Being a bad tipper might not be such a bad thing — at least, in some circumstances.

Men, Republicans, Northeasterners, baby boomers and folks with credit cards or debit cards tend to be the most generous tippers, according to a new CreditCards.com report. People in those demographics tipped a median of 20 percent when dining out.

"What ties all of those groups together is that they tend to be higher income than some of their counterparts," said Matt Schulz, senior analyst at CreditCards.com. "I think when it comes to tipping, it generally comes down to income. The more money you have, the more willing you are to leave money at the end of the night."

The worst tippers in the CreditCards.com survey were women, Democrats, Southerners and people who paid with cash. Those demographics tipped a median 15 to 16 percent — which is still pretty good, Schulz said.

"When it gets right down to it, Americans are pretty generous when it comes to tipping at a restaurant especially when there's good service," he said. "Unless your service is an absolute disaster, it's pretty hard to justify not tipping at all."

And income does not necessarily dictate tipping behavior. Those who've worked in the service industry are also typically generous tippers, according to Jodi Smith, founder of Mannersmith Etiquette Consulting.

"People who tend to be more generous generally tended to be people who have waited tables or done a job requiring tips," she said.