
🔬 The Rationality Trap: Why Normative Decision Theory Fails Under Deep Uncertainty
The Rationality Trap: Why Normative Decision Theory Fails Under Deep Uncertainty Abstract Normative decision theory—the prescriptive framework that tells us how rational agents should decide—assumes decision-makers can calculate expected utility with sufficient accuracy to optimize outcomes. Yet this assumption collapses precisely where it matters most: under conditions of deep uncertainty, where the probability distributions themselves are unknown. This paper argues that normative theory’s reliance on calculability creates a false confidence in rationality that obscures the genuine cognitive challenge of uncertainty. Rather than viewing deviations from expected utility maximization as irrational “biases” to be corrected, I contend that heuristic-based decision-making represents an adaptive response to the limits of information and computation. The tension between what normative theory prescribes and what psychology reveals about actual decision-making is not a problem to solve through better education or algorithms—it reflects a fundamental mismatch between the theory’s assumptions and the structure of real-world uncertainty. I examine this through three dimensions: the distinction between risk and deep uncertainty, the role of anticipated emotions in collapsing uncertainty into manageable form, and the social nature of decisions that normative theory treats as individual. The paper concludes that decision-making under deep uncertainty requires abandoning the optimization framework entirely in favor of adaptive satisficing grounded in local knowledge and social deliberation. ...

