Thursday, 1 September 2011

Tim Tyler: Can memetics explain creativity?

Transcript: Hi! I'm Tim Tyler - and this is a video which responds to one of Steven Pinker's criticisms of memetics - the one where he questions whether it can make sense to talk of Romeo and Juliet evolving into West Side Story.

In my book on memetics - which is out now - I take a look at some of the critics and criticisms of memetics. Steven Pinker is one of these critics. Pinker expressed a number of objections to memetics in a 2009 Harvard lecture. Here we will look at his assertion that the process of evolution of Romeo and Juliet into West Side Story has little in common with the process responsible for industrial melanism. Here's Steven:

[Steven Pinker footage here]

Steven says that to compare the way in which West Side Story was developed from Romeo and Juliet with the way a white moth changes into a black moth as part of the process of industrial melanism would be misleading.

So: what these processes have in common is that both are instances of an evolutionary process - consisting of copying, variation, and selective retention.

However, evolution takes place using a wide range of mechanisms, and there is no particular reason for any two evolutionary processes to be particularly similar.

For example, the K-T extinction event is is not much like industrial melanisim either - though although both are still forms of evolution.

Similarly variation in evolution arises using a range of mechanisms, and there should not necessarily be any expectation for any two of them to look very similar.

So, for example: comsic rays are quite different to ploidy-changing events in polyploid crops, which in turn are quite different from endosymbiotic symbiogenesis.

Pinker is essentially pointing out that memetics has a hord time handling creative processes. Saying that memetics does a poor job of explaining human creativity is actually a common complaint of critics of the field. It certainly isn't the strongest point of memetics - but there is a good reason for that. Memetics is strongest in the area of population memetics. So, for example, it does an excellent job of explaining why the Indo-European languages form a branching tree with a common ancestor, why long-isolated islands tend to have backwards cultures, why high population densities results in greater contagious spread of ideas - and so on.

From the perspective of population memetics, a single creative act is just a type of mutation. Now we can model mutations in ideas - but, because we don't yet have a complete model of the mind - and we don't know how to build a mind - the results are not that great. The models which are used are typically much the same ones that are used by conventional psychology - and don't owe much to genetics. Population memetics - which is really the most successful branch of memetics -typically doesn't bother very much with modelling mutation - and instead it just tracks population-level processes. Treating the mind as a black box, and mostly ignoring what goes on inside it has been a wildly successful method, and has resulted in substantial progress of population memetics within academia - much as the exact same strategy has done in population genetics.

Of course, West Side Story was not just one creative act, but dozens of them, and I am sure there was a great deal of trial and error in getting the right dance moves, music, lyrics, and so on - so it does make reasonable sense to compare it to other evolutionary processes - but I think we should start by making some effort to compare like with like.

In the case of Steven's example he has selected a case where there are some similarities - but also some distracting differences. In both industrial melanism and the creation of West Side Story we have an ancestral form adapting to a different modern environment. However, there are also some differences, which interfere with the comparison by introducing irrelevant noise.

In industrial melanism, single lineages independently changed form - whereas West Side Story consists of quite a mixture of different cultural lineages. The script had one set of cultural parents, while the choreography, the lyrics and the music each had their own different sets of ancestors with their own separate descendants and life cycles. So, West Side Story is more like a complex symbiosis than a single species. One might compare it to a patch of forest. In keeping with the theme of adapting to a modern environment, we might imagine a forest ecosystem attempting to invade a modern city environment. I think this is a fairer comparison - which does a better job of attempting to compare like with like.

Steven points out that one of the differences between these systems is that West Side Story is partly the product of memetic engineering. That is a fair enough difference to point out. Engineered systems are indeed a bit different from ones that are not engineered. To produce a comparable forest, one would have to introduce genetic engineers to assist the forest creatures in adapting to their new environment. Of course the mere introduction of some genetic engineers doesn't stop the forest evolving. Using engineering speeds up evolutionary change, much as deliberative selective breeding did before it, and much as unconscious selective breeding did before that - but it doesn't stop the forest from evolving and changing and obeying the rules of evolutionary systems.

One of the best ways of visualising this situation is to consider evolutionary change as taking place in systems involving a range of different intelligences. The stupidest type of evolution involves creatures with no brains that evolve using largely undirected mutations, then we have creatures with brains, and creatures whose brains implement virtual worlds which can simulate the future, and then highly intelligent creatures which have mastered engineering.

Pinker is comparing systems at opposite ends of this intelligence scale, and claiming that variation arises in them in dissimilar ways. That's true - the systems vary in how much intelligence is involved, and the smarter systems can make use of more interesting forms of variation. However both systems still evolve. They exhibit copying, variation and selective retention. So, evolution is what these processes have in common.

Although the details of the way in which variation arises are different in these two systems, that is perfectly acceptable because variation in evolution arises in a large number of ways, which can be very different from one another. We already know and understand that. It is absolutely fine for variation to arise in many different ways that do not necessarily resemble one another. It does not represent some sort of problem.

"Evolution" simply does not imply a lack of intelligence. That is just a basic misunderstanding of what the term "evolution" means. Yes, ignorant creationists who want to introduce intelligence into evolution should be combatted, but not by changing the definition of "evolution". That term is clearly explained in the evolution textbooks. Intelligence is not excluded. It doesn't get a mention, and nor should it. Brains no more prevent evolution by thinking than our kidneys prevent evolution by filtering our blood.


Pinker's entire critique may be found here.

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