Basically it argues that humans don't behave as the theory of evolution dictates. For example, the more resources you give a human, the fewer children they have.
I think this article nicely illustrates the confusion associated with a lack of understanding of cultural evolution. Almost everything in the article makes me think: "yes: but only if you ignore cultural symbionts".
It's well-known that parasites can reduce host reproduction - and even drive hosts extinct. The demographic transition is driven by cultural symbionts that reduce host reproduction. This has been extensively modeled by cultural evolution enthusiasts. This isn't contrary to the theory of evolution - you just have to include the evolution of memes in order to understand it.
If you add resources to a human population the memes absorb the resource faster than the human hosts do - and more memes often means less host reproduction.
Something very similar happens in the organic realm - if you add sugar to a human population. A little sugar might help with reproduction - but beyond a certain point, fertility begins to decline. Instead of making more human genes, the sugar fuels the reproduction of gut microbes at the expense of the genes of the human host. The host's belly swells up to accommodate them all. Eventually the host is effectively sterilized.
This all illustrates the dictum: Nothing in human evolution makes sense - except in the light of cultural evolution.
- Boots, M. and Sasaki, A. (2002) Parasite-driven extinction in spatially explicit host-parasite systems.
- Hwang T.W., Kuang Y. (2003) Deterministic extinction effect of parasites on host populations.