When people perceive money as morally tainted, they also view it as having less value and purchasing power, according to a new study.
Researchers from the University of California, Berkeley and Stanford University found evidence that source of wealth really does matter to people.
The study challenges the belief that "all money is green," and that people will cross ethical boundaries to amass it.
In fact, the study found that some people avoid ill-gotten gains - such as profits from unfair labour practices or insider trading - for fear of "moral contagion".
"Our work suggests morality is an important force shaping economic decision-making," said Jennifer Stellar, a doctoral student in psychology and lead author of the study.
"Though we often think USD 50 is USD 50, these results demonstrate that when money takes on negative moral associations, its value is diminished," Stellar said.
The findings shed some light on why companies go to great lengths to avoid the perception that they are accepting money from corrupt investors or are themselves profiting from illegal or unethical practices, researchers said.
"People possess powerful motivations to view themselves as fundamentally good and moral," said Robb Willer, associate professor of sociology at Stanford University and co-author of the paper.
"We find this motivation is so great that it can even lead people to disassociate themselves from money that has acquired negative moral associations," Willer said.
The study found individuals believe that acquiring morally tainted money threatens their own moral character.
But by removing those fears and making participants feel certain in their moral high ground, the researchers were able to diminish the threat of accepting morally tainted money, Willer said.
"Money is often believed to separate individuals from their moral values," Willer said.
"However, our results suggest that, for most people, morality is a powerful force that shapes economic decisions and even alters how we perceive the value of money itself," Willer added.
