In 1973, John Darley and Daniel Batson conducted a study at Princeton Theological Seminary that tested what actually determines whether a person stops to help someone in need.

The Setup

Seminary students were given one of two topics to speak on: either the parable of the Good Samaritan or an unrelated topic. Some were told they had plenty of time; others were told they were late. On the way to the speaking location, each student passed a slumped, groaning man in a doorway — an actor simulating distress.

The Results

• Whether the student had just been thinking about the Good Samaritan had almost no effect on helping behavior
• Time pressure was the dominant factor: 63% helped when not in a hurry; only 10% helped when late
• Several students in a hurry literally stepped over the slumped man

What This Means

Moral behavior is far more situationally determined than character-determined. Being in a hurry turned theology students into people who stepped over the suffering — regardless of the moral lessons they were literally just rehearsing.

Reference:

Wikipedia: Good Samaritan Experiment

https://en.wikipedia.org/wiki/Bystander_effect