Distributions of observed death tolls govern sensitivity to human fatalities
Distributions of observed death tolls govern sensitivity to human fatalities
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DOI：
10.1073/pnas.0908980106
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发表时间：
2009-12-29
影响因子：
11.1
通讯作者：
Sagara, Namika
中科院分区：
文献类型：
--
作者：
Olivola, Christopher Y.;Sagara, Namika
我们如何应对人道主义危机、流行病和其他涉及人命损失的悲惨事件，在很大程度上取决于我们对其相关死亡人数的感动程度。许多研究表明，人们通常对死亡人数表现出越来越小的敏感性，同样地，在涉及人员损失的风险决策中，人们更倾向于风险(而不是确定)替代方案。然而，这种趋势的原因仍不清楚。在这里，我们表明，人们观察到的与事件相关的死亡人数的分布支配着他们对人类死亡的评估和风险偏好。特别是，我们表明，我们对人类死亡的敏感度下降源于这样一个事实，即这些死亡人数大致是按幂规律分布的。我们进一步表明，通过操纵人们观察到的与死亡相关的事件的分布，我们可以改变他们在涉及死亡的决策中的风险偏好。最后，我们表明，在高死亡率事件更频繁发生的国家，在与死亡相关的决策中寻求风险的倾向较低。我们的结果支持基于记忆抽样和相对判断的震级评估模型。这个模型不同于心理学和经济学中通常遇到的基于效用的方法，因为它不依赖稳定的潜在价值表示来解释估值和选择，也不依赖选择行为来推导价值函数。取而代之的是，关于人类死亡的偏好从抽样事件的分布和评估过程的相对性质中自发地出现。
How we react to humanitarian crises, epidemics, and other tragic events involving the loss of human lives depends largely on the extent to which we are moved by the size of their associated death tolls. Many studies have demonstrated that people generally exhibit a diminishing sensitivity to the number of human fatalities and, equivalently, a preference for risky (vs. sure) alternatives in decisions under risk involving human losses. However, the reason for this tendency remains unknown. Here we show that the distributions of event-related death tolls that people observe govern their evaluations of, and risk preferences concerning, human fatalities. In particular, we show that our diminishing sensitivity to human fatalities follows from the fact that these death tolls are approximately power-law distributed. We further show that, by manipulating the distribution of mortality-related events that people observe, we can alter their risk preferences in decisions involving fatalities. Finally, we show that the tendency to be risk-seeking in mortality-related decisions is lower in countries in which high-mortality events are more frequently observed. Our results support a model of magnitude evaluation based on memory sampling and relative judgment. This model departs from the utility-based approaches typically encountered in psychology and economics in that it does not rely on stable, underlying value representations to explain valuation and choice, or on choice behavior to derive value functions. Instead, preferences concerning human fatalities emerge spontaneously from the distributions of sampled events and the relative nature of the evaluation process.