Employees at HMRC were all given ecards from a current charity donor. In the treatment group, a picture of the donor was included; in the control group, no such picture was included. Researchers found that the control group's donation participation rate was 2.9%, compared to the treatment group's rate of 6.4%. Including a photo the current donor, in short, doubled participation rates.
Biases Used
Bias
Mere Exposure Effect
Further Reading
Other Applications: Eating Behavior, Education, Law Abiding Behavior