Emotion and Cognition in Moral Judgment

Princeton University, Princeton NJ

Investigators

Abstract

Drs. Cohen, Darley, and Greene's research funded by NSF on neuroscientific moral psychology was inspired by a puzzling set of moral dilemmas posed by philosophers. Consider the following case: A runaway trolley is headed for five people who will be killed if it proceeds on its present course. The only way to save them is to flip a switch that will turn the trolley onto an alternate set of tracks where it will kill one person instead of five. Ought you to turn the trolley in order to save five people at the expense of one? Most people say yes. Now consider a similar dilemma: As before, a trolley threatens to kill five people. You are standing next to a large stranger on a footbridge spanning the tracks, in between the oncoming trolley and the five people. This time, the only way to save the five people is to push this stranger off the bridge and onto the tracks below. He will die if you do this, but his body will stop the trolley from reaching the others. Ought you to save the five others by pushing this stranger to his death? Most people say no. For over twenty years, moral philosophers have been puzzling over cases such as these, wondering what makes it acceptable to sacrifice lives in some cases but not others. In their research, Drs. Cohen, Darley, and Greene attack these problems from the point of view of social psychology and cognitive neuroscience: What goes on in people's brains that makes them say "yes" to the first case and "no" to the second case? Existing theories of moral psychology suggest strikingly different answers to this question. According to the rationalist tradition in moral psychology, moral judgments are caused by episodes of reasoning and reflection. More specifically, a rationalist would say that people arrive at different answers in these two cases by applying abstract moral principles that explain why these cases are importantly different. A more recent trend in moral psychology places increased emphasis on emotion. According to an emotivist model, differences in emotional response are to explain people's divergent answers in these two cases. Drs. Cohen, Darley, and Greene believe that rationalists and emotivists are both partly correct. Their NSF-supported research is aimed at understanding how emotional and "cognitive" processes interact to produce moral judgments. Their research uses both traditional methods such as questionnaires and measurements of reaction time in conjunction with cutting-edge neuroimaging techniques that allow them to see what is going on in people's brains while they make moral decisions. This research has natural connections to matters of both private and public concern. First, understanding the psychological and biological bases of human morality is of fundamental humanistic importance. Like research concerning the origins of life on Earth or the large-scale structure of the universe, this research addresses questions that are of intrinsic interest to people around the world. Our capacity for moral judgment is central to our humanity, and yet it is not well understood by science at this time. This research is an important step toward remedying this ignorance. Second, moral judgment is of immense practical importance. Many of the great public debates of our time such as those concerning abortion, stem cell research, the limits of justifiable war, the appropriate response to terrorism, etc. exist because different people have different intuitions about these and other matters of right and wrong. To make progress on these issues it may be useful, if not essential, to understand the psychology and underlying biology that produces moral judgments, and different moral judgments in different people. One of the goals of this research is to study culturally-based differences in moral judgment, which has the additional benefit of ensuring the participation of groups who are underrepresented in American science. This research will also explore differences in moral judgment based on gender and individual temperament. At the same time, however, this research is aimed at understanding that which is universal in human moral judgment.