Stickler Megan, Ott William, Kilpatrick Zachary P, Josić Krešimir, Karamched Bhargav R
Department of Mathematics, University of Houston, Houston, Texas 77004, USA.
Department of Applied Mathematics, University of Colorado Boulder, Boulder, Colorado 80309, USA.
Phys Rev Res. 2023 Sep;5(3). doi: 10.1103/physrevresearch.5.033020. Epub 2023 Jul 10.
Normative models are often used to describe how humans and animals make decisions. These models treat deliberation as the accumulation of uncertain evidence that terminates with a commitment to a choice. When extended to social groups, such models often assume that individuals make independent observations. However, individuals typically gather evidence from common sources, and their observations are rarely independent. Here we ask: For a group of ideal observers who do not exchange information, what is the impact of correlated evidence on decision accuracy? We show that even when agents are identical, correlated evidence causes decision accuracy to depend on temporal decision order. The first decider is less accurate than a lone observer, and early deciders are less accurate than late deciders. These phenomena occur despite the fact that the rational observers use the same decision criterion, so they are equally confident in their decisions. We analyze discrete and macroscopic evidence-gathering models to explain why the first decider is less accurate than a lone observer when evidence is correlated. Pooling the decisions of early deciders using a majority rule does not rescue accuracy results in only a modest accuracy gain. Although we analyze an idealized model, we believe that our analysis offers insights that do not depend on exactly how groups integrate evidence and form decisions.
规范性模型常被用于描述人类和动物如何做出决策。这些模型将决策过程视为不确定证据的积累，最终做出选择。当扩展到社会群体时，此类模型通常假定个体进行独立观察。然而，个体通常从共同来源收集证据，且他们的观察很少是独立的。在此我们提出问题：对于一组不交换信息的理想观察者而言，相关证据对决策准确性有何影响？我们表明，即便主体完全相同，相关证据也会使决策准确性取决于时间决策顺序。第一个做出决策的人比单独的观察者准确性更低，且较早做出决策的人比晚些做出决策的人准确性更低。尽管理性观察者使用相同的决策标准，因而他们对自己的决策同样有信心，但这些现象依然会出现。我们分析离散和宏观证据收集模型，以解释为何在证据相关时，第一个做出决策的人比单独的观察者准确性更低。使用多数规则汇总较早做出决策者的决策并不能挽救准确性，只会带来适度的准确性提升。尽管我们分析的是一个理想化模型，但我们认为我们的分析提供了一些见解，这些见解并不依赖于群体究竟如何整合证据并做出决策。
