How Much Sleep Is Enough? The Ideal Amount Varies by Culture

A global study challenges the eight-hour rule and highlights how cultural habits shape our nightly rest.

For decades, public health guidelines have insisted that sleeping eight hours a night is essential for physical and mental well-being. However, a recent Canadian-led study based on data from nearly 5,000 people across 20 countries suggests that this number may not be a universal benchmark.

Published in a journal focused on sleep neuroscience, the study analyzed sleep patterns and quality of life, revealing that the ideal amount of rest varies significantly from one country to another. The gap reached up to 1.57 hours between nations, showing the strong influence of cultural, social, and technological factors on our nightly habits.

“Sleep recommendations should be tailored to local cultural norms, rather than enforcing a single global standard,” the authors state. In other words, the human body responds not only to its biological clock but also to the social rhythm of its environment.

The report highlights striking contrasts: participants in Japan and South Korea slept much less than those in France or New Zealand. Latin America also showed distinctive patterns. In Colombia, for instance, participants tended to go to bed earlier than in any other country in the study, while those in Argentina had the latest bedtimes. Mexico and Costa Rica fell somewhere in between, with nightly routines strongly influenced by family dynamics and screen time.

Beyond bedtime differences, researchers pointed out that factors such as work pressure, fast-paced urban lifestyles, and screen exposure before sleep may reduce restful sleep—even in countries with high living standards.

These findings pose a challenge for public health policy: how can effective sleep recommendations be developed in such culturally diverse contexts? Experts believe the solution lies in moving away from a “one-size-fits-all” model and promoting sleep education that is sensitive to cultural realities.

Getting good sleep remains essential. But what “good” means may depend more than we realize on where we were born and live.