I think Rational Choice Theory has a number of advantages over the other theories we’ve touched on, e.g., Bayesian theories or Language of Thought – in particular, its compatibility with evolutionary theory (as explained in the lecture), and the integration of real-world, practical utility into its explanatory potential. I think its greatest risk is that because of this real-world practical orientation, it seems very reliant on a thorough holistic understanding of the given ecological system, and thus easily prone to error in case some key aspect is missed. For example, the explanation for well spread-out birth intervals benefitting the community and therefore kin selection would not make sense in a community that is currently struggling with underpopulation.
The theory seems potentially beneficial to my research on the role of pragmatics in the evolution of evidential expressions because I’m interested in how people use and understand such expressions depending on their indications of varying degrees of reliability in varying communicative contexts. It seems evolutionarily advantageous to have evolved cognitive mechanisms that track degrees of reliability in communicative partners –– i.e., their general trustworthiness –– but are also able to adjust these degrees to communicative context –– e.g., cooperative vs. competitive contexts. It also seems that some types of information content are altogether in need of different reliability assignments, so the content also determines how these cognitive mechanisms function. E.g., specialized information, such as the effects of a certain medicine, will receive different assignments if it comes from a specialist (a doctor), your neighbour whom you trust generally but who’s a lay person, a random stranger, a dodgy webpage, or personal experience. As a result, linguistic expressions that modify these assignments –– evidential expressions modifying the information source, and epistemic expressions modifying speaker commitment –– will also be adjusted in different –– and systematic –– ways according to this contextual variation, and I suspect that a large part of this systematicity can be explained by patterns of communicative utility that fit into inclusive fitness at different levels.