A book chapter written (now almost two years ago…) by Magnus Enquist, Stefano Ghirlanda, and myself has just been published. It sums up pretty well part of the research I was carrying with the Centre for the Study of Cultural Evolution in Stockholm.
We explored the concept of “regulatory traits”, that is, cultural traits that are both socially transmitted (they are “cultural”), and influence directly (“regulate”) cultural dynamics. While the distinction between regulatory and non-regualtory traits is not always clearcut (potentially everything one learns could influence her future behaviour), the regulatory aspects of some traits seem particularly evident. For example, consider the regulatory trait “learning from school teachers”. This is both socially transmitted (parents do an effort to convince their children that learning from teachers at school is good) and influences directly – at least this is what parents aim for – cultural dynamics (children will listen to what teachers say at school). Again, teenagers may attempt to persuade their peers (“socially transmitted” part) to not listen to adults (“regulatory” part).
At a more abstract level, the same propensity to engage in cultural learning can be subjected to cultural influence and hence be a regulatory trait (you learn from others whether – or how much – to learn from others). Although this may seem not more than the starting of an headache-y riddle, we showed previously that, if this is the only force working in a system, the paradoxical result is that everybody will converge to not learn from other at all. Why is it so? “Conservative” individuals (i.e. individuals who do not engage in cultural learning) have indeed an inherent advantage as cultural models in respect to “open” individuals (i.e. individuals who engage in cultural learning): when a conservative individual will meet with an open one, it is more likely that the open will copy the conservative than vice-versa, pushing the population towards conservatism. Another way to think about this: imagine a group of, say, ten people, with t-shirts of different colours, playing the (well-known, of course) “copy the colour of my t-shirt” game. One of the individual will never copy others, while the other nine have a variable probability to engage in social learning. The only possible outcome of this game, given enough repeated iterations, is that everybody will end up wearing the same colour of the conservative individual, even if there is nothing in his t-shirt that makes it better than the others.
Even though the outcomes described above are the product of extreme, and scarcely realistic, conditions, regulatory traits-driven dynamics can interact with other aspects involved in cultural transmission, generating more complex, and – hopefully – interesting, outcomes (we explore, among others, in-group biases and fashion-like dynamics). Conservatism itself is, in my opinion, an underestimated force with regard to the spreading of cultural traits. All other things being equal, a cultural trait that makes its bearers more conservative will be more likely to have success than a cultural trait that does not (I like to think in this term to the first of the ten commandments, which sounds “thou shalt have no other gods before me”, rather than “look around for other gods, and you’ll see I am the coolest”).
Moreover, a part from having effects in cultural dynamics, regulatory traits represent a difference between cultural and biological evolution. This is a “hot” topic in modern cultural evolutionary theory so I do not want to go in depth here (let me just say at least that I think it is interesting to study also the differences between the two evolutionary processes). “Rules” of genetic transmission tend to not be under genetic control, and models of cultural evolution inspired by evolutionary biology tend to consider the rules of cultural transmission (for example the propensity to learn from others) in the same way not under “cultural control” (they are usually considered under genetic control). However, the fact that cultural information can be transmitted in many different ways creates the opportunity to regulate the flow of information in a fine–grained and context–dependent way, and regulatory traits can have a role in this process.
Acerbi A., Ghirlanda S., Enquist M. (2014), Regulatory traits: Cultural Influences on Cultural Evolution, in: Cagnoni, S. et al. (Eds.), Evolution, Complexity, and Artificial Life, Springer, pp. 135 – 147