Repeated acts of indulgence may contribute to rising credit-card debt among impulsive consumers in the U.S. who don't feel guilty about succumbing to temptation, according to a study.

Prudent and impulsive consumers display different emotions when they splurge, the authors said in the August issue of the Journal of Consumer Research. Impulsive people remember the pleasure of their decisions for a long time, while the prudent ones experience strong negative and self-conscious emotions.

"What happens to the guilt and regret when they see the consequences of their actions on their credit-card bills?" Suresh Ramanathan, associate professor of marketing at the University of Chicago Graduate School of Business, said in a telephone interview. "Why do people binge?"

Consumers boosted their borrowing more than expected in June, reflecting another hefty jump in credit card debt. The Federal Reserve reported Tuesday consumer credit rose at an annual rate of 6.5 percent in June. Consumer credit rose by an even larger 7.9 percent in May.

The academic study disclosed that people who repeat acts even as they experience a sense of guilt are capable of "laundering" their emotions, Ramanathan said.

"They have a mechanism to get rid of guilt and they're not looking for external crutches."

Prudent consumers, on the other hand, may buy an expensive pair of shoes and then contribute to charity or make a utilitarian purchase to help them cope with their negative emotions, he said.

"Over time, impulsive consumers are left only with their positive feelings about indulging, while prudent consumers are left only with their negative feelings about indulging," Ramanathan wrote. "This, in turn, affects propensity to repeat an act of indulgence." The two-part study included 293 University of Pennsylvania students.

In Tuesday's report, total consumer credit rose by $13.2 billion in June to a record $2.459 trillion. The increase was double what economists had been expecting.

Consumer credit as measured by the Fed does not include mortgage debt.

The Associated Press contributed to this report.