Not getting enough charitable donations? Try having people to touch sandpaper before you ask for money. A new study shows that touching rough surfaces triggers the emotion of empathy, which motivates people to donate to non-profit organizations. "We found that when people were experiencing mild discomfort as a result of touching a rough surface, they were more aware of discomfort in their immediate environment," said Chen Wang, an assistant marketing professor at Drexel University in Pennsylvania. "They could better empathize with individuals who were suffering."

Their findings are available online in the Journal of Consumer Psychology. In one experiment, the team tested brain activity when participants viewed painful versus neutral images. In some trials the participants held an object wrapped in sandpaper -- known as haptic roughness -- while they saw the pictures. In other trials they held an object wrapped in smooth paper. The participants showed more brain activity when touching the sandpaper than the smooth paper, particularly when viewing the painful images. 

In another experiment the researchers asked one group of participants to wash their hands with a smooth soap and the other with a rough, exfoliating solution. Then each group filled out questionnaires rating their willingness to donate to a charity. The group that had used the rough hand wash was more willing than the soft soap group to donate to a lesser-known foundation that supports people who suffer from Sjogren's Syndrome, an autoimmune disease in which the white blood cells attack the moisture-producing glands. 

This difference between the groups did not occur when participants rated their willingness to give to the well-known National Breast Cancer Foundation. Familiarity with a charity overrode the effect of haptic roughness, Wang said.

The findings could have significant implications for less well-known charities that are trying to raise money, according to the study. 

"Often smaller charities invest a lot of money in advertising to build awareness, but our data suggests that introducing haptic roughness into outreach materials could be an innovative and cost-effective approach," she said.