Marini Marco, Paglieri Fabio
Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche, Roma, Italy.
Istituto di Scienze e Tecnologie della Cognizione, Consiglio Nazionale delle Ricerche, Roma, Italy.
Behav Processes. 2019 May;162:130-141. doi: 10.1016/j.beproc.2019.03.002. Epub 2019 Mar 5.
A decoy is an irrelevant option that, when added to a binary choice, is not selected but nonetheless alters the subjects' preferences, systematically biasing towards its target. The decoy effect, also known as attraction effect, is considered an anomaly of rational decision-making, albeit its applicability to real-life choices outside of laboratory settings has been challenged. In particular, when decoys have been studied in choices between outcomes occurring at different points in time, i.e. intertemporal choices, or with different probabilities of realizing their utility, i.e. probabilistic choices, results were mixed: sometimes decoys are impactful, sometimes they are not, and they seem to be more effective in biasing towards, respectively, larger-and-later and larger-and-riskier outcomes, rather than towards sooner-and-smaller or sooner-and-safer rewards. We suggest that this puzzling set of results can be clarified by focusing on two important influencing factors: time pressure and immediacy/certainty. Moreover, we argue that decoy effects constitute an excellent testbed to assess similarities and differences between intertemporal choice and risky decision-making, which constitutes another open issue in the study of human choice. Two studies are presented to support these claims. In Study 1 (N = 92), we demonstrate that asymmetrically dominated decoys influence both intertemporal choice and risky decision-making only in the absence of time pressure, since otherwise the comparative process required for the decoy to have an impact cannot occur, consistently with predictions made by connectionist models of decision. In Study 2 (N = 53), we show that, when the smaller option is no longer presented as immediate/certain (but rather as sooner/safer), the impact of decoys becomes symmetrical - that is, they can prompt subjects to become either more future-oriented/risk-prone or more present-oriented/risk-averse. We conclude by discussing the implications of these findings for our understanding of the multifaceted role of time and chance in decision making.
诱饵是一个无关选项，当它被添加到二选一的选择中时，不会被选中，但却会改变受试者的偏好，使其系统地偏向目标选项。诱饵效应，也被称为吸引力效应，被认为是理性决策的一种异常现象，尽管其在实验室环境之外的现实生活选择中的适用性受到了挑战。特别是，当在不同时间点出现的结果之间的选择中研究诱饵时，即跨期选择，或者在实现其效用的不同概率的选择中研究诱饵时，即概率选择，结果参差不齐：有时诱饵有影响，有时则没有，而且它们似乎分别在偏向更大且更晚出现的结果和更大且风险更高的结果方面更有效，而不是偏向更早且更小或更早且更安全的奖励。我们认为，通过关注两个重要的影响因素：时间压力和即时性/确定性，可以澄清这一系列令人困惑的结果。此外，我们认为诱饵效应构成了一个极好的试验台，用于评估跨期选择和风险决策之间的异同，这是人类选择研究中的另一个未解决问题。本文呈现了两项研究来支持这些观点。在研究1（N = 92）中，我们证明不对称占优诱饵仅在没有时间压力的情况下影响跨期选择和风险决策，因为否则诱饵产生影响所需的比较过程无法发生，这与决策的联结主义模型所做的预测一致。在研究2（N = 53）中，我们表明，当较小的选项不再被呈现为即时/确定（而是更早/更安全）时，诱饵的影响变得对称——也就是说，它们可以促使受试者变得要么更面向未来/倾向于冒险，要么更关注当下/规避风险。我们通过讨论这些发现对我们理解时间和机会在决策中的多方面作用的影响来得出结论。
