In the organic realm, this distinction is foundational in genetics, dividing an organism's heritable information from its products. The distinction defines the domain of genetics.
Various authors have written on this issue - including Peter Turchin, Susan Blackmore, Bill Benzoin, Alberto Acerbi and Alex Mesoudi.
Here's what it says about the genotype–phenotype split on Wikipedia:
The genotype–phenotype distinction is drawn in genetics. "Genotype" is an organism's full hereditary information. "Phenotype" is an organism's actual observed properties, such as morphology, development, or behavior. This distinction is fundamental in the study of inheritance of traits and their evolution.
Wikipedia has it right. To me, this seems simple, clear and applies equally well to both the organic and cultural realms. I've been applying this distinction consistently from the beginning - and it works well in cultural evolution.
I can't help but see the position of others on this topic as being muddled and confused. This post raises the question of why this confusion exists. For me, this seems like cultural evolution 101. The genotype/phenotype distinction is a basic issue that people ought to be able to grasp fairly easily. Yet it doesn't seem to be the case. Why are so many researchers in such a muddle?
Perhaps one of the better resources on this issue is Peter Turchin's posts on the topic. They are a bit of a brain dump and illustrate his thought processes at work. However, it does seem to me that most of these authors don't seem to have considered the issue very carefully. For one thing, many of them don't seem to understand why the distinction is important, and apparently think they can get along OK without it. I think this probably indicates a weak background in evolutionary thinking.
Perhaps one problem is that academics often try to get by without the concepts of cultural organisms or cultural creatures. They try to shoehorn everything into the host's genotype and phenotype. If that's the cause of the problem, this issue is just another nail in the coffin of the extended genotype and the host-centric approach to cultural evolution.
- Turchin: What’s Cultural Genotype?
- Turchin: More on Cultural Genotypes
- Acerbi & Mesoudi: If we are all cultural Darwinians what’s the fuss about? Clarifying recent disagreements in the field of cultural evolution
- Blackmore: The meme machine -Error on BB import