Is it better to save 4500 lives out of 11,000 or 4500 lives out of 250,000? Fetherstonhaugh et al. (1997) showed that people prefer the former: to save lives if they are a higher proportion of the total, a phenomenon they termed “psychophysical numbing”. We attempted to replicate Studies 1 and 2 of Fetherstonhaugh et al. (1997) (5 data collections, total N = 4799, MTurk and Prolific, USA and UK), and added several extensions (e.g., donation amounts, procedural differences, and individual-level ideology and knowledge). We found mixed support, with two successful replications of Study 2 that indeed showed psychophysical numbing (original: η²_p = 0.55, 90% CI [0.45, 0.62], Study 2a: η²_p = 0.62, 90% CI [0.58, 0.66], Study 2b: η²_p = 0.24, 90% CI [0.21, 0.27], all in same direction), yet also three unsuccessful replications of Study 1 showing instead an opposite psychophysical sensitization, a preference for saving a smaller proportion of lives (original effect size: η²_p = 0.14, 90% CI [0.02, 0.28], replications: Study 1a: η²_p = 0.06, 90% CI [0.02, 0.10], Study 1b: η²_p = 0.21, 90% CI [0.17, 0.26]; Study 1c: η²_p = 0.13, 90% CI [0.08, 0.17], all in the opposite direction). We discuss theoretical implications and potential drivers of psychophysical numbing and sensitization, including evaluation mode, comparison procedure, ideology, knowledge, and prioritizing of one's own country, and practical implications for research on perceptions of charity, aid effectiveness, and donations. Materials, preregistrations, data, and analyses are available at https://osf.io/786jg/.

挽救 11,000 人中的 4500 条生命还是挽救 250,000 条生命中的 4500 条生命更好？费瑟斯顿豪等人。(1997) 表明人们更喜欢前者：如果他们在总数中的比例较高，则可以挽救生命，他们将这种现象称为“心理物理麻木”。我们试图复制 Fetherstonhaugh 等人的研究 1 和 2。(1997)（5 个数据集，总N  = 4799，MTurk 和 Prolific，美国和英国），并添加了一些扩展（例如，捐赠金额、程序差异和个人层面的意识形态和知识）。我们发现了不同的支持，研究 2 的两次成功复制确实显示出心理生理麻木（原始：η ² _p  = 0.55，90% CI [0.45, 0.62]，研究 2a：η ² _p  = 0.62，90% CI [0.58， 0.66]，研究 2b：η² _p  = 0.24, 90% CI [0.21, 0.27]，都在同一个方向），但研究 1 的三个不成功的重复显示相反的心理物理敏感性，倾向于挽救较小比例的生命（原始效应大小：η ² _p  = 0.14, 90% CI [0.02, 0.28]，重复：研究 1a：η ² _p  = 0.06，90% CI [0.02, 0.10]，研究 1b：η ² _p  = 0.21，90% CI [0.167, 0. ]；研究 1c：η ² _p = 0.13, 90% CI [0.08, 0.17]，都在相反的方向）。我们讨论了心理物理麻木和敏感的理论意义和潜在驱动因素，包括评估模式、比较程序、意识形态、知识和本国的优先次序，以及对慈善观念、援助有效性和捐赠的研究的实际意义。材料、预注册、数据和分析可在 https://osf.io/786jg/ 获得。