Department of Psychology, Harvard University, Cambridge, MA, United States of America.
Center on Long-Term Risk, London, United Kingdom.
Cognition. 2022 Jan;218:104941. doi: 10.1016/j.cognition.2021.104941. Epub 2021 Nov 5.
Is humanity's existence worthwhile? If so, where should the human species be headed in the future? In part, the answers to these questions require us to morally evaluate the (potential) human population in terms of its size and aggregate welfare. This assessment lies at the heart of population ethics. Our investigation across nine experiments (N = 5776) aimed to answer three questions about how people aggregate welfare across individuals: (1) Do they weigh happiness and suffering symmetrically?; (2) Do they focus more on the average or total welfare of a given population?; and (3) Do they account only for currently existing lives, or also lives that could yet exist? We found that, first, participants believed that more happy than unhappy people were needed in order for the whole population to be net positive (Studies 1a-c). Second, participants had a preference both for populations with greater total welfare and populations with greater average welfare (Study 3a-d). Their focus on average welfare even led them (remarkably) to judge it preferable to add new suffering people to an already miserable world, as long as this increased average welfare. But, when prompted to reflect, participants' preference for the population with the better total welfare became stronger. Third, participants did not consider the creation of new people as morally neutral. Instead, they viewed it as good to create new happy people and as bad to create new unhappy people (Studies 2a-b). Our findings have implications for moral psychology, philosophy and global priority setting.
人类的存在有价值吗？如果有，人类在未来应该朝哪个方向发展？在某种程度上，这些问题的答案要求我们根据人口的规模和总体福利来对（潜在的）人口进行道德评估。这种评估是人口伦理的核心。我们通过九个实验（N=5776）的调查，旨在回答三个关于人们如何在个体之间汇总福利的问题：（1）他们是否对称地权衡幸福和痛苦？（2）他们更关注特定人群的平均福利还是总福利？（3）他们是否只考虑当前存在的生命，还是也考虑可能存在的生命？我们发现，首先，参与者认为，为了使整个人口呈净正（研究 1a-c），需要有更多的幸福的人而不是不幸福的人。其次，参与者既偏好总福利更大的人群，也偏好平均福利更大的人群（研究 3a-d）。他们对平均福利的关注甚至导致他们（令人惊讶地）认为，只要增加平均福利，将新的受苦者加入已经悲惨的世界也是可取的。但是，当被提示反思时，参与者对总福利更好的人群的偏好变得更强。第三，参与者并没有将创造新生命视为道德中立。相反，他们认为创造新的幸福的人是好的，而创造新的不幸福的人是坏的（研究 2a-b）。我们的发现对道德心理学、哲学和全球优先事项设定具有影响。
