Friday, February 26, 2016

Cultural Evolution Overwhelmingly Prioritizes Social Prestige

Models of cultural evolution can accurately model processes such as language shift and religion shift by people who have a choice (not necessarily an unfettered free one, however), regarding their decisions to adopt a new language or religion. A generalization of those models finds that social prestige, defined as the extent to which one's cultural trait has been picked up by others, is pretty much the exclusive component of selective fitness in cultural evolution.
This paper seeks answers to two questions. First, if a greater social activity of an individual enhances oblique (i.e. to non-relatives) transmission of her cultural traits at the expense of vertical (i.e. to children) transmission as well as family size, which behavior is optimal from cultural evolution standpoint? I formalize a general model that characterizes evolutionarily stable social activity. The proposed model replicates the theory of Newson et al. (2007) that fertility decline is caused by increasing role of oblique cultural transmission. Second, if social activity is a rational choice rather than a culturally inherited trait, and if cultural transmission acts on preferences rather than behaviors, which preferences survive the process of cultural evolution? I arrive at a very simple yet powerful result: under mild assumptions on model structure, only preferences which emphasize exclusively the concern for social prestige, i.e. extent to which one’s cultural trait has been picked up by others, survive.
Roman Zakharenko, "Nothing else matters: Evolution of preference for social prestige", Mathematical Social Science (February 23, 2016).

This broad theoretical result has applicability to both the modern evolution of culture and the cultural, linguistic and religious shifts experienced historically and into prehistory.

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