A bad night's sleep might do more harm than you think

It's 11 at night in a busy commercial section of Chennai, a city of nearly 5 million in Southern India. All around me people are sleeping in the open air. Men are curled up in the back of rickshaw wagons. Entire families camp out in shelters made of cardboard and tarp. A woman in a blue sari smiles and waves for me to come over.

She tells me her name is Anjalai — like some in this part of India, she goes by only one name — and says she's got the most basic setup: a woven blue mat laid out on a patch of dirt by the side of the street.

I ask her, "What's it like to sleep in this spot?"

Her smile fades.

"It's difficult," says Anjalai. "There's so much noise from vehicles coming through."

The traffic isn't the half of it. People have tapped the power lines to hook up televisions right on the street — the blare echoes late into the night. Drunks wander by, shouting incoherently. Loudest of all: the dogs.

This scene — masses of people sleeping by the side of a noisy road — is pretty typical across some of India's biggest cities. In fact you see it in low-income countries around the world.

So it's clear that poverty can lead to poor quality of sleep. But maybe there's more to the poverty/sleep relationship than that.

Just a few steps from Anjalai's spot is the office of an unusual social science lab that is testing an intriguing theory: Could the sleep deprivation experienced by so many poor people without a proper home actually be keeping them trapped in poverty?

Heather Schofield, an economist at the University of Pennsylvania, helped found the lab in Chennai along with MIT economist Frank Schilbach five years ago as a kind of base camp for on-the-ground research on the root causes of poverty. It's in a low-rise concrete building, just above a shop selling generators.

The more Schofield and her colleagues worked here — and saw all the people sleeping on the street — the more they started to wonder if one of those root causes of poverty might be lack of sleep.

"What does that do to you?" she wonders. "If you're at the level where you are that exhausted, how can you possibly function to be productive, to make good choices?"

Lab studies certainly suggest that getting too little sleep night after night can put a serious crimp in many of your brain functions. It's harder to keep focus, to remember things, to solve math problems. But Schofield says not much is known about the real-world impact that chronic sleep deprivation could have on how people make decisions.

"Does it change your preference over having stuff now versus having things in the future? Does it change how risk-averse you are?"

If so, adds Schofield, you might find it harder to resist buying drinks after work instead of saving your money. Or maybe being perpetually fatigued makes you avoid decisions altogether — like figuring out how to get training for better-paid work. Schofield has noticed that when she herself is tired, "I'll kind of put off choices that I know I should be making because I just don't have the mental energy to ... deal with them."

So Schofield, Schilbach, and another economist, Gautam Rao of Harvard University, have been setting up an experiment. They're recruiting poor people from the neighborhood around the lab for tests: How quickly can they do a computer task? Will they agree to give up payment today in exchange for higher pay tomorrow? Will they join a savings program? And most important, does the outcome change if the participants get more sleep?

But the researchers can't make any comparisons unless they find a way to actually improve the participants' sleep. The team started by testing out sleep aids. A research associate, Jane Marlen von Rabenau, shows me a few when I stop in at the lab for a tour: a pillow, an eye mask, earplugs, mosquito repellent. The list goes on.

They seem popular with some of the study participants who drop by.

Krishnamurthy is a 38-year-old rickshaw driver. By day he delivers sacks of vegetables loaded onto the back of a wagon attached to a tricycle. At night, he says, he sleeps in the wagon. And he found the eye mask and earplugs quite helpful.

"Before it would take me as long as two hours to fall asleep," he says. "But if I wear these things, in half an hour or even 15 minutes I'm asleep."

But the aids didn't work for everyone. So now the team is trying another option: naps. The researchers have set up cots in the office.

"It's a total of 12 beds right now, with foam mattresses," says von Rabenau.

Schofield says the team hopes to get preliminary results from that effort within a few weeks. But completing the full sleep study will take eight months to a year at the earliest — with an additional six months to analyze and publish the findings.

Editor's note: Heavy rains over the past two days have caused massive flooding across Chennai. The lab referenced in this story is located in one of the affected areas and has temporarily closed. This story was reported before those events. Copyright 2019 NPR. To see more, visit https://www.npr.org.