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Research Shows Moral Decisions Can Be Manipulated

March 23, 2015

Moral decisions can be influenced by tracking moment-to-moment eye movements during deliberation, according to new research published in the Proceedings of the National Academy of Sciences

The study conducted by UC Merced Professor Michael Spivey and researchers from Lund University in Sweden and University College London challenges the notion that the decisions people make — from whether to give money to a homeless person to whether to separate recyclables from the trash — are rooted in pre-existing moral frameworks.  

“People often assume that their moral opinions are stable preferences that already exist in their hearts and minds,” Spivey said. “But we hypothesized that many of your moral decisions may arise on the fly, as a result of how you look at and interact with your environment.”

Eye trackers monitored study subjects' gaze

Using a novel experimental method, Spivey and his fellow researchers used remote eye trackers to monitor the gazes of participants while they pondered complex moral questions such as, “Is murder sometimes justifiable?” Participants had two possible answers to each question and were asked to consider which of those they considered morally right. 

What the participants didn’t know was that their eye movements were used to determine the points at which they were told to make their decisions. For each trial, one of the possible responses was randomly selected by the researchers. Once each participant’s eye tracker registered that he or she had looked at the target response for a certain amount of time, he or she was asked to make a decision immediately. 

The results showed that participants’ moral decisions were systematically biased toward the targets when eye gaze was used to determine the timing of their responses, meaning they were influenced without the use of differing arguments or information. They choose the randomly selected alternatives as their own moral opinions in 58 percent of the trials, compared to 50 percent when there was no such manipulation.

Timing of decisions can influence choices  

“What we find in this study is that the precise timing of our decisions can be a powerful influence on the choices that we end up making,” Lund Professor Philip Pärnamets said. “The process of arriving at a moral decision is not only reflected in people’s eye gaze, but can also be determined by it.”

The study is the first to demonstrate causal links between gaze and moral choices, but it builds on previous work showing how gaze is reflected in simple choices, such as between different types of food. 

“Scientists already knew that when we look back and forth between two items on a menu, for example, our gaze patterns reveal what we might choose,” Union College London Professor Daniel Richardson said. “Our main contribution is to show that by controlling exactly when someone makes a decision, we can influence what they decide.

“In other words, the same interplay between the brain, the hand and the eye that plays out when we reach for a cup of coffee is also involved in reasoning if something is morally right or wrong.”