Getting a good night’s sleep is critical for healthy functioning. But sleep duration varies substantially around the world with some long-sleeping countries (e.g., the Netherlands, France) sleeping about 90 minutes per night longer than some short-sleeping countries (e.g., Japan, South Korea). Moreover, our research finds that people in shorter-sleeping countries do not have worse health than people in longer-sleeping countries. Rather, sleeping alongside local cultural norms predicts better health. Given the critical functions that sleep serves it is important to understand what leads cultures to adopt their sleep duration norms. One possibility is that sleep duration norms reflect broader cultural attitudes towards indulgence vs restraint. 

At a national level, countries that have higher levels of indulgent lifestyles (e.g., higher caloric intake, lower working hours, more drinking, etc.) tend to have longer sleep durations. We sought to investigate whether the same relations existed within countries as well. We compared self-reported sleep duration and a variety of measures of indulgent vs restrained lifestyles in 7 countries: Canada, China, France, Japan, Korea, the Netherlands, and the US. Results provided mixed support, suggesting there are other factors that predict sleep duration norms.