Department of Psychology, The Ohio State University, Columbus, OH 43210.
Anderson School of Management, University of California, Los Angeles, CA 90095.
Proc Natl Acad Sci U S A. 2022 Feb 8;119(6). doi: 10.1073/pnas.2101508119.
It is a widely held belief that people's choices are less sensitive to changes in value as value increases. For example, the subjective difference between $11 and $12 is believed to be smaller than between $1 and $2. This idea is consistent with applications of the Weber-Fechner Law and divisive normalization to value-based choice and with psychological interpretations of diminishing marginal utility. According to random utility theory in economics, smaller subjective differences predict less accurate choices. Meanwhile, in the context of sequential sampling models in psychology, smaller subjective differences also predict longer response times. Based on these models, we would predict decisions between high-value options to be slower and less accurate. In contrast, some have argued on normative grounds that choices between high-value options should be made with less caution, leading to faster and less accurate choices. Here, we model the dynamics of the choice process across three different choice domains, accounting for both discriminability and response caution. Contrary to predictions, we mostly observe faster and more accurate decisions (i.e., higher drift rates) between high-value options. We also observe that when participants are alerted about incoming high-value decisions, they exert more caution and not less. We rule out several explanations for these results, using tasks with both subjective and objective values. These results cast doubt on the notion that increasing value reduces discriminability.
人们普遍认为，随着价值的增加，人们对价值变化的选择敏感度降低。例如，人们认为 11 美元和 12 美元之间的主观差异比 1 美元和 2 美元之间的主观差异要小。这个观点与韦伯-费希纳定律和除法归一化在基于价值的选择中的应用以及边际效用递减的心理解释是一致的。根据经济学中的随机效用理论，较小的主观差异预测选择的准确性较低。同时，在心理学中的序列抽样模型中，较小的主观差异也预测响应时间更长。基于这些模型，我们预计高价值选项之间的决策会更慢且准确性更低。相比之下，一些人从规范的角度认为，高价值选项之间的选择应该更加谨慎，从而导致更快但准确性更低的选择。在这里，我们在三个不同的选择领域中建模了选择过程的动态，同时考虑了可辨别性和响应谨慎性。与预测相反，我们在高价值选项之间观察到更多的快速和准确决策（即更高的漂移率）。我们还观察到，当参与者意识到即将做出高价值决策时，他们会更加谨慎，而不是不谨慎。我们使用具有主观和客观价值的任务排除了对这些结果的几种解释。这些结果对增加价值会降低可辨别性的观点提出了质疑。
