As the researchers published in the journal Psychological Science, most people are unaware of how their emotions at the time of a purchase can influence their decisions.
"So this work and a lot of other similar work suggests we often don't know the types of influences that are affecting us with all types of decisions, including buying decisions," she says.
Her advice: save those receipts and re-evaluate purchases a day or a week later. "One day or one week later we'll be in a different state and may not be under the same influences we felt when we were purchasing. So by reevaluating, we can determine if we still value it at the amount that we paid and if not, we can return it," she says
Could such effects have implications for the economy? Cryder points out that while the participants were put into a shopping situation that they didn't seek out, the availability of online shopping may put us in similar situations even if we stay out of the stores.
"It's hard to tell exactly how strong the implications are until we're able to find out, do people put themselves in these shopping situations when they're sad, or not?" she says. But, "once they're in the situation, the emotions do have a strong effect. So it seems like to the extent that online shopping that people do in their own homes becomes more and more popular, that such a finding we know would have stronger implications in a broad economic sense."
Cryder says other, similar experiments have shown that while sadness can make us overvalue new purchases, it can also make us undervalue our own stuff.
"People will actually sell items that they own and that are associated with themselves already, for less," she explains. "So. I'll pay more for new things, but I value the thing that I own less when I'm sad. So it's all about things being associated with the self."
She says these emotions can influence all types of decisions, from career choices to relationships.
"We use the spending paradigm in our lab because...that's a clear demonstration of monetary differences so it's easier to draw conclusions," says Cryder. "But I think certainly in the real world, the implications go far beyond consumer decisions."
This research was published in the June 2008 issue of Psychological Science, and was funded by the National Science Foundation.