An Argument Communication Model of Polarization and Ideological Alignment

This multi-level model of opinion formation considers that attitudes on different issues are usually not independent. In the model, agents exchange beliefs regarding a series of facts. A cognitive structure of evaluative associations links different (partially overlapping) sets of facts on different political issues and determines agents’ attitudinal positions in a way borrowed from expectancy value theory. If agents preferentially interact with other agents who hold similar attitudes on one or several issues, this leads to biased argument pools and increasing polarization in the sense that groups of agents selectively believe in distinct subsets of facts. Besides the emergence of a bi-modal distribution of opinions on single issues as most previous opinion polarization models address, our model also accounts for the alignment of attitudes across several issues along ideological dimensions.