Abstract for: A Co-adaptive Feedback Model of Political Polarization

Political polarization is often characterized as the outcome of an increasingly factionalized and competitive information environment. We argue, in contrast, for an account that views technological change and polarization as a co-adaptive feedback process. Integrating insights from cultural evolution, co-adaptation, and political communication, we propose that political polarization is not simply a byproduct of media technology but shaped by feedbacks between communication platforms and public ideology. We use simple formal mathematical models that capture (a) the unidirectional framework that underlies much of the empirical literature in political communication research in which changes in media drive polarization as well as (b) co-adaptive feedback models in which media technology is also affected by shifts in public ideology. Our findings suggest that a simple unidirectional model—where technological changes directly cause shifts in public polarization—fails to account for the long-term trends in ideological division observed in the US. Instead, we suggest that a reciprocal/co-adaptive model can best account for the persistence and acceleration of polarization, highlighting the importance of endogenous factors in shaping political discourse. We consider the implications of these findings for our understanding of (a) media “effects,” (b) the cumulative, long-term impact of technological change, and (c) innovation in the design of communication platforms in modern representative democracy.