Proceedings of the Annual Meeting of the Cognitive Science Society

Measuring and quantifying degrees of belief poses a fundamental challenge, prompting an exploration into how humans navigate uncertainty. This study challenges the conventional use of probability theory and investigates ranking theory as a viable alternative model. Across the initial three experiments (N = 168; N = 63; N = 200), participants consistently utilized negative ranking functions to express disbelief, revealing a robust pattern across diverse contexts. Notably, a logarithmic relationship emerged between subjective probability and negative ranks (degree of disbelief), highlighting the granularity of ranking functions. Experiment 3 introduced positive ranks, illustrating a log-odds relationship between subjective probability and two-sided ranks (degree of disbelief and belief), providing a detailed depiction of the full spectrum of beliefs. In Experiment 4 (N = 201), examining ranks and subjective probability in a learning task revealed that disbelief via negative ranking functions more accurately represented the objective probability distribution than subjective probability. Lastly, Experiment 5 (N = 291) addressed decision-making under uncertainty through the Ellsberg paradox, uncovering how ranking theory not only resolved contradictions with expected utility theory but also eliminated the paradoxical nature of the Ellsberg scenario. This study advances our understanding of human uncertainty and supports ranking theory as a compelling alternative.