Millennials and young adults are careful with debt and credit cards, and some avoid credit cards completely. Many believe being financially successful means being debt-free.

Facebook IQ, a data-gathering source from the social media website, found many millennials actually hate debt and have negative attitudes about credit cards too.

Debit Not Credit

Millennials are three times more likely to use a debit card or cash than a credit card to make a purchase, according to Money Under 30. These young adults avoid using credit cards to pay for everyday expenses like lunch, gas or groceries, according to a poll run by Money Under 30.

Just One Card, Please

Young adults not only avoid accumulating balances on their credit cards, they also keep down the number of the cards they have. Of those surveyed, 23.8 percent had only one credit card and 26 percent had two cards. Many young adults (26.4 percent) said they did not have any credit cards, according to the Money Under 30 study.

While millennials talk about their financial situations with their friends on Facebook, most do not seek out financial advice from professionals. Only 37 percent of millennials said they have a financial plan for the future. In this age group, 86 percent put money aside into their savings account every month, but they are unlikely to invest that money.

No Trust in Banks

Millennials experienced the Great Recession and learned about how money works during that period of economic uncertainty. As a result, many are distrustful of big banks and established financial insitutions. According to a recent study called the "Millennials Study," 22 percent of millennials said they would never open a bank account, Banking My Way reports.

Of those millennials investing their money, most are doing so with online brokerages using automatic investments and low fees, instead of hiring a financial adviser in person.

Paying Off the Whole Balance

Most young adults are paying off their entire credit card balances every month and are rarely paying the minimum payment, with 53 percent saying they pay off the entire balance each month.

When millennials use credit cards, they prefer to use them for emergencies and convenience, but also to accumulate credit card rewards like airline miles or cash back. When considering a new card, most millennials say the rewards advertised are the most important feature.

Avoiding Debt, Taking Control

Millennials avoid debt and prefer to pay with debt cards or cash. This group of consumers try to avoid spending money they do not have and keep control of their financial situations.

Even though some millennials are being responsible by not having any credit cards, they could be missing out on important benefits. Responsible use of a credit card helps build good credit history, which can help a young adult purchase a car or home later in life.