Australasian Science: Australia's authority on science since 1938

In Search of Lost Sleep

By Tim Olds

Are we getting less sleep than we did in the past? And how much do we really need?

Professor Tim Olds leads the Health and Use of Time Group at the Sansom Institute for Health Research, University of South Australia.

The full text of this article can be purchased from Informit.

Try this: google “NGrams”, which searches millions of digitised books to track historical changes in the frequency of words and phrases. Now type in “not enough sleep”. You will see that the frequency of this phrase has risen from 46 per billion words in 1921 to a temporary high of 5995 per billion in 1944 (sleepless nights during the Second World War), plunging again to 1532 in 1967 (the summer of love), only to skyrocket to 7059 in 2000 – 153 times higher than the 1921 figure.

Sleep is on our minds more than ever. Sleep is like the dark matter of the use-of-time universe: we know it’s important, we know there must be more of it out there somewhere, but we’re not seeing it.

There’s nothing much to be said for poor sleep. It affects our attention, memory, creativity, learning and academic performance. It makes us more emotional, increasing our impulsivity, aggression and hyperactivity. Kids who sleep badly are at greater risk of alcohol and drug abuse and suicide risk as adults. Poor sleep compromises our immune systems, and increases our risk of overweight and obesity. Kids who don’t get enough sleep have trouble learning motor skills like serving a tennis ball.

So is it true what they say? Are we getting less sleep than we did in the past? Researchers from the University of Sydney looked at a series of adult time use studies across 15 countries, and...

The full text of this article can be purchased from Informit.