In a new paper, David Althaus, Andreas Mogensen, Geoffrey Goodwin, and I, investigate people's population ethical intuitions. Across nine experiments (N = 5,776), we studied how lay people judge the moral value of hypothetical human populations that differ in their size and in the quality of the individual lives that comprise them. Our investigation aimed to answer three questions:
- Do people weigh happiness and suffering symmetrically?
- Do people focus more on the average or total welfare of a given population?
- Do people account only for currently existing lives, or also lives that could yet exist?
Here is a very brief summary of the key findings (more details can be found in the linked paper):
1. People, on average, weigh suffering more than happiness
Participants, on average, believed that more happy than unhappy people were needed in order for the whole population to be net positive (Studies 1a-c). Judgments about the acceptable proportion of happy and unhappy people in a population matched judgments about the acceptable proportion of happiness and unhappiness within a single individual’s lifetime. The precise trade ratio between happiness and suffering depended on the intensity levels of happiness and suffering, such that a greater proportion of happiness was required as intensity levels increased (Study 1b). Study 1c clarified that, on average, participants continued to believe that more happiness than suffering was required even when the happiness and suffering units were exactly equally intense. This suggests that people generally weigh suffering more than happiness in their moral assessments, above and beyond perceiving suffering to be more intense than happiness. However, our studies also made clear that there are individual differences and that a substantial proportion of participants weighed happiness and suffering equally strongly, in line with classical utilitarianism.
2. People have both an averagist and a totalist preference
Participants had a preference both for populations with greater total and greater average welfare (Study 3a-d). In Study 3a, we found that participants preferred populations with better total levels (i.e., higher levels in the case of happiness and lower levels in the case of suffering) when the average levels were held constant. In Study 3b, we found that participants preferred populations with better average levels when the total levels were held constant. In Study 3c, we found that most participants’ preferences lay in between the recommendations of these two principles when they conflict, suggesting that participants applied both preferences simultaneously in such cases. Further, 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 (Study 3d). But, when prompted to reflect, participants’ preference for the population with the better total welfare became stronger.
3. People value the addition of new people
Participants viewed it as good to create new happy people and as bad to create new unhappy people (Studies 2a-b). This means that people do not endorse the so-called intuition of neutrality according to which creating new people with lives worth living is morally neutral. Moreover, we also found that people’s judgments about the positive value of adding a new happy person and the negative value of adding a new unhappy person were roughly symmetrical. That is, their judgments did not reflect the so-called asymmetry—according to which adding a new unhappy person is bad but adding a new happy person is neutral. It is surprising that people’s judgments about adding a new happy or unhappy person were symmetrical given that they weighed suffering more than happiness when asked about the appropriate proportion of happy vs. unhappy people in a population in Studies 1a-c (and we discuss possible explanations in the paper).
To our knowledge, this is the first empirical investigation of people's population ethical intuitions in the academic psychological literature (see Dean Spears' related research (1, 2) in economics). We hope this paper could trigger more psychological research in this domain.