Many of us are familiar with the trolley problem, a thought experiment introduced by Foot and Thomson (2008) to gauge behavior in a difficult moral situation. In the trolley problem, you are in charge of a lever that can turn the trolley down a different path. Why would you do this? Well, the trolley is currently heading toward five innocent victims who just happen to be in the path of the trolley and unaware of their imminent demise. Why might you not pull the lever? On the alternative path, there is also an innocent victim in the path of the trolley. Do you passively let the trolley run over the five victims, or do you make a decision that leads to the death of one individual?
What happens if the person pulling the lever weren’t you, and what happens if they had the option to “self-kill” – put themselves on the path of the trolley? Marczyk and Marks (2014) examined how participants felt when watching another person make such a decision on the trolley problem. They found that participants deemed it “least permissible” when the actor behind the lever let the trolley hit anyone that wasn’t themselves. The only moral action was to self-kill. Socially, these results imply that self-sacrifice is weighted highly in circumstances where it is an option. Despite this fact, will anyone choose to sacrifice themselves in the trolley problem?
For many people, the utilitarianism approach makes the most sense in the trolley problem. The utilitarianism approach indicates that the more people saved, the better. In Cao et al. (2017), when fifteen people were at risk rather than just five, the vast majority of people pulled the lever. It appears that utilitarianism is likely to be the prevailing approach as the number of victims increases. However, there is a catch. Cao et al. (2017) added to the study the footbridge version of the trolley problem, which is as follows: You are on a bridge with another individual when you see the trolley passing below you toward a group of people. You have the option to push the individual off the bridge into the path of the trolley and their body will stop the trolley – but they will die. In this study, even when the number of victims was fifteen, participants were still very hesitant to push the individual into the path of the trolley.
The footbridge version presents a slightly different dilemma: would you go to the length of directly sending someone to their death to save other people? In the original trolley version, your primary action is diverting the train and killing someone just happens to be a consequence. However, in the footbridge version, your primary action is pushing an individual to their death. Does this change the way you feel about saving the doomed victims on the track?
Nasello et al. (2001) suggested that personal moral decisions are mostly influenced by social-emotional responses whereas impersonal moral decisions are mostly influenced by cognitive processes. They proposed a dual-process morality theory where one system, fast and intuitive, is highly emotional and likely to produce non-utilitarian decisions. In contrast, the other system is slow and elaborative, involves cognitive processes, and is likely to produce utilitarian decisions. Is either system better, or more “moral?” That’s a personal interpretation.
Extrapolating to the general context of moral psychology: sometimes, there are inconsistencies in what one thinks should be done in a moral situation and what one would do if they were in that situation themselves. Gold and Colman (2015) investigated three different hypotheses for why this would be the case. The Akrasia hypothesis posits that there is a difference in how one judges the morality of a possible action and whether they will choose to follow the more moral behavior themselves. This occurs when people choose to act against their overall judgment. The Differing perspective hypothesis suggests that there exists an egocentric perspective and an allocentric perspective to any moral situation. When we are made to be the actor in a situation, it is considered egocentric. Most moral scenarios are allocentric because individuals are asked to judge the morality of certain actions despite not imposing themselves onto the scene. Finally, the Separate processes hypothesis offers a dual process theory of moral judgment which we have discussed in a previous section, where utilitarian and intuitive processes are both involved. The Separate processes hypothesis further suggests that utilitarian responses are more cognitively burdensome and take longer to formulate whereas intuitive responses are almost immediate. Authors found evidence that the Separate processes hypothesis is most likely to guide moral decision making, followed by the Akrasia hypothesis, and lastly, the Differing perspective hypothesis.
There are some limitations to using the trolley problem to study moral psychology. Sacrificial dilemmas are rare in every day life, reducing their external validity. These dilemmas tend to be entertaining rather than the subject of deep ponderance. They also don’t provoke similar psychological processes as other moral situations that may be more entrenched in reality such as a cooperation game, an economic game, or a shock-inducing situation. Bauman et al. (2014) suggest not using sacrificial thought experiments as a means of studying real world moral psychology.
Does any of this research affect what you would do in the trolley problem?
Bauman, McGraw, A. P., Bartels, D. M., & Warren, C. (2014). Revisiting External Validity: Concerns about Trolley Problems and Other Sacrificial Dilemmas in Moral Psychology. Social and Personality Psychology Compass, 8(9), 536–554. https://doi.org/10.1111/spc3.12131
Cao, F., Zhang, J., Song, L., Wang, S., Miao, D., & Peng, J. (2017). Framing effect in the trolley problem and footbridge dilemma: Number of saved lives matters. Psychological reports, 120(1), 88-101.
Gold, Pulford, B. D., & Colman, A. M. (2015). Do as I Say, Don’t Do as I Do: Differences in moral judgments do not translate into differences in decisions in real-life trolley problems. Journal of Economic Psychology, 47, 50–61. https://doi.org/10.1016/j.joep.2015.01.001
Marczyk, J., & Marks, M. J. (2014). Does it matter who pulls the switch? Perceptions of intentions in the trolley dilemma. Evolution and Human Behavior, 35(4), 272-278.
Nasello, Dardenne, B., Blavier, A., & Triffaux, J.-M. (2021). Does empathy predict decision-making in everyday trolley-like problems? Current Psychology (New Brunswick, N.J.). https://doi.org/10.1007/s12144-021-01566-1
Thomson, J. J. (2008). Turning the trolley. Philosophy & Public Affairs, 36(4), 359-374.