We’ve all been there. You’re stumbling home after a few drinks on a Saturday night when a moral philosopher jumps out of a bin and hits you with a sudden hypothetical moral dilemma. 

Usually, you’re ready for such devious assaults, but the drink has addled your judgment and now you find yourself spouting utilitarian answers - which suggests that the best course of action is the one that maximizes good for the majority, usually at the expense of a minority. Satisfied, the philosopher disappears into his refuse refuge, and you stagger home only to regret your answer the next morning. 

This ridiculous example highlights the idea of the “drunk utilitarian”, which suggests that people are more likely to show bias towards utilitarian ethics when drunk. The idea has been particularly strong after a famous 2015 study added weight to it. But is it true?  

Introducing the “drunk utilitarian”

In recent years, the “trolley problem” has become a well-known hypothetical challenge that’s designed to test our moral thinking. 

For those who don’t know it, the trolley problem goes like this: an out-of-control rail cart/train/trolley is hurtling towards a junction in the tracks. If the trolley continues as it is, it will hit and kill five people tied to the track. But you, the unfortunate bystander, can save them by pulling a lever that will send the trolley down the other track. However, there is one person tied to this alternative route who will surely die as a consequence. What do you do?

It's a tricky challenge designed to test our ethical thinking and reasoning. In many instances, the outcome people choose depends on the story that sets out the problem, but at its heart it is a question of whether to cause harm for the perceived greater good – the very essence of utilitarianism.    

But what motivates utilitarian thinking? Is it the outcome of increased deliberate reasoning capacity or does it stem from a decreased aversion to harming others? 

In order to study this, two researchers examined 103 drunk men and women in 2015 and then proposed the “drunk utilitarian” idea. This work has since become quite famous and proposed that participant’s blood alcohol concentrations positively correlated with utilitarian answers to the trolley problem. 

According to the study, this demonstrated that impaired social cognition was actually a predictor for utilitarian responses. However, recent research has challenged these findings. 

Last orders for the drunk utilitarian

According to the authors of the more recent study, there was no correlation between alcohol consumption and utilitarian answers when they tried to replicate the 2015 research.

“We wanted to replicate these results, but we aimed to conduct a laboratory study with a placebo condition on a well-powered sample," study author Mariola Paruzel-Czachura, a postdoc at the University of Pennsylvania and an associate professor at the University of Silesia in Katowice, told PsyPost.

In their work, Paruzel-Czachura and colleagues addressed shortcomings of the previous work on this subject, which included limitations such as low or inconsistent levels of alcohol consumed by participants, no use of a placebo group, small sample sizes, confounds in measuring moral dilemma judgment, and a “generalization to utilitarian judgments writ large based on responses to sacrificial dilemmas”.

“To address these concerns”, the authors write, “this preregistered experiment included a manipulation of blood alcohol levels with comparatively higher doses of alcohol and a placebo condition to disentangle actual effects of alcohol from effects of naive beliefs about effects of alcohol.”

To overcome the problems associated with small sampling, the study tested a “substantially larger” sample group compared to previous studies. Then, to overcome “conceptual limitations in the interpretation of pro-sacrificial judgments in trolley problems”, the researchers used the CNI mathematical model to “disentangle different aspects of moral dilemma judgments” and the Oxford Utilitarian Scale (OUS) to “measure different dimensions of utilitarian psychology.”

The researchers recruited 329 participants, approximately equally divided between men and women aged between 18-52. Participants were then separated into three groups: 106 participants were assigned alcohol; 144 were the placebo control group; and 109 had no alcohol as a control (they were given juice and told it was non-alcoholic).

Those in the placebo trial were given juice but were told it was alcoholic. The beverages had been sprayed with alcohol to give them a smell that would help overcome any doubt. Participants in the alcohol trial were given drinks containing “1.6 grams of alcohol at 40% strength for each 1 [kilogram] of the participant’s body weight”. This alcohol was mixed with the same juice given to the other participant groups.

Upon consuming their drinks, all the participants watched 51 minutes of neutral footage designed to allow them enough time to absorb the alcohol. Their blood alcohol levels were then measured a second time (they had been recorded, along with the participants weight, as they started the study).

Following this, the participants were asked to complete a series of 48 dilemmas from the CNI model and then completed the OUS. They then responded to the trolley problem as well as the footbridge problem – another common hypothetical dilemma where a hurtling train/trolley will kill innocent people on the track, but you, the bystander, can stop it by pushing another person off the bridge, which will cause the train to stop. 

Finally, participants completed a cognitive reflection test (CRT), which was designed to “identify potential effects of alcohol on cognitive reflection and to explore whether effects of alcohol on moral judgments are mediated by differences in cognitive reflection”, the authors explained. 

The results did not show any significant association between alcohol consumption and a preference for utilitarian judgment. This poses a challenge to the “drunk utilitarian” phenomenon and does raise further questions about the influence alcohol has on moral decision-making. 

“There is still a possibility that with different levels of alcohol, moral decisions, and judgments could change. We need more studies to understand if and how alcohol impacts morality,” Paruzel-Czachura told PsyPost.