Fujimaki Shun, Sakagami Takayuki
Department of Psychology, Keio UniversityTokyo, Japan; Japan Society for the Promotion of ScienceTokyo, Japan.
Department of Psychology, Keio University Tokyo, Japan.
Front Psychol. 2016 Mar 16;7:363. doi: 10.3389/fpsyg.2016.00363. eCollection 2016.
The sunk cost fallacy is one of the irrational choice behaviors robustly observed in humans. This fallacy can be defined as a preference for a higher-cost alternative to a lower-cost one after previous investment in a higher-cost alternative. The present study examined this irrational choice by exposing pigeons to several types of trials with differently illuminated colors. We prepared three types of non-choice trials for experiencing different outcomes after presenting same or different colors as alternatives and three types of choice trials for testing whether pigeons demonstrated irrational choice. In non-choice trials, animals experienced either of the following: (1) no reinforcement after the presentation of an unrelated colored stimulus to the alternatives used in the choice situation, (2) no reinforcement after investment in the lower-cost alternative, or (3) reinforcement or no reinforcement after investment in the higher-cost alternative. In choice trials, animals were required to choose in the following three situations: (A) higher-cost vs. lower-cost alternatives, (B) higher-cost vs. lower-cost ones after some investment in the higher-cost alternative, and (C) higher-cost vs. lower-cost alternatives after the presentation of an unrelated colored stimulus. From the definition of the sunk cost fallacy, we assumed that animals would exhibit this fallacy if they preferred the higher-cost alternative in situation (B) compared with (A) or (C). We made several conditions, each of which comprised various combinations of three types of non-choice trials and tested their preference in three choice trials. Pigeons committed the sunk cost fallacy only in the condition that contained non-choice trials (3), i.e., pigeons experienced reinforcement after investing in the higher-cost alternative. This result suggests that sunk cost fallacy might be caused by the experiences of reinforcement after investing in the higher-cost alternative.
沉没成本谬误是在人类中被广泛观察到的非理性选择行为之一。这种谬误可以被定义为，在先前对成本较高的选项进行投资后，更倾向于选择成本较高的选项而非成本较低的选项。本研究通过让鸽子接触几种不同颜色光照的试验来检验这种非理性选择。我们准备了三种非选择试验，用于在呈现相同或不同颜色作为选项后体验不同的结果，以及三种选择试验，用于测试鸽子是否表现出非理性选择。在非选择试验中，动物经历以下情况之一：(1) 在呈现与选择情境中使用的选项无关的颜色刺激后没有强化；(2) 在对成本较低的选项进行投资后没有强化；(3) 在对成本较高的选项进行投资后有强化或没有强化。在选择试验中，要求动物在以下三种情况下进行选择：(A) 成本较高的选项与成本较低的选项；(B) 在对成本较高的选项进行一定投资后，成本较高的选项与成本较低的选项；(C) 在呈现与选择情境中使用的选项无关的颜色刺激后，成本较高的选项与成本较低的选项。根据沉没成本谬误的定义，我们假设，如果动物在情况 (B) 中比在情况 (A) 或 (C) 中更倾向于选择成本较高的选项，那么它们就会表现出这种谬误。我们设定了几个条件，每个条件都包含三种非选择试验的不同组合，并在三种选择试验中测试它们的偏好。鸽子仅在包含非选择试验 (3) 的条件下出现了沉没成本谬误，即鸽子在对成本较高的选项进行投资后获得了强化。这一结果表明，沉没成本谬误可能是由对成本较高的选项进行投资后获得强化的经历所导致的。
