Why are millennials reluctant to use credit cards?

A new survey finds those between the ages of 18 and 29 have been shying away, big-time, from using plastic for purchases.

The Bankrate.com survey of millennials finds greater than six in 10 of them do not even own a credit card, and they are the least likely age group to pay monthly balances in full. Jeanine Skowronski, Bankrate's credit card analyst, said only 40 percent of millennials pay their full balance each month. That compares to 53 percent of adults age 30 or older.

Skowronski said some millennials may have seen and heard too much about all of the debt problems created during the Great Recession, and that's why they're backing away from credit card use.

"They see it really as a debt instrument, and you know, you have to kind of shift your mindset and think of it as a way to transact," she said, while pointing out that forgoing credit card ownership could cause financial troubles for these teens and 20-somethings.

According to Skowronski, the way of the world is to build a strong credit score as you move through life, and the care and feeding of a credit card is part of that process. She said future big-ticket purchases such as cars or homes may revolve around a good credit score; the same holds true for getting insurance policies, loans, or even jobs.

She says many millennials are also saddled with student loan debt, making them more gun-shy about plastic. Three percent of millennials often miss monthly loan payments altogether.

One other reason younger adults may be sticking with other methods of payment is legislation like CARD -- the Credit Card Accountability, Responsibility and Disclosure Act of 2009 -- which simply makes it more difficult for those under age 21 to obtain credit cards.