  We propose an agent-based opinion formation model characterised by a two-fold
novelty. First, we realistically assume that each agent cannot measure the
opinion of its neighbours with infinite resolution and accuracy, and hence it
can only classify the opinion of others as agreeing much more, or more, or
comparably, or less, or much less (than itself) with a given statement. This
leads to a classification-based rule for opinion update. Second, we consider
three complementary agent traits suggested by significant sociological and
psychological research: conformism, radicalism and stubbornness. We rely on
World Values Survey data to show that the proposed model has the potential to
predict the evolution of opinions in real life: the classification-based
approach and complementary agent traits produce rich collective behaviours,
such as polarisation, consensus, and clustering, which can yield predicted
opinions similar to survey results.
