Sunday, 25 November 2012

Tim Tyler: Harms, Information and Meaning in Evolutionary Processes (review)


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

Information and Meaning in Evolutionary Processes by William F. Harms
This book starts out with a 80-page critique of "replicator theories" - a term the author uses to cover the cultural evolution theories of Dawkins, Dennett, Blackmore, Hull and various other players. However, memes seem to attract most of the fire. We hear about how Dawkins backtracked apologetically after introducing memes, playing down their significance. How David Hull was only interested in memes to the extent that they helped him develop a scientific epistemology, and how Dennett got his memes second hand, and just wanted to use them to bolster his concept of the "intentional stance". Memes are based partly on G. C. Williams attempt to rechristen the gene. We hear that this rechristening never caught on, and the word "gene" today still has a totally different meaning in biology textbooks, leaving memes dependent of a dead definition. Further the definition of "gene" that Williams used makes little sense - since it defined genes in terms of selection pressures, which might fluctuate wildly in real life, causing genes and memes to flit in and out of existence. On page 67, Harms writes:

The reader cannot help be aware by now that I do not like the meme concept. It seems, in a word, "superstitious" to me - just the sort of concept that scientific progress will require us to abandon.
There's criticism of the concept of "selfishness" and criticism of the concept of "replication". Harms recognises the "meme's eye view" as a valid perspective, but claims that describing culture in terms of a symbiosis between memes and genes is "awkward". He writes, on page 51:

Methodologically, ontologically, the meme is a mess. For the purposes of popular appeal, however, it could not have been better designed by a Madison Avenue advertising exec. I must nevertheless urge that the only relevance that the meme and its shortcomings have to the application of evolutionary theory is as a distraction, or perhaps an embarrassment.
Harms does make some good points amidst the rhetoric. I agree that G.C. William's definition of a gene is not very usable - though not all information theoretic definitions of the term share the same problem. I don't much like the term "replicator" either. Many have been misled by its confusing connotations of high-fidelity copying. At best, it needs defining prominently by those who use it - to avoid misunderstandings.

However, I think his rejection of the meme is totally unwarranted. I think that all students of cultural evolution should find a sympathetic interpretation of memetics. If you don't understand memes you close yourself off from a lot of important literature on the topic. Further, you then have to find objections to memetics - and there aren't really any decent technical criticsms of memetics: it's a perfectly valid framework for studying cultural evolution with. Failing to understand memes isn't big or clever, it just means you didn't try very hard to understand them.

To respond to the specific criticism that "describing culture in terms of a symbiosis between memes and genes is awkward" - that's mostly nature's fault - the fact that creatures are symbiotic composites of multiple types of agent which exhibit partial genealogical independence is certainly a complication when constructing models. However, looking at the tangles the rival "inclusive phenotype" approach results in, a symbiotic union comes out looking like the simplest model which captures the observed behaviour. Such models of symbiosis have been widely, though sluggishly adopted by mainstream biology - though their impact on academic cultural evolution so far has been pretty minimal.

Having rejected the entire body of existing work on cultural evolution and memetics, Harms is, in his own words sent back to the drawing board in understanding cultural evolution. His idea of a replacement theory is one oriented around cells. He titles a section "cultural transmission as a cellular process", and explains that the cell is the basic explanatory nexus in biology. He says:

You can account for everything that memes are supposed to do in terms of the things that human beings do. The converse does not hold.

I think this proposed project has proved fruitless. Writing off most of the massive existing literature on cultural evolution was misguided. It isn't even clear that Harms is fully aware of the literature he is dismissing. Boyd, Richerson, Cavalli-Sforza and Feldman get one mention, and that says that these folk "seem to find memetics a timely label for an established and respected approach to the study of cultural evolution and transmission". Since I don't recall ever hearing a positive word about memetics from Cavalli-Sforza or Feldman, this raises the issue of whether Harms has actually looked at their work. It certainly isn't clear from the book that he has. Certainly these days, many in the field will roll their eyes at an attack on Dawkins, Dennett and Blackmore. They have a point: why not criticise some of the actual scientists working in the area - rather than their popularisers.

The proposed explanation of cultural evolution that Harms offers - namely "the cells did it" - seems to me like no explanation at all. It is like explaining the function of the brain by saying that it "computed" something. The point of memetics is that it allows you to use the existing theoretical framework of evolutionary biology to understand culture. Recombination, mutation, selection, adaptation, drift, frequency analysis, phylogenetics all apply to culture as much as to DNA-based organisms. We don't really have a corresponding theory of cellular function - since cells are flexible, diverse and can do many things. Cells aren't even really on an appropriate level to offer an explanation of culture. Nor do cells help much with the increasingly common phenomenon of cultural transmission via computers. Harms discards a lot of useful material - and doesn't offer much to replace it with.

I was expecting the rest of the book to expound on Harms' own theory of cultural evolution, but it doesn't. Next he has rather abstract chapters on populations, information theory and selection. The chapter on populations sets up a framework for a kind of universal Darwinism. He observes the generality of selection, discusses the sorting of pebbles on a beach and discusses general population-based models with variation and selection. Harms focuses on philosophical foundations.

Towards the end of the book there are two chapters about a naturalistic approach to meaning. The first chapter is about epistemology, and the second one is about morality. Harms is a philosophy instructor with an interest in ethics, and these seem like the punchline of the book. Harms objects to the idea that you can't go from is to ought. Instead he thinks that evolutionary theory informs morality, without endorsing any particular moral position. Rather he thinks that evolutionary theory helps explain why we adopt a diverse range of moral positions. Harms writes these chapters a bit more passionately than the rest of the book, and I don't disagree with his positions.

However, this whole book is pretty dry and tedious. Though the subject matter is dear to my heart in many places, Harms ladles on Kant, Quine, Locke and Hume in hefty doses, sprinkles on dry mathematics and dissects the philosophical minutae involved until the topics become dry and lifeless. Part of the problem is that I have a scientific background, and Harms is a philosopher - so we aren't speaking the same language much of the time.

Apart from the memetics critique, my favourite part of the book was where Harms discusses Otto Neurath's boat. Harms writes:

Neurath likened conceptual progress to rebuilding a ship on the ocean while traveling in it.
This is a beautiful image that I hadn't encountered before. However, the fact that this was a highlight reflects rather poorly on the rest of the book.


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