Has urbanisation made us sleep less?
Rural dwelling on a farm in Mozambique
Milange (town) market (Photos by Dr Andrew Beale)
Urbanisation and electrification do not decrease the amount that we sleep, a new study in the journal Scientific Reports has found.
In this study, researchers from the University of Surrey in collaboration with groups in South Africa, Brazil, Colombia, and USA examined the sleeping patterns of people from two neighbouring communities in Mozambique, the small electrified urban town Milange and the non-electrified rural community Tengua.
It has previously been suggested that the post-industrial world is experiencing a sleep deprivation epidemic. Scientists have proposed that people who have electricity stay up later, but do not necessarily get up later to compensate. The new research found that although the people in the town retired to bed on average one hour later, they didn't sleep less than the people in the village without electricity, because they also rose one hour later in the morning.
The study was performed by Dr Andrew Beale. Before he returned to the UK to work as a research fellow at the University of Surrey, he spent 2.5 years living in Milange. "I noticed that the sleep-wake patterns of people around me were much earlier than I was used to from the UK", Beale says. "There is an intense debate going on right now on how our ancestors might have slept, and how this was changed by industrialisation. Looking at the effects of urbanisation on these communities is one way of helping us understand what happens".
“What these findings indicate is that the delay in sleep timing that comes with access to electricity does not directly cause people to sleep less", commented Professor Malcolm von Schantz, the corresponding author. "In other words, if indeed people do sleep less in industrialised countries, we can't just blame electrification. The step from delayed to shortened sleep seems to require more changes in behaviours.”
Associate Professor Laura Roden from the Department of Molecular & Cell Biology at the University of Cape Town, senior author on the study, added: “We will probably never know how our ancestors slept. But as urbanisation spreads across the globe, it is important to study how people's sleeping habits change. After they've changed, it will be too late!"