22 February 2012 Updated at 11:58 ET
The myth of the eight-hour sleep
Stephanie Hegarty
BBC World Service
We often worry about lying awake in the middle of the night - but it could be good for you. A growing body of evidence from both science and history suggests that the eight-hour sleep may be unnatural.
link-
http://www.bbc.co.uk/news/magazine-16964783