Brain region balances competing interests in moral judgments
Deciding whether to kill one person to save five is a true brain teaser. A study in the March 26 Journal of Neuroscience describes the neural tug-of-war that results in a moral decision.
Cognitive neuroscientists Amitai Shenhav of Princeton University and Joshua Greene of Harvard University asked 35 people to weigh in on 48 wrenching scenarios while undergoing functional MRI brain scans. The researchers used scenarios akin to the famous trolley choice: The hypothetical dilemma forces a person to decide whether to push an innocent man to his death to stop a runaway trolley from killing five people.
This type of moral quandary evokes competing motivations: the urge to save the greatest number of people and the desire to avoid emotionally repellent behavior. In their experiment, Shenhav and Greene separated these considerations by asking people to