Sunday, 15 July 2012

Pinker reiterates his critique of memetics

Pinker reiterates his critique of memetics - as follows:
The other reason applies as well to Dennett's own defense of the theory of memetics. Human cultural innovations are quite different from the blind mutation and recombination that supply the raw material for bona fide natural selection. I'm happy to concede that this is a difference in degree. Sure, natural selection does not require blind mutation; it can add value to intelligently designed or directed variants. And sure, the brainchild of a single innovator generally must be tinkered with and combined with other innovator's brainchildren through social networks before it is of any use.

But what a difference in degree! Genetic mutations and recombinations are strictly typographical, twiddling the As, Cs, Ts, and Gs with no foreknowledge of their effects on the organism's interactions with the world. As Dennett, Dawkins, and Tooby emphasize, natural selection is an astonishing theory because it explains how biological design can emerge from this mindless background. But the trillion-synapse human brain, even when it is daydreaming, tinkering, riffing, brainstorming, or jamming, does not blindly substitute one phoneme or word or ingredient for note for another and live or die by the consequences. Genetic mutations are monkeys at a typewriter; human innovations are not. Millions of years of natural selection for know-how have equipped the brain to develop mental models of the world that prune the tree of potential innovations to an infinitesimal sliver of the space of typographical possibilities. To reduce the function of the human brain to a mutation generator, even a "nonrandom" one, is to bring back B. F. Skinner's empty organism and to miss out on the outsize adaptations that make human cognition, cultural learning, and sociality so unusual in the animal kingdom. It's not that analogues of natural selection have nothing to add to our understanding of cultural change. But unlike the case of genetic evolution, where selection assumes the full burden of generating adaptation from the vast space of genetic possibilities, most of the work done in exploring the space of logically possible ideas must be attributed to the organization of the brain.

I think the key idea that Pinker is missing is the idea that natural selection and Darwinian evolution also explains the operation of the brain. Not just in the sense that evolution of DNA genes is responsible for the generation of the brain over millions of years, but in the sense that the brain employs copying, variation and selection (i.e. evolution) ubiquitously in its moment-to-moment operation - and its powers as an optimisation engine arise from that fact that it implements an evolutionary process. That the brain evolves in this way has long been recognised by Skinner, Calvin, Campbell, Cziko - and many others. It is a central idea in Universal Darwinism.

Pinker concludes by saying:

If you reduce these ideas to simple tokens that are spread by contagion or multiply at different rates, and don't considering how their content affects the beliefs and desires of human protagonists, you will end up with a seriously incomplete understanding of cultural change.
However, this is an obvious unreferenced straw man. Nobody proposes ignoring how memes affect the beliefs and desires of their human hosts - except perhaps in the case of highly simplified models.

Alas, the "seriously incomplete understanding" is that of Pinker.


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