Key Insight
Kahan argues that 'bounded rationality' is an unkillable but misleading explanation for public disagreement over science — and why cultural cognition provides a better account.
The bounded rationality explanation for public disagreement goes roughly like this: ordinary citizens lack the cognitive resources to properly evaluate complex empirical evidence. As a result, they rely on heuristics that lead them systematically astray.
Cultural Cognition Project studies consistently find that higher science literacy and numeracy are associated with greater polarization on culturally contested risk issues — not less. If bounded rationality were the culprit, we would expect the opposite.
Bounded rationality survives repeated empirical challenges because it is partially correct — ordinary citizens do use heuristics. But it misidentifies the mechanism producing cultural polarization specifically. The problem is not that people lack the reasoning capacity to evaluate evidence correctly. The problem is that they deploy their reasoning in the service of identity-protective goals.