New analysis reveals intriguing insights into global sleep patterns, challenging long-held beliefs about the impact of modern lifestyles on sleep quality. A comprehensive review of 54 sleep studies indicates that individuals in small, non-industrialized societies often get less sleep than their counterparts in more industrialized regions.
Leela McKinnon from the University of Toronto Mississauga highlights the paradox many face in Canada and the US, where anecdotal evidence suggests poor sleep quality, yet data paints a different picture. The popular belief that gadgets like smartphones and large-screen TVs contribute to a “sleep-loss epidemic” may be misleading.
Studies tracking sleep through self-reported data are often unreliable, casting doubt on claims of decreased sleep over recent decades. However, research utilizing objective measures such as physical activity monitors and brainwave patterns show no significant decline in sleep duration. A notable 2016 review of 168 studies noted stability in sleep duration over the past half-century.
Recent advancements in technology, particularly wrist activity monitors, have allowed for more accurate assessments of sleep among non-industrialized populations. Surprisingly, hunter-gatherer societies report minimal sleep hours, with the Himba community in Namibia averaging just 5.5 hours a night, the shortest recorded so far.
McKinnon and her colleague David Samson have conducted several studies comparing sleep habits across various societies, encompassing both industrialized nations and smaller communities. Their findings reveal that individuals in non-industrial societies sleep approximately 6.4 hours on average, compared to 7.1 hours in industrial societies. Furthermore, sleep efficiency, defined as the proportion of time spent sleeping while in bed, stands at 74% for non-industrial populations versus 88% for those in industrialized areas.
The researchers also evaluated the consistency of circadian rhythms, with non-industrial communities averaging a score of 0.7 compared to 0.63 in industrialized societies. Samson attributes the generally longer sleep duration and greater efficiency in industrial regions to enhanced sleep environments, devoid of threats from predators or rival groups. Yet, he warns that lesser exposure to natural cues may disrupt circadian rhythms, potentially leading to perceived sleep quality issues.
While the analysis provides valuable insights, concerns remain about the representativeness of the study population, according to experts. McKinnon and Samson affirm that varying sample sizes would not significantly alter their findings, reinforcing the need for further exploration into sleep patterns across different cultures.
Topics:
