In 1973, the research duo of John Darley and Daniel Batson asked Princeton Theological Seminary students to visit a group of children across campus to deliver a sermon on the parable of the Good Samaritan.
The researchers told some of the future pastors, “It’ll be a few minutes before they’re ready for you, but you might as well head on over.” They told others, “You’re late. They were expecting you a few minutes ago. You’d better get moving.”
While proceeding across campus, each subject passed a man slumped in a doorway, moaning and coughing.
Imagine yourself in this situation: A classroom of children awaits you but, along the way, you encounter a man who’s clearly in distress. Is there any doubt what you do? Or what religiously attuned students would do? No matter the circumstances, we’d expect everyone to help. However, only 10 percent of the “hurried” students stopped to offer assistance.
The best explanation for this behavior is that, amid the anxiety of running late, most of the students experienced a perceptual shift that caused them not to see the man or recognize his distress.
Robert Pearl writing in Vox