 1 July 2014

Do long-lasting cultural habits suggest genetic causes?


In the Boston Review has Philip Cohen reviewed Wade’s “A Troublesome Inheritance” in a piece entitled “Don’t Trouble Yourself”. A couple of points caught my attention. In the last paragraph of his section entitled “Descent into Racism” (this may give you a flavour of the mood) Cohen writes:

Obviously, Wade offers no evidence to support his genetic story of Africa’s poverty because none exists. In the absence of evidence, Wade resorts to homicide statistics. Most countries in sub-Saharan Africa have higher homicide rates than the rich countries, which he calls “a difference that does not prove but surely allows room for a genetic contribution to greater violence in the less developed world.” This contradicts the basic logic of science. As the biologist H. Allen Orr points out in his devastating review, the existence of a difference is not evidence for any one cause of that difference.

Here is the relevant section from Orr: “But if the issue is whether people differ innately in a behavioral trait, a material line of evidence cannot be that people differ in the trait. They may easily differ for other reasons. (Do differences in currency have a genetic basis? After all, there are differences in currency!)”

The argument is true as far as it goes. By leaving out intelligence differences Wade has weakened his explanation of economic differences. However, the currency analogy is interesting. A long established currency would be evidence in favour of something which led to restraint in financial matters for generation after generation. That the name of the British currency is still the “pound” is trivial compared to the fact that it is the world’s oldest currency still in use. So, either solely cultural, or genetic and cultural forces have maintained this store of value since Anglo-Saxon times. The “culture only” explanation is interesting, because it suggests that a habit, once established, will continue, like motion in frictionless space.  This is not entirely silly: culture is a collection of habits, and a habit may persist simply because no-one can be bothered to change it (like calling the currency “the pound”). There are still little roads in the City of London which reproduce paths up from the river landing piers. Now that everyone has built their houses it would be tedious to destroy that street pattern. Worse, it would lead to the loss of some good pubs, for whose customers in the late evening the zigzag nature of the thoroughfare is so well suited.

However, that behavioural inertia would suggest that colonial practices should have stuck in Africa. The railroads should still be there, and all the heavy equipment, all well maintained. Why did that not often happen in Africa? Why did not the African and Indian peoples build on these cultural traditions to make sure there citizens travelled in the carriages, and not on the carriages? Why did Malaysia, post liberation, do better than Kenya, which was predicted at the time to be the likely winner?

So, a difference between genetic groups does not of itself prove a genetic cause, though of course it suggests it, rather in the way that finding health and lifespan difference between social classes suggests that status and resources are part of the cause of the observed differences in life outcomes.

It seems the key attraction of culture as an explanation of behaviour is that it is like mercury, flowing everywhere, adapting to everything, and moving on without leaving a mark. Culture accounts for a people not changing, for a people changing a bit, and then for not changing again.

Although I am not in the prediction business, I wonder what the culture-only protagonists would predict for North Korea? It certainly seems a very different country from South Korea. As Jayman has noted, it may not be a full genetic match, because we do not have genomic data from North Korea. On the basis of the East German experience, if the two countries were to be unified today I predict it would take one generation for the North Koreans to almost catch up with the South Koreans in terms of enterprise and innovation. Specifically, that after 25 years the new generation in the North will be very much like the next generation in the South. All this assumes that the South, as seems likely, supports the North for about 25-40 years. So although the main effect will be over in a generation, this implies that residual effects last two generations. So perhaps we have to say that cultural effects can be reversed in two generations and genetic effects somewhat changed if you implement very strong selection for 16-24 generations.

Is there any state of the world the culture-only hypothesis denies?


  1. Thanks for the nod. Firstly, my response to Cohen contained these gems:

    "Of course, many elements were involved—climate change and geography, population pressure, the presence of various plants and animals, advances in tools and weapons, and human biological evolution—but there is no evidence that a behavioral genetic change was required.

    Actually, this is a stunning reversal of the burden of proof: the idea that these changes can result in behavioral changes sans genetic change is complete speculation without proof. And in fact, there is considerable evidence against this. Not the least being why didn't all these things appear during the previous epoch of climate change, during the Eemian interglacial, when the climate was even warmer than present?"

    "It is equally plausible, though, that adaptive traits emerge from more generic capacities of human intelligence and adaptation and are reinforced through cultural evolution and learning. For example, the ability to comprehend what others are thinking—and what they think of us—could lead to cooperative behavior as an instrumental adaptation even if there is no specific genetic driver for cooperative behavior.

    Let's be clear that this hypothesis would be at least just as 'speculative' as Wade's, no? And as for equally likely, well, why don't different human display equal ability to do so? Why does inequality persist, and why does it follow racial lines? Why do immigrants to new locations generally fail to fully adopt the attributes of the locals? Indeed, why does the racial 'hierarchy' in achievement exist no matter where in the world you look? These are just a few things this 'hypothesis' would have to explain."

    The "culture-only" model seems to be like clay and can mold into whatever shape you want it. If you try to extract falsifiable predictions, like say the stickiness of cultural traditions, once established, and then point to colonial legacies in the developing world – specifically, the failure of the locals to adopt the ways of their overlords – as a counterexample, it switches to the after effects of oppression. If you then ask why countries like South Korea or Taiwan, both colonial subjects, don't seem bothered by this, you get a different answer. If you ask why certain groups in the developed world, say Blacks or Hispanics, fail to absorb the successful habits of the majority groups, you get discrimination as the answer. If you ask why other groups that faced similar conditions, like Jews or East Asians, are nonetheless now successful, you get more ad hoc tripe (or you get people like Amy Chua trying to piece together a wildly inconsistent explanation).

    And of course, few of the culture-only people even touch behavioral genetic data, particularly the fate of adopted children.

    For more on the colonial legacy, by the way, see the work of M.G.:

    Those Who Can See: The New Face of Colonialism

    Those Who Can See: Foreign Policy and the Less Able

    And finally:

    "On the basis of the East German experience, if the two countries were to be unified today I predict it would take one generation for the North Koreans to almost catch up with the South Koreans in terms of enterprise and innovation."

    Well, East Germans haven't yet fully caught up to their Western counterparts, and I suspect they won't do so any time soon.

  2. Twice lost my replies to you.
    Well done for the work which led to the Derb piece.
    When do you sleep?
    Is there a critical period for learning capitalism, say in adolescence

    1. "Is there a critical period for learning capitalism, say in adolescence"

      Good question, I'd say.

  3. Communism should change the population genetically. People who run afoul of the system either die or are severely constrained from reproducing. The longer communism is in power, and the more severe the type, the stronger the effect. Russia would have had a big change, Eastern Europe less, China much like Russia, and North Korea the strongest effect of all.

    1. Communism only ruled Russia for 3 generations or so. So, no, you would not predict a big change.

  4. After a trip to Greece I was stunned by the cultural similarity to my home country (Italy). There is very little communication between the two countries due to a narrow sea and completely different languages and alphabets, yet the customs, the spirit are similar (although not identical, there are many differences).Surely one can explain part of this with the long lasting contact dating from the Greek colonization of southern Italy or the Roman Empire. But how about all the more recent cultural developments and the general way of life?This is also what I observed when I lived in California, where people of north-European stock behaved and dressed like their German or British counterparts. How come that people isolated by hundreds or thousands of miles behave similarly? Perhaps similar genes make people proner at adopting the same cultural elements, picking up signals or selecting the environment that best suits their genetic architecture.

  5. Jayman - "why does the racial 'hierarchy' in achievement exist no matter where in the world you look?"

    That is about as pithy as you can put it.

    1. The article gives a reason that the Nigerians are running to get educations.

      But that reason will be diluted down the generations, I presume. And it will be simply that the parents are pushing the kids because that's what their parents did.

      Then you have a new culture.

  6. The best review of the Wade book was the Winegards' which pointed out that excluding the brain (and behaviour) from general post-Pleistocene evolutionary processes is the special pleading fallacy.

    This does not validate Wade's specific claims, but with so many of the genes in the 10,000 year explosion being linked to the brain, the null ought to be post a pleistocene cognitive evolution.

    It can be hard to tell the role of genetics or 'the power of culture' in personality traits that run in families, so the sane conclusion is its a false dichotomy to attribute it to one or the other. Biocultural evolution means the two are so entwined the very question is irrelevant at the population level.

  7. On the basis of the East German experience, if the two countries were to be unified today I predict it would take one generation for the North Koreans to almost catch up with the South Koreans in terms of enterprise and innovation

    Well, there are 3 factors which make your extrapolation about the Koreas from the Germanies hazardous :

    (1) The North Korean population is much younger than the East German population, which is even older than the western German population. Even before reunification East Germany had lower fertility rates than West Germany, but in the 1990s eastern fertility rates crashed and this has a long-term effect on the age pyramid in the east which is now very skewed.

    (2) The South Koreans are unlikelly to allow free migration from north to south. Germany did allow this, and perhaps 10% of the East German population, most of them prime working-age, absonded west.

    (3) The South Koreans have learnt too much from the German experience. They will not impose immediate monetary union. As you may remember the West Germans immediately announced a 1 for 1 convertibility with the Ostmark -- which was tantamount to economic shock therapy. Almost certainly South Korea would prefer that North Korea undertake very slow, piecemeal reform in the fashion of China, India and Burma, all of which never had a crash following reform but had immediate payoffs in growth.

  8. From historical point of view, the majority, or perhaps overwelmingly majority to be more precise, of cognitive (economical, intellectual, social political) elites of Korean peninsula have been living in the Northern part of Korea instead of the South throughout the history due to the closer proximity to the Central Country - Imperial China.

    It was so 1,000 years ago, it was so 500 years ago, it was so 200 years ago, it was so 100 years ago, it was so just 50 years ago right after the Korean War... probably it may still be the case today even in spite of several IQ points suffered due to its total economical disaster.

    The popular and lazy assumption that the apparently huge per capita income and technological achievement disparity between the North and South Korea today is largely due to the avg IQ difference (instead of ideology) is likely mistaken.

    1. It is lazy indeed.

      I just think that it's really cute that proponents of these ideas peddle them with such confidence.