By Steve Martin, Noah Goldstein, and Robert Cialdini.
At a busy New York City subway station we hired researchers to count the number of commuters who donated to a street musician as they walked past.
After a short time a small change was made to the situation that had an immediate and impressive impact. Just before an approaching (and unsuspecting) commuter reached the musician, another person (who was in on the act) would drip a few coins into the musician’s hat in view of the approaching commuter. The result? An eight-fold increase in the number of commuters who chose to make a donations.
In a series of post-study interviews with commuters who did donate, every one of them failed to attribute their action to the fact that they had just seen someone else give money first. Instead they provided alliterative justifications: “I liked the song he was playing”; “I’m a generous person”; and “I felt sorry for the guy.”