Cultural evolution and evolutionary progress

I've written a good deal about evolutionary progress. That evolution is not progressive is a matter of faith for most in the field these days. This idea is basically a mistake. Kevin Kelly offers one of the clearest explanations of why it is a mistake in his book What Technology Wants. Because his exposition is comprehensive and clear, those in doubt should read his treatment.

Massimo presented the opposite perspective recently:

Stephen Gould long ago persuasively argued that there is no necessary direction of increased complexity throughout evolution. The only reason why complexity historically follows simplicity is because life had to start simple, so it only had “more complex” as a direction of (stochastic, not directed) movement. It’s a so-called “left wall” effect: if you start walking (randomly, even) from near a wall, the place you end up is away from the wall.

This "left wall effect" makes a good null hypothesis. However, it's just wrong as a model of real world evolution. Evolution isn't just drift - there's also selection!

I think cultural evolution makes the issue of evolutionary progress clearer. It takes a dyed-in-the-wool post-modernist to argue that cultural evolution is not progressive. Practically everyone agrees that cultural evolution exhibits progress. A curious exception is Alex Mesoudi - who argued against all kinds of evolutionary progress in his recent book on cultural evolution.

I think that progress denialism is unscientific nonsense. It arose as a reaction against unilinear theories of social Darwinism. To me, it seems like a form of political correctness gone mad.