Could you kill one person to save five?

The famous "trolley problem" thought experiment in ethics got a high-tech makeover recently when researchers recreated the scene, the choices, and the violent, bloody, loud repercussions using a computer simulation, joystick and a head-mounted 3D display.

Researchers at Michigan State University equipped 147 volunteers with the headset, joystick and fingertip sensors to monitor emotional reaction. The volunteers were dropped into a virtual world with a view of two diverging train tracks. One set of tracks led through a ravine with a single person walking along the tracks. The other led to another ravine with five people walking along the tracks.

If the volunteer did nothing the train would follow its course, plowing through and killing the five pedestrians. Or the volunteer could use the joystick to throw a virtual switch, diverting the train to the other track and on a path to kill one person.

The study found that 90.5 percent pulled the switch, resulting in the death of one hiker. Three pulled the switch and then returned it to it's original position. The remaining 11 didn't pull the switch.


The conclusion roughly matches past studies that didn't use virtual reality to more graphically depict the consequences of the choices.

"I think humans have an aversion to harming others that needs to be overridden by something," said Carlos David Navarrete, lead researcher on the project. "By rational thinking we can sometimes override it – by thinking about the people we will save, for example. But for some people, that increase in anxiety may be so overpowering that they don't make the utilitarian choice, the choice for the greater good."

What would you do?

Moral dilemma: Would you kill one person to save five? [MSU]