My friend, Kim Ervin, turned me on to this great NPR story, Why Your Brain Wants To Help One Child In Need — But Not Millions, by Shankar Vedantam. Please give it a listen.

A story about an individual victim affects us emotionally. But a million people in need speaks to our head, not our heart. "As the numbers grow," [Psychologist Paul Slovic of the University of Oregon] explains, "we sort of lose the emotional connection to the people who are in need."

Vedantam talks about the desire to help one little girl is "contaminated" by knowing all the people the donor is not helping. Donors are "de-motivated" by feeling ineffective or hopeless so they give less.Your donor believes she can make a small change and help one person. But making a huge change, like ending homelessness or domestic violence, doesn't feel possible. It feels too big to tackle and they give less. Consider the implications of scale for your storytelling. Keep the story on the small scale, a human helping another human instead of "our organization helping the community achieve system change."