Emotion and Reasoning: Competing Forces in Moral Judgment

Yi Zhang, Ph.D.

Philosophers have long been interested in how and why people make judgments in moral dilemmas. Imagine the following scenario (let’s call it the “switch scenario”): a trolley is heading down the tracks toward five people. The only way to save those five lives is to hit a switch that diverts the track down a different track which will kill one person. During this scenario, most people would agree that it’s morally OK to kill the one person to save five others. This is referred to as a utilitarian judgment.

Illustration courtesy of Dr. Greene’s personal website.

Now imagine a slightly different scenario (the “footbridge scenario”), an individual is facing the same problem, but this time, instead of operating a switch, he has to push a big man standing on the footbridge to block the coming train. It’s the same tradeoff of one life versus five lives, but this time, only one third of people would agree that it’s morally OK to push one man to save five men. This begs the question of what makes it morally so wrong to kill the one man in the second scenario.

Illustration courtesy of Dr. Greene’s personal website.

Joshua Greene from Harvard University has a theory for this kind of moral decision making, which he presented in a talk titled “Integrative Moral Cognition” at the 23rd annual convention of the Association of Psychological Science. Dr. Greene argues that, like any other decision making, moral decision making involves two competing neural systems: the automatic affective system and the controlled reasoning system.

This dual-process view is in essence no different from the dual-process models proposed for appetitive behaviors, social stereotypes, or economic decision making , mainly because human beings are always wrestling with the competing forces of our emotions and rational thoughts.

So Dr. Greene set out to test how emotion and reasoning are integrated in the brain during these moral judgments. Using the same footbridge scenario, he asked participants either to consider which action would produce better results (promoting participants to be more utilitarian oriented), which action would make them feel worse (emphasizing the emotional aspect), or simply to take an “all things considered approach.”

The “All Things Considered” Approach

fMRI results showed that when people were prompted to be more utilitarian, their dorsal lateral prefrontal cortex, an area predominantly involved in reasoning and executive control, showed greater activation. When people were prompted to focus on the emotional aspect of moral decisions, their amygdala, a key area involved in attention and emotion, was highly activated.

Finally, when comparing the “all things considered” condition with the other two conditions, there was an increase in the activity in ventral medial prefrontal cortex, which has been inferred to be an area that integrates emotion and reasoning aspects of decision making. Interestingly, a direct comparison between non-utilitarian (those who said it’s not OK to kill) and utilitarian (those who said it’s OK to kill) during the “all things considered” condition indicated relative greater amygdala activation. It seems as if the amygdala is acting like an emotional alarm bell (yelling at the prefrontal cortex that this is NOT OK), whereas it is the ventral medial prefrontal cortex where the relative weights of emotion and utility are being compared and integrated.

Utilitarian Judgments vs. Emotional Judgments

From an applied perspective, there are many ways that can make people more utilitarian oriented. Involving them in a Cognitive Reflection Test (CRT) which requires deep thinking and counter-intuitive judgment is one way to make people more likely to say it is OK to kill one life to save five. People who are more verbally oriented as compared to visually oriented, as assessed by a visual or word working memory test, are also more likely to be utilitarian (the mental imagery of killing the person standing close by may be way too emotional and vivid for visually oriented people).

Public health professional are more likely to be utilitarian than medical doctors in similar dilemmas in the medical setting, probably because they are either trained or self-selected to consider the greater benefit of the majority of the people. Lastly, both Buddhist monks and psychopaths tend to make utilitarian decisions in these moral dilemmas. These are groups of people who either have excellent executive control over their emotional response (the monks), or who don’t have the emotional harness to stop them from doing wrongs (cold-blood killers).

Cognitive neuroscience has made big strides in understanding the role of emotion in decision making in the last decade. Many of the psychological processes that were previously believed to be predominantly cognitive have been found to engage the emotional system. The paradigms used in moral cognition provide a wonderful platform where emotion and reasoning collides, and thus allow scientists to systematically compare the relative forces of the two systems. The advance in our knowledge about these two competing forces has profound implications for market research professionals. Traditionally, consumer choice models have involved a tradeoff between utility and cost.

Moral Judgments in Product Choices

Both our own research and the studies on moral judgment suggest that typical consumers may be faced with a similar tradeoff between emotion and utility in product choices, as they do in moral dilemmas. For example, when deciding on a luxury item, one’s rational choice may be to avoid overspending, yet the appeal of the luxury item acts as an emotional trigger to override rational decision, especially for people who have relatively weaker executive control and a less active dorsal lateral prefrontal cortex. When the luxury item elicits more guilt than pleasure, the resulting negative emotion will likely to act as emotional harness to keep one within rational realm.

To account for the impact of emotional response on consumer decision making, the innovative research at Sentient Decision Science is built on a proportion of emotion model (Reid & Gonzalez-Vallejo, 2009) to predict consumer choices. The proportion of emotion model uses a weighted proportional difference model which treats emotion as a quantifiable measure, and is proven to be more predictive than purely cognitive model in explaining consumer preference (Reid & Gonzalez-Vallejo, 2009). To learn more about how Sentient incorporates emotion and reasoning to more accurately describe consumer choice, contact us at info@sentientdecisionscience.com or visit our website: www.sentientdecisionscience.com



Reid, A.A. & Gonzalez-Vallejo, C. (2009) Emotion as a tradeable quantity. Journal of Behavioral Decision Making, 22, 62-90.

Link to Dr. Greene’s Moral Cognition lab



  • Dear Dr. Zhang, I´m a very senior (70) Spanish consultant and writer. Last week I directed what probably was the first in this country Summer Business School with the theme “Managaement and The Brain”. I´d gladly send you the programe if you send me your email. With my best wishes, Carlos

  • hivesallergy says:

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