Diagram showing where cultural evolution in academia goes wrong

Creanzaa, Kolodny and Feldman have a recent document out titled: Cultural evolutionary theory: How culture evolves and why it matters. It has a nice diagram which is useful in illustrating where academia goes wrong in its study of cultural evolution. Here is the diagram:

The caption reads: "Cultural transmission is more complex than genetic transmission and may occur on short timescales, even within a single generation."

This diagram is profoundly misleading. It is based on a view of cultural evolution that doesn't include symbiology. A genes vs culture diagram that includes cultural symbionts on one side, but not genetic symbionts on the other is not showing the whole picture. Humans share DNA between individuals - in the form of bacteria, viruses, yeasts, fruits and vegetables - very much as they share culture between individuals.

Framing the diagram as "Human genes" vs "Human culture" is not comparing like with like. Bacterial and viral genes are not part of the human genome (unless you count the 10% of the human genome that is descended from viral genomes) - but human culture isn't part of it either. On the left, symbionts are excluded, while on the right they are included. It is an unfair comparison which leads to the confusion propagated by the caption. In fact parasite evolution can happen within a single host generation in both the cultural and organic realms. Contrary to the spirit of the diagram you can get genes from peers in both cultural and organic evolution. They are parasite genes, or symbiont genes in both cases. Cultural evolution does not differ from organic evolution in this respect. The idea that in culture you can get genes from many sources, while in organic evolution you only get them from your parents is a popular misconception about the topic.

The whole document has a whole section on "Culture and Microbes". However there is no mention of the idea that culture behaves similarly to microbes and other symbionts. The man-machne symbiosis, for example is not mentioned. Yet symbiosis is the very basis of the whole field according to memetics, one of the very few symbiosis-aware treatments of cultural evolution out there.

The neglect of symbiology in academic cultural evolution mirrors its neglect in the study of organic evolution - until the 1960s. However, cultural evolution's scientific lag means that cultural evolution is far behind, and few academics have even a basic understanding the relevance of symbiosis to the evolution of culture. Maybe these folk never read Cloak (1975) and Dawkins (1976).

I think the history of this misconception of the whole field in academia is fascinating. Why has it lasted for so long and why has it not yet been corrected? I don't have all the answers but I think the origin is fairly clear. Anthropologists wanted a complex theory of cultural evolution, to signal their skills to other academics and prospective students. They may also have wanted to distance themselves from previous attempts to marry evolution and culture. Any mention of biology turns most anthropologists off. Artificially weakening the influence of biology in the theory may have made the theory more palatable to other anthropologists. Still, science is a self-correcting enterprise. Eventually, the truth will out.