Table 1_Uncertain choices with asymmetric information: how clear evidence and ambiguity interact?.docx

Real-world decisions often involve partial ambiguity, where the complete picture of potential risks is unclear. In such situations, individuals must make choices by balancing the value of available information against the uncertainty of unknown risks. Our study investigates this challenge by examining how people navigate the trade-off between the favorability of limited evidence and the degree of ambiguity when making decisions under partial ambiguity. Participants (n = 77) engaged in a task where the level of ambiguity (small, medium, and large) and the favorability of the evidence (asymmetrically positive, neutral, and asymmetrically negative) were manipulated in a 3 × 3 design. We measured their attitude of ambiguity in each condition. The key finding reveals a bias in how participants perceived the unknown. They reacted to the unknown differently depending on the initial clues, filling in the missing information in a way that contradicted the evidence. When faced with positive evidence, participants were less tolerant of ambiguity than negative evidence. This means people were more careful when they received good news but less cautious when they received bad news. This bias was particularly pronounced when the ambiguity was low.

现实世界中的决策往往涉及部分歧义（partial ambiguity），即潜在风险的完整全貌尚不清晰。在此类情境中，个体需权衡可用信息的价值与未知风险的不确定性，以此完成决策。本研究围绕这一难题展开探究，通过考察个体在部分歧义情境下进行决策时，如何在有限证据的利好性与歧义程度之间权衡取舍。本研究共纳入77名被试，采用3×3实验设计操控歧义水平（低、中、高）与证据利好性（非对称正向、中性、非对称负向），被试需完成对应实验任务。我们对各实验条件下被试的歧义态度进行了测量。核心研究结果揭示了被试对未知事物的感知偏差：被试会根据初始线索对未知做出差异化反应，并以与现有证据相悖的方式填补缺失信息。当面对正向证据时，被试对歧义的容忍度低于负向证据情境。换言之，个体在接收到利好消息时会更为审慎，而在接收到利空消息时则相对放松警惕。该偏差在歧义程度较低的实验条件下表现得尤为显著。