Young adults on average make less than those further along in their careers, but income alone is unlikely to be the sole factor behind the findings, based on an online survey of 1,000 adults during a three-day period in May.
Younger Americans are more likely to be supportive of getting rid of the practice of tipping altogether, an approach that is being tried at some restaurants, but is by no means a major trend.
Tipping, a practice treated as standard in the U.S. but not so much in other countries, is increasingly being questioned, given research that shows a server's age and appearance has much to do with how much one earns in tips.
"We're seeing younger adults tipping less, and even showing a greater preference toward eliminating tipping altogether, even if it means paying more on the bill," said Matt Schulz, a senior analyst at CreditCard.com.
Other demographic groups that are more open to doing away with tipping includes Americans who make more than $75,000 a year and those with college degrees, with 26 percent of the former in favor of the idea and 30 percent of the latter.
The Emily Post Institute calls tipping "one of the most stressful and confusing aspects of etiquette today." The longtime voice on etiquette recommends tipping 15 to 20 percent on the pre-tax tab at sit-down restaurants.