Sunday, 18 November 2012

Tim Tyler: Cullen, Contagious Ideas (review)


Hi! I'm Tim Tyler, this is a review of this book:

Contagious Ideas: On Evolution, Culture, Archaeology and Cultural Virus Theory by Ben Sandford Cullen

Ben was writing this book when he died unexpectedly in 1995. His manuscript was subsequently combined with parts of his doctoral thesis on the topic, edited together and published in the year 2000.

In the book, Ben puts forwards his own theory of cultural evolution - which he calls the "Cultural Virus Theory". Though Ben says his theory was developed independently of memetics, the two theories are complementary - a fact that is recognised in the book.

Ben starts out with what he calls the cultural virus critique. He devotes his first four chapters to looking at alternative theories of cultural evolution, and explaining what's wrong with them. The first chapter criticises social Darwinism, the second criticises Ed Wilson's sociobiology, and the third and fourth chapters criticise cultural selectionism.

The critique of Ed Wilson's sociobiology is pretty accurate. Wilson's attempt to reduce cultural phenomena to things that benefit genes looks misguided retrospectively. However, since this book was published, Wilson's brand of sociobiology has mostly faded away - and been largely replaced by a more politically correct form: "evolutionary psychology". In avoiding all mention of differences between humans, this doesn't so much attempt to explain culture in genetic terms but rather belittles its influence and ignores it. Its practitioners typically don't have an understand cultural evolution.

The third and fourth chapters mostly look at what Ben calls "American Cultural Selectionism". This is characterised by explaining culture in terms of human traits, and tracing their passage between humans in terms of "oblique" and "horizontal" transmission of those traits. Ben classified these models as being "inclusive phenotype" models - since they include traits encoded by genes and memes in the phenotypes of human individuals. Rather than featuring distinct cultural individuals, phenotypes and populations - like memetics does - the "inclusive phenotype" models combine cultural and genetic influences within one human phenotype - in what Ben patronisingly refers to as a "bio-cultural muddle".

Of course, since cultural traits exhibit geneaolgical independence from the human germ line, modeling them in terms of a combined phenotype makes very little sense. It is rather like modelling a human population infected with smallpox by considering the DNA of the human hosts and the DNA of the smallpox virus as a single phenotype influenced by both sources, with the smallpox traits exhibiting horizontal and oblique transmission. Then you can consider one group of humans with the "smallpox trait" wiping out other groups of humans that lack it. However, biologists don't tend to do this much because of Occam's razor. Rather considering one phenotype, with multiple inheritance pathways, is simpler and neater to consider the smallpox virus to have one phenotypes - and the human hosts to have another phenotypes - and to consider their relationship to be a parasitic symbiosis between the two distinct entities. The exact same approach works very effectively with cultural inheritance.

Ben's critique of position of the American Cultural Selectionists is pretty devastating, in my opinion. It's much the same critique as I have previously offered, but spread out over two book chapters. I tend to use the term "extended genotype" instead of Ben's "inclusive phenotype" - but we are essentially talking about the same idea. Ben's critique remains relevant today - since the strain of American Cultural Selectionism involved is associated with the work of Cavalli-Sforza, Feldman, Boyd, Richerson, Durham and Rindos - and it has subsequently gone on to become the most popular form of cultural evolution within academia. Understanding where these folk originally went wrong is important to understanding the history of the field. A better model of cultural transmission invokes cultural symbionts. This has previously been previously described by Cloak and Dawkins - in 1975 and 1976 respectively.

While a single "inclusive phenotype" with genetic and cultural traits isn't all that much use for modeling cultural evolution with, one thing it is good for making byzantine mathematical models that appear to be sophisticated and original. The correct perspective on cultural evolution reuses the same concepts of symbiosis that already exist in the realm of organic biology. However it requires practically no new science - and so isn't a great source of revolutionary papers. By claiming culture exhibits the strange new phenomena of oblique and horizontal transmission that were absent from the organic realm, the American cultural selectionists had found an excuse to develop their own innovative models of the process of cultural transmission. If you think of academia as a place where affiliations with prestigious individuals are cultivated, these complex mathematical models make a lot of sense - since advanced mathematics is an impressive thing. However, the combination of an awkward, complex model and the associated reams of complex mathematics had an unfortunate side effect: few understood the work. As a result, the important science of cultural evolution has stagnated in academia for decades.

How has American Cultural Selectionism survived for so long - when it is based on such misguided models? Some of the practitioners involved do seem to have tipped their hats hat towards the perspective of symbiosis in the mean time. The books on the topic from the 1980s typically made no mention of symbiosis, viruses, parasitism, epidemiology - or any of the tools you actually need to understand cultural evolution. However, if you fast forward to the 21st century, you will see occasional mentions of these things in the associated academic literature - where they are often described as being "analogies". This takes the sting out of the type of criticism given here - since the defenders of the theory can point out these occasional passages related to symbiology and say: look, we actually have that covered. However the symbiology remains little more than a cosmetic veneer. The incorrect "inclusive phenotype" model is still there, misleading a new generation of researchers about the nature of cultural transmission in humans.

After explaining the problems with the competing theories, Ben goes on to lay out his own proposal: the "Cultural Virus Theory". It is a symbosis-based theory - a lot like memetics, but with its emphasis on cultural phenotypes - rather than heritable information. Ben explains that memes act as the genotype, while his cultural virus idea plays the role of phenotype in his model. He says he thinks the virus perspective is more palatable than considering artifacts to be organisms - since historically most artifacts have hijacked copying machinery inside humans to ensure their own reproduction. Ben doesn't seem too worried about the negative connotations of culture as a virus. There are some helpful viruses and many viruses go on to become part of the germ line of their hosts - so viruses aren't all bad.

For me one of the most interesting parts of the book was where Ben expounds on the idea of cultural kin selection and cultural eusociality. Ben has a whole chapter on cultural eusociality - where he explains that many of the cultural artifacts that we see that don't conspicuously reproduce are really sterile worker individuals. He says that things like chairs and tables don't directly reproduce, but instead they act to divert resources (particularly money) back towards the factory that produced them - and the factory plays the role of "queen". Ben's ideas about kin selection and eusociality in culture are mostly good - and were well ahead of their time. However I think that in places they may go a bit too far. When you have a distributed organism with sterile castes it is sometimes best to describe it as one big organism - rather than as an advanced form of social organisation. Also distributed phenotypes need not necessarily be classified as cultural individuals - they could be more like hair or nails, feathers or tusks. My nit picking aside, Ben is pretty clearly correct about the ubiquitous nature of cultural eusociality - and many of his examples of it are good ones.

Lastly I should probably say some bad things about the book:

  • The book starts off slowly - and I didn't get along with much of the material about evolutionary progress and Lamarckism in the first chapter.
  • Ben was an archaeologist and he uses examples from archaeology ubiquitously in the book - but it is a general book about cultural evolution, and he should probably have cast his net wider when selecting examples.
  • The idea that cultural entities act as viruses may be easier to swallow than the idea that they are partly-independent symbiotic fully-blown organisms. However, it is difficult to deny that memes create their own manufacturing facilities - rather than simply hijacking the brains of human hosts. Computers and the internet are the product of memes, much more than genes. The "cultural virus" perspective is too narrow - as well as having undesirable connotations of parasitism and host harm.
  • Ben talks quite a bit about cultural predators preying on humans. It turns out that his definition of a predator is that it is a large parasite - and it makes no mention of quickly devouring the victim for food. Most require predators to kill their hosts.
  • Most of the book is fairly readable - but with the material imported from his thesis, the readability goes through the floor.
However, overall, this book is pretty great. It's nice to have a thorough critique of American Cultural Selectionism available in print - and Ben was a pioneer in applying the theories of kin selection and eusociality to cultural evolution. If academics had been smart enough to follow in Ben's footsteps, the theory of cultural evolution wouldn't be in anything like the mess it is in today - but alas, that isn't what actually happened - and there's still much work to be done.


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