Mandatory and Voluntary Giving Both Activate Brain's Pleasure Centers

Scientists have found that people take pleasure in making both voluntary and mandatory donations to a charity, although the voluntary contributions are more satisfying. [Art courtesy of Ann Awh]

Researchers have found that both voluntary and mandatory donations to a charity activate key parts of the brain's reward system, according to a new study in the 15 June issue of Science.

William Harbaugh, professor of economics at the University of Oregon, Eugene, and colleagues studied the neural activity of volunteers after giving money to a food bank. The volunteers donated in two ways: through an automatic, tax-like transfer and through an additional optional, voluntary donation.

By analyzing the activity in the volunteers' ventral striatum, a key part of the brain's reward system, the researchers found that the volunteers took pleasure in contributing to the food bank by either means, but that their sense of well-being increased more when they donated the money voluntarily.

"To economists, this charitable giving is a puzzle: Money is a good, why are people willing to give it away?" wrote the team. "The fact that mandatory transfers to a charity elicit activity in the reward-related areas suggests that even mandatory taxation can produce satisfaction for taxpayers."

The team hypothesized that just as a voluntary food bank donor sees their money serving a public need, tax payers experience the same satisfaction even though the contribution was mandatory.

The researchers propose that their findings may be useful for determining whether taxation tends to discourage charitable giving, or vice versa.

In addition, the team believes that scientists will have the potential to "determine optimum levels of public goods" in a society by studying its citizens neural responses to varying levels of taxes and voluntary donations.

Kathy Wren and Benjamin Somers

18 June 2007