Millennials, prepare to catch more flack. According to a new study, you're horrendous at tipping.

After surveying 1,000 people, CreditCards.com found that 10 percent of adults ages 18-37 routinely don't leave any tip at all. When presented with preselected tip options (like on a tablet), one in six Millennials choose the lowest amount, and one in five choose to leave zero. And at restaurants, nearly a third of Millennials leave less than a 15 percent tip. Older age groups were more generous in all categories.

Before the Olds get high and mighty, the study contends that income, not age, is a better predictor of tipping habits. Simply put, Millennials make less money.

Tipping can be weird and the rules unclear, especially when it comes to non-restaurant settings like food trucks and Uber rides. But in most restaurants, servers depend on tips to make up for their shitty salaries. While there has been a push in the industry to eliminate tipping altogether, which is often discriminatory against people of color and women, it hasn't caught on so far—mainly because it would require restaurants to raise menu prices. However, the study found that Millennials were more open to going tip-less than older folks.

The study also found that the median tip left by women is 20 percent, but only 16 percent for men. And the most benevolent age group was seniors over the age of 65, over half of whom said they leave at least 20 percent tips in restaurants. (So maybe it's just your grandma who stiffs the staff.)

Just tip your damn server.

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