Morality and the Brain: Do We Need a Reboot?

Illustration by R. Kikuo Johnson

The lurid headlines of the past year—cheating politicos, lying coaches—are enough to make you think morality is a thing of the past.

If you ask Joshua Greene, a leading researcher on morality and the brain, he might say the tools most of us use to navigate moral conflicts are outdated, too.

Greene, 37, is a professor at Harvard and a leader in the field of moral psychology. He has been pursuing this line of study since college, when research first began to show that the brain operates fundamentally in two modes. One is automatic and emotional—in essence, a gut reaction. The other is slower, more reasoned. Today, this “dual-process theory” has become the dominant view of the brain.

Greene’s work focuses on what this theory implies about moral decision making. In a series of experiments, some using evidence from brain scans, others focused on external behavior, Greene has found that most of the time, when we’re deciding what is the right thing to do, what’s happening in the brain is the emotional response, not the reasoned one.

In one recent study, for instance, Greene put a new spin on a classic moral dilemma. He asked participants to imagine they were standing on a bridge, beside a large man, overlooking a train track. A runaway trolley is approaching, and it will strike and kill five people. Is it moral to push the large man onto the track, knowing that he’ll be hit and killed by the trolley, but that the five people will be spared? Most participants said no. It’s immoral.

However, when the scenario was rephrased—is it moral to press a switch to open a trap door beneath the man’s feet?—most participants said yes, that would be the right thing to do.

Outside of academia, it’s not about trolleys and bridges. Instead, Greene points to such morally fraught issues as stem-cell research and physician-assisted suicide, which provoke different emotions in people and will never be resolved without the most impartial analysis.

Ultimately, this is Greene’s great quest: to help people understand that moral progress only becomes possible when we don’t believe everything we immediately think.