Recent research published by Psychological Science from Program on Negotiation faculty member and assistant professor at Harvard University’s Department of Psychology Joshua Greene ^[1] and his colleague Elinor Amit explores the impact vivid mental imagery has on decision-making processes.

While many people believe that their moral compass ^[2] comes from religion, the teachings of their elders, or from community values, Greene and Amit hypothesized that basic morality is a quality inherent to the human brain.

To test their hypothesis, Greene and Amit presented experiment participants with one story with very vivid imagery and another story without such vivid imagery.

One of the story dilemmas Greene cites is that of the trolley:

A trolley is heading towards a group of people. You can flip a switch to save the group, but doing so will divert the trolley onto another track and kill one individual.

The other story dilemma, quite similar to the first but different in key ways, is:

A trolley is crossing a footbridge and a tall backpacker is standing beside you. In order to save the people on the trolley from driving over the edge, you must push the “big guy” into the oncoming trolley and sacrifice him.

In the first instance: The would-be hero only needs to flip a switch.

In the second instance: He must physically sacrifice someone else.

The first story allows for a rational, cost-benefit analysis of the situation – sacrifice the life of one to save the lives of many.

Yet in the second story, when faced with a much more direct form of participation, a moral dilemma is introduced when the participant imagines pushing a person to his death in order to save the lives of others.

Because the first story does not conjure up such vivid imagery, participants were inclined to choose to flip the switch and divert the trolley. But in the second story, there was hesitation because of the proximity of the participant to the hypothetical situation.

Greene and Amit’s research suggests that presenting someone with moral dilemmas evoking vivid mental imagery results in a more emotional judgment. When the participants were distracted and unable to form a vivid mental image in their minds they tended to make more rational decisions.

The impact of mental imagery on a person cannot be ignored ^[3], or as Greene states:

“Emotional responses don’t just pop out of nowhere. They have to be triggered by something. And one possibility is that you hear the words describing some event, you picture that event in your mind, and then you respond emotionally to that picture.”

From NPR: Why Mental Pictures Can Sway Moral Judgment ^[5], by Shankar Vedantam

Related Article: Evenhanded Decision Making ^[6]