Phenotypic hitchhiking

I've previously written about memetic hitchhiking. This is one of the main ways in which memes catch rides with other memes - via memetic linkage.

However, there's also another type of hitchhiking involved with cultural evolution: phenotypic hitchhiking. This is like the hitchhiking done by parasites and commensuals in the organic realm - where snails hitchhike on birds' feet and lice hitchhike in mammalian hair. Unlike memetic hitchhiking and genetic hitchhiking, this type of hitchhiking doesn't really depend on linkage. It takes place between symbiotic partners, rather than within a single organism.

Symbiotic hitchhiking can be categorized as follows:

• Organic hitchhikes on organic - e.g. a snail on a duck's foot;
• Organic hitchhikes on cultural - e.g. a mouse on a boat;
• Cultural hitchhikes on organic - e.g. memes in a human mind;
• Cultural hitchhikes on cultural - e.g. sticker on an advertising hoarding.

The idea appears in Bettinger, Boyd and Richerson (1994). They say:

Hitch-hiking, however, does not necessarily require any linkage in the physical sense, only an initial statistical association. Because of this, genes can easily hitch-hike with cultural innovations or vise versa.

A paper by Whitehead, Richerson and Boyd (2002) also discusses "cultural hitchhiking".

The 2011 academic paper "Religion, fertility and genes: a dual inheritance model" discusses a case of genes for religiousity hitchhiking of cultural religious practices.

While academia seems to have grasped "phenotypic hitchhiking" involving cultural variation early on, it doesn't seem to have cottoned on to memetic hitchhiking very well at all. Yet this is surely the most common and important form of hitchhiking in cultural evolution.

Referring to genes hitchhiking on cultural variation as "cultural hitchhiking" seems like bad terminology - since there are also other kinds of cultural hitchhiking that are take place. Genes hitchhiking on memes is just one type of hitchhiking involving culture.

References

• Bettinger, Boyd and Richerson (1994) Style, Function, and Cultural Evolutionary Processes
• Whitehead, Hal (1998) Cultural Selection and Genetic Diversity in Matrilineal Whales
• Whitehead, Richerson and Boyd (2002) Cultural Selection and Genetic Diversity in Humans
• Rowthorn, Robert (2011) Religion, fertility and genes: a dual inheritance model
• Tyler, Tim (2011) Memetic Hitchhiking