Moral decisions can be influenced by tracking moment-to-moment movements of the eyes during deliberation, according to new research published today in the Proceedings of the National Academy of Sciences.
The study, conducted by researchers from the University of California, Merced, 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 a pre-existing moral framework.
“People often assume that their moral opinions are stable preferences that already exist in their hearts and minds,” UC Merced professor Michael 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.”
Using a novel experimental method, Spivey and his fellow researchers used remote eye trackers to monitor the gaze of participants while they pondered complex moral questions, such as, “Is murder sometimes justifiable?” The participants were presented with two alternatives to each question and were asked to consider which of those they considered to be morally right.
What the participants didn’t know was that their eye movements were being used to determine the point at which they were told to make their decision. For each trial, one of the possible responses was randomly selected by the researchers. Once the participant’s eye tracker registered he or she had looked at the target response for a certain amount of time, they were asked to make their decision immediately.
The results showed that the participants’ moral decisions were systematically biased toward the target when eye gaze was used to determine the timing of their response, meaning they were influenced without the use of differing arguments or information. They choose the randomly selected alternative as their own moral opinion in 58 percent of the trials, compared to 50 percent when there was no such manipulation.
“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,” said Lund professor Philip Pärnamets. “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 and gaze and moral choices, but it builds on previous work showing how gaze is reflected in simple choices, like 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.”