It’s well known that the wealthy have more than the average human, including exorbitant real estate, sports cars and fine jewelry. But they also have more of something else — sleep.

Compared to those living near or below the poverty level, the rich sleep more too, according to a study by the US Centers for Disease Control and Prevention. The agency surveyed nearly 140,000 adults in the United States between 2011 and 2014 and found that the more money someone made, the more likely they were to get a full night’s rest.

Of the adults surveyed, only 55% of people living below the poverty threshold received seven to eight hours of sleep per night. For adults making 400% above the poverty threshold, that number rose to 66.6%. In 2014, the poverty threshold was $11,670 for a single-person household and $23,850 for a four-person household.

This particular study did not address the negative consequences of not getting enough sleep, said Lindsey Black, an epidemiologist at the CDC. However, there have been other studies that show multiple negative consequences from sleeping too little, she said.

“Sleep affects many aspects of well-being and quality of life for people of all ages,” Black said. Poor quality sleep has been associated with increased risk of diabetes and heart disease, mental health issues such as depression, and driving accidents, she said.

The study also did not look into why the rich sleep more than the poor, but Dr. Neil Kline, a sleep physician at the American Sleep Association, said there could be multiple reasons.

“People with more resources are able to afford homes that are in quieter locations — more space, less people-density and better sound-proofing,” Kline said. “People with more resources can also afford more healthcare when it relates to sleep disorders.”

Adults should be receiving between seven to eight hours of sleep per night, according to the American Sleep Association.

“Too often, we prioritize work and social events over our sleep,” Kline said. “When we don’t receive adequate sleep, we do not function at our peak and we increase the risk for poor health outcomes.”

One of the ways ASA recommends adults get better quality sleep is through creating a sleep schedule. Not waking up and going to sleep around similar times can make people have a higher risk of metabolic disorders, according to the ASA.

Another tip is to exercise. When you exercise, you sleep better, which in turn gives you more energy during the day to do activities like exercise. It’s a cycle of positive effects that keeps on giving.

Lastly, the ASA recommends people try to avoid naps when possible. Each individual has a certain number of hours they need to sleep per day, and when they nap, they decrease the number of hours they need to sleep at night. This, in turn can make it harder to fall asleep, which can lead to insomnia and sleep deprivation in the long term.