The inequality of sleep

Racial inequality. Income inequality. We now have a new contributor to inequality in the U.S. – and it’s closer to home than you think.

The most recent CDC data reveals that there is an inequality gap in our sleep. The long and short of it is this: wealthy white people enjoy better sleep than poorer people of other races.

Their survey of nearly 500,000 American adults revealed direct relationships between household income and sleep, as well as between race and sleep. your race have a direct relationship with the length and quality of your sleep.

Keep reading to understand what explains this sleep inequality epidemic, and why it matters.

Sleep inequality in America: a review of the research

In their most recent Behavioral Risk Factor Surveillance System, a regular survey the CDC conducts to assess the health of our nation, they asked 444,306 adults in all 50 states and DC about their sleep patterns.

Overall, more than one-third of adults regularly reported sleeping fewer than the recommended 7 hours minimum, leading the CDC to declare sleep deprivation a public health epidemic. Unfortunately, it also appears to be a socioeconomic epidemic.

Income disparity in sleep

The CDC looked at how poverty affected sleep. When defining “poverty status,” the CDC looks at where your income lies in relation to the federal poverty threshold. At the time of the survey, the federal poverty threshold was $11,670 for a single-individual household and $23,850 for a four-person household.

As you can see, the likelihood of short sleep increased with greater poverty:

Poverty Status Percentage of Respondents Sleeping Less than 7 Hours
Household income 4x above the poverty threshold 26.8%
Household income 2x to 4x above the poverty threshold 30.4%
Household income at or 2x above the poverty threshold 32.2%
Household income below the poverty threshold 33.6%

Racial disparity in sleep

The CDC also found an association between race and short sleep. Short sleep was most common among Native Hawaiians and Pacific Islanders, who were a full 13 percentage points above white sleepers:

Race/Ethnicity Percentage of Respondents Sleeping Less than 7 Hours
White 33.4
Hispanic 34.5
Asian 37.5
American Indian/Alaska Native 40.4
Other/Multiracial 44.3
Black 45.8
Native Hawaiian/Pacific Islander 46.3

Other studies

Although the CDC data is authoritative enough on its own, a wealth of academic research validates their findings.

A 2010 study of nearly 10,000 individuals likewise found a strong relationship between income level, ethnicity, and sleep quality. African-American and Latino participants were over 50% more likely to experience poor sleep than white participants, and those below the poverty level were almost 3 times as likely to experience poor sleep than the wealthiest participants.

Another 2013 survey of over 4,000 individuals assessed how socioeconomic factors affected individual sleep issues, such as snoring or difficulty falling asleep. Key findings included:

  • The people most likely to have a tough time falling asleep at night (taking 30 minutes or longer) were black, didn’t have private insurance, or experienced food insecurity (the last two of which are indicators of poverty).
  • Food insecurity was additionally tied to difficulty staying asleep, awakening too early, or feeling unrefreshed from sleep.
  • Snoring was more prevalent among individuals who identified as non-white Hispanic, had less education, or experienced food insecurity.

A smaller 2013 study of 164 adults found that African Americans spend 5% less time in deep sleep and more time in light sleep than white Americans. Deep sleep is an important stage of sleep for our physical health, since it’s during this stage that our body restores and repairs itself from the strains of the day.

race vs deep sleep

Participants were also surveyed about whether they felt they experienced discrimination due to their race or ethnicity. Individuals who felt they experienced more discrimination tended to be the ones who got less deep sleep.

Another study of nearly 700 participants found that black adults get up to 1 full hour less of total sleep per night.

The same researchers also found a correlation between better sleep and higher income levels. In the graph below, the “1 income level” equates to $16,000 while “7 income level” represents those making over $100,000. Notably, lower income level participants spent more time in bed, but slept significantly less, suggesting that more of that time may be spent experiencing the kind of anxiety and worry that contributes to insomnia.

household income vs sleep time

Even arguably non-academic research backs up these findings. In 2018, the Harvard Business Review surveyed 35,000 business leaders and found a correlation between sleep quantity and business role. The more senior their role, the more that person sleeps, with senior executives getting the most sleep of all. Considering that senior executives also tend to have extremely high household incomes, these findings jibe with the CDC data.

What's causing America's sleep gap?

The problem with the sleep gap in America is that it’s a cyclical problem. People who are not white and poor are dealing with a significantly higher amount of disadvantages that conspire to make getting adequate sleep much more difficult. Some of these contributing factors include:

Less time for sleep

People who are poor typically work multiple jobs in order to make ends meet. When you’re working a day job and a night shift somewhere else, you have simply have less time for sleep. Plus, as gentrification continues to push lower-income individuals away from the center of the city – where the jobs are – their work is likelier to be coupled with longer commutes. Even with public transportation, the farther you travel, the higher the cost to get to work, draining an already stretched low income.

About 15% of the American workforce works multiple jobs. These people are 61% more likely to sleep fewer than 6 hours on a weeknight, since more of their time is spent working multiple jobs and commuting to them. These people are also more likely to have irregular work hours, begin work earlier and end it later than others, preventing them from following a regular sleep schedule.

Studies show that individuals who work multiple jobs also tend to have disrupted circadian rhythms, since they’re more likely to work longer and later at night. This increases their risk for on-the-job injury, and makes it tougher to fall asleep when they need to.

Poor health

Multiple studies have linked poverty level and minority races with worse health outcomes. Unfortunately, better food costs more, and it’s often more than poor people can manage.

With lower-quality diets comes lower-quality sleep. Overly sugary, fatty, or otherwise junky foods are terrible for sleep and overall health.

Over time, eating an unhealthy diet often develops into obesity, which in turn increases your risk for other chronic health issues like diabetes. Obesity is also a major risk factor for snoring or sleep apnea, either of which result in lower-quality sleep as well.

Home environment

Non-white people can experience a harder time finding better jobs and housing due to discrimination. Housing insecurity can lead to instability at home, which increases stress for all household members. Children are at particular risk, as a way out of poverty can be better education, but if a stressful home life is interfering with their sleep, they’re more likely to miss school, or experience impairments to their academic performance due to sleep deprivation.

Poorer neighborhoods also tend to be poorer environments for sleep. They’re typically crowded and more urban, which means more light pollution and noisier living quarters. An ideal bedroom environment is one that is cool, dark, and quiet – and noisy urban neighborhoods typically don’t fit the mark.

Lower education

While it’s less of a one-to-one relationship as with household income, education level also appears to be related to sleep inequality. In some ways, this makes sense, as more education tends to correlate with higher household incomes (although not always).

According to one study, individuals with graduate-level degrees or higher are the most likely to enjoy healthy sleep. 70% of them sleep between 7 to 8 hours a night, with bachelor degree holders close behind at 67%. From there, it’s a big drop: fewer than 60% of people with an associate’s degree or less regularly get healthy sleep.

Mental health

Reduced mental health has been documented at higher levels among the poor. Up to 25% of the country’s homeless population suffers from severe mental illness – compared with only 6% of the general population.

Worse, when people are poor, they are less likely to receive treatment for their mental health, This could be due to a variety of things, including no free time to visit the doctor, a lack of insurance, or a general inability to pay. As a result, their mental health worsens, further interfering with their quality of life and their sleep.

The stressors of poverty can lead to mental health issues in the first place, such as anxiety and depression. Sleep problems are a common side effect of many mental health disorders, including anxiety, depression, and bipolar disorder.

Increased stress

People living in poverty often experience food insecurity, housing insecurity, and even insecurity about the neighborhood in which they live. If you are worried about being able to buy groceries for dinner tomorrow, paying your rent, or making it home safely, you’re living in a state of constant stress.

Stress activates your nervous system, making you feel alert, so when you do have time to sleep, it’s much harder to relax sufficiently in order to fall asleep. No surprise then, that people who feel they live in safer neighborhoods tend to report better sleep quality.

Why sleep inequality is a socioeconomic issue

Sleep inequality is a serious issue because it creates a vicious cycle, wherein socioeconomic factors contribute to people getting poorer sleep, and then that poorer sleep makes it harder for them to overcome their socioeconomic disadvantages.

Regularly sleeping fewer than 7 hours leads to chronic sleep deprivation, which is linked with a variety of mental, emotional, and physical health consequences. People who are sleep-deprived are at increased risk for long-term health conditions, including obesity, diabetes, cancer, and cardiovascular disease. Many of these same health conditions are also more common among black populations.

People who are sleep-deprived experience impairments to their cognitive performance, affecting their ability to succeed at school and work. In large part, this is due to reduced REM sleep. As we sleep, we cycle through different stages of sleep, one of which is REM. REM sleep is concentrated in the latter half of the night, so when you cut your sleep short, you lose out on REM sleep most of all.

REM sleep is the stage of sleep where you dream, and it’s also the time when your brain processes information from the day, deciding what to keep and what to throw away. REM also affects your focus and emotional stability. With less REM sleep, your memory, decision-making, and mood all suffer – making you less capable of coping with the stressors common to poverty.

Some researchers call this the “burden of poverty.” Both lower cognitive function and poverty are independently associated with poor sleep – it was only a matter of time before someone linked the two directly. Poverty itself takes up mental energy and time, consuming your focus while making you mentally exhausted. When people are sleep-deprived, it’s already for more difficult for them to focus and concentrate. If you’re compounding the effects of sleep deprivation with poverty, you’re essentially adding insult to injury.

Clearly, sleep inequality is a complicated problem. Poverty and racism set people up for poor sleep, and that poor sleep makes their lives even more difficult. Prior to these studies, we knew poverty, racism, and sleep deprivation were all issues affecting individual Americans. Now, we know that these issues in turn affect each other. Hopefully, with more education and awareness, our policy makers will make strides to improve these conditions.  

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