Proceedings of the Annual Meeting of the Cognitive Science Society

This study aimed to explore whether the risk-reward correlation would hold in verbal probability phrases. The risk-reward correlation refers to a tendency to infer inverse proportionality between probability and outcome magnitude and have been considered as reflecting the statistical structure of the environment. Existing studies have demonstrated this inverse proportionality in numerical probabilities. However, it is well known that verbal probability phrases can convey contextual information about uncertainty without numbers, and express contextual information that are not contained by numerical probabilities. Specifically, verbal probabilities have positive and negative directionality that make listener’s attention to occurrence or non-occurrence of outcome and as a result affect listener’s decision making. A purpose of this study is to examine whether the risk-reward correlation also hold in verbal probability phrases, To accomplish this, two empirical studies that required participants to estimate reward values and winning probability of gambles that were expressed by verbal probability phrases such as “certain” or “impossible” were performed. Results indicate that risk-reward correlation also hold in verbal probability phrases, and the directionality of the verbal probability phrases.