Skip to Content
MIT News: 77 Mass Ave

Sleep on this

A field experiment suggests that a longer night’s sleep doesn’t necessarily improve your life.

October 26, 2021
asleep in hammock
A man sleeps in a hammock in Tosh, India.Sanket Barik / Pexels

Most of us feel that getting more sleep does us good, but a new study suggests that the reality is more complicated.

The researchers studied 452 low-­income workers in Chennai, India, at home during their normal routines—and managed to increase their sleep by about half an hour per night. The impact on their productivity, earnings, financial choices, sense of well-being, and blood pressure: zip. 

The only effect, apparently, was to lower the number of hours they worked.

“To our surprise, these night-sleep interventions had no positive effects whatsoever on any of the outcomes we measured,” says coauthor Frank Schilbach, an MIT economist.

One thing to bear in mind, though, is that participants tended to sleep in difficult circumstances. “In Chennai, you can see people sleeping on their rickshaws,” says Schilbach. “Often, there are four or five people sleeping in the same room, where it’s loud and noisy. You see people sleep in between road segments next to a highway. It’s incredibly hot even at night, and there are lots of mosquitos.” On average, participants woke up 31 times per night. 

That leaves open the possibility that helping people sleep more soundly, rather than just longer, could be useful. The research also showed that daytime naps improved productivity, executive function, and psychological well-being, though total income didn’t increase because nappers spent less time actually working. 

“It’s not the case that naps pay for themselves,” Schilbach says. Still, he adds, “I think a good night’s sleep is also important in and of itself. We should value being able to afford to sleep well and not be worried at night.”

Keep Reading

Most Popular

This new data poisoning tool lets artists fight back against generative AI

The tool, called Nightshade, messes up training data in ways that could cause serious damage to image-generating AI models. 

The Biggest Questions: What is death?

New neuroscience is challenging our understanding of the dying process—bringing opportunities for the living.

Rogue superintelligence and merging with machines: Inside the mind of OpenAI’s chief scientist

An exclusive conversation with Ilya Sutskever on his fears for the future of AI and why they’ve made him change the focus of his life’s work.

How to fix the internet

If we want online discourse to improve, we need to move beyond the big platforms.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at with a list of newsletters you’d like to receive.