Exposure versus Susceptibility in the Epidemiology of "Everyday" Beliefs

Abstract

This paper shows that epidemiology, an approach developed to study the social communication of biological information, can be instructively applied to the diffusion of "endemic" cultural beliefs. In particular, I examine whether exposure to information (as determined by physical and social access), or susceptibility to belief (a variety of cognitive biases underlying belief adoption) is more important in determining the distribution of food taboos in an oral society from the Democratic Republic of Congo. Matrix regression techniques are used on optimally scaled cultural similarity data to infer which social and psychological characteristics of the participating individuals are correlated with a higher probability of taboo transmission between them. Results indicate that, despite a lack of mechanized transportation, access to information in this population is nearly universal. Constraints on belief adoption rather than on information flow are much more important in determining the intra-cultural distribution of food taboos. At least for one class of taboo, belief susceptibility is a function of an individual's social role rather than any intrinsic quality of the individual or the believability ("virulence") of the cultural trait. Nevertheless, the processes underlying the dissemination of both cultural traits and pathogens, considered as replicating units of information, appear close enough to justify using epidemiology as a common framework for investigating cultural and biological diffusion.