Each participant receive a charity request letter. Some with statistical information about the victims and some with a specific victim.
We are more empathetic to indentifiable victims than to more anonymous victims and abstract statistics
See the full study here :
Small, D. A., Loewenstein, G., & Slovic, P. (2013). Sympathy and callousness: The impact of deliberative thought on donations to identifiable and statistical victims. In The Feeling of Risk (pp. 51-68). Routledge.