Institute of Psychiatry, Psychology and Neuroscience - Department of Psychology, King's College London, London, UK.
Psychon Bull Rev. 2020 Dec;27(6):1333-1340. doi: 10.3758/s13423-020-01775-y.
It is often assumed that most people are loss averse, placing more weight on losses than commensurate gains; however, some research identifies variability in loss sensitivity that reflects features of the environment. We examined this plasticity in loss sensitivity by manipulating the size and distribution of possible outcomes in a set of mixed gambles, and assessing individual stability in loss sensitivity. In each of two sessions, participants made accept-reject decisions for 64 mixed-outcome gambles. Participants were randomly assigned to conditions defined by the relative range of losses and gains (wider range of losses vs. wider range of gains), and the currency-units at stake ('pennies' vs. 'pounds'). Participants showed modest but non-trivial consistency in their sensitivity to losses; though loss sensitivity also varied substantially with our manipulations. When possible gains had greater range than possible losses, most participants were loss averse; however, when possible losses had the greater range, reverse loss aversion was the norm (i.e., more weight on gains than losses). This is consistent with decision-by-sampling theory, whereby an outcome's rank within a consideration-set determines its value, but can also be explained by the gamble's expected-value rank within the decision-set, or by adapting aspirations to the decision-environment. Loss aversion was also reduced in the second session of decisions when the stakes had been higher in the previous session. This illustrates the influence of prior context on current sensitivity to losses, and suggests a role for idiosyncratic experiences in the development of individual differences in loss sensitivity.
人们通常认为大多数人厌恶损失，对损失的重视程度超过了相应的收益；然而，一些研究发现，损失敏感性存在可变性，反映了环境的特征。我们通过在一组混合赌博中操纵可能结果的大小和分布，并评估个体对损失敏感性的稳定性，来研究这种损失敏感性的可塑性。在两次会议中的每一次，参与者都对 64 个混合结果的赌博做出接受或拒绝的决定。参与者被随机分配到由损失和收益的相对范围（损失范围较宽与收益范围较宽）以及风险货币单位（“美分”与“英镑”）定义的条件中。参与者对损失的敏感性表现出适度但并非微不足道的一致性；尽管损失敏感性也随着我们的操纵而发生了很大变化。当可能的收益范围大于可能的损失范围时，大多数参与者厌恶损失；然而，当可能的损失范围较大时，相反的损失厌恶则是常态（即，对收益的重视程度超过了损失）。这与抽样决策理论一致，即结果在考虑集中的排名决定了其价值，但也可以通过决策集中赌博的预期价值排名或通过调整期望以适应决策环境来解释。在前一个会议中 stakes 较高的情况下，第二次会议中的决策中的损失厌恶也会降低。这说明了先前情境对当前损失敏感性的影响，并表明在损失敏感性的个体差异发展中，个体经历的独特性发挥了作用。
