Early risers wake up because of their body clock. Researchers said early risers share DNA with Neanderthals – our ancestors from 40,000 years ago. They woke up earlier to gather food as the sun rose. A researcher said a "faster" body clock makes people "more likely to rise early".

The researchers looked at genetic information to find out why some people are early birds and others are night owls. The Neanderthal DNA may weaken as time passes. Modern life means many of us prefer to sleep in. We are becoming night owls. Nevertheless, it is true that the early bird catches the worm.