The cumulative open-endedness of human cultures is said to represent a major break with the social traditions of nonhuman species. As traditions are altered and the modifications retained along the cultural lineage, human populations are capable of producing complex traits that no individual could have figured out on its own. For cultures to produce increasingly complex traditions, improvements and modifications must be kept for the next generations to build upon them, and high-fidelity transmission would thus act as a ratchet, retaining modifications and allowing the historical build-up of complex traditions. Mechanisms acting against slippage are important, of course, but cultures also need to move forward for the ratchet to retain anything important. In this paper, I argue that studies of modification-generating processes and the diverse ways they shape cumulative culture have been overlooked. There are many ways that traditions can be modified and, depending on the structure of the cultural traits and of the design space explored by the population, different kinds of modification mechanisms will lead populations to exhibit different evolutionary patterns. I distinguish between action-level and program-level modifications, and argue that with the wrong modification processes, the structure of the design space can constrain the population to wallow in non-cumulative traditions whether or not social learning insures high-fidelity transmission.
Mathieu Charbonneau completed his PhD in philosophy of science at the Université de Montréal (2013). His dissertation examined how the use of explanatory analogies between evolutionary biology and the social sciences informs the construction of a theory of cultural inheritance and structures its explanatory framework. His last paper, “Populations without reproduction,” appears in Philosophy of Science (2014). The current talk emanates from his post-doctoral work on “Cultural Development and Cultural Evolution” at the KLI.