Want your teenager to get better marks at school? Pay them to sleep, scientists say

If getting your grumpy teenager to bed feels like an impossible battle, scientists may have found an unlikely solution: pay them.

Researchers have discovered that offering students a small cash reward for getting at least seven hours of sleep a night can boost both their shut–eye and their grades.

For the study, a team from the University of Pittsburgh recruited more than 1,100 students with an average age of 19.

Some of them were paid the equivalent of around £3.50 each time they managed to sleep for at least seven hours on a weeknight.

Over the month–long experiment, those offered the cash bonus slept for an average of 19 minutes longer each night.

This extra sleep came from going to bed earlier rather than sleeping later in the morning, the study, published in the Journal of Political Economy, revealed.

But not only did they doze for longer, the teenagers also achieved a measurable improvement in academic performance.

On the American four–point GPA grading scale, where 4.0 represents straight As, the average improvement was about 0.08 points.

Some of the benefits even persisted after the payments stopped, with participants continuing to sleep slightly longer for several weeks afterwards.

Lead author Osea Giuntella told The Conversation: 'Our study shows that offering an immediate financial reward can help students meet a seven–hour sleep goal, and that those effects can persist up to a month beyond when the students are paid.'

Before the experiment began, the average student slept just 6.6 hours a night, with half regularly staying awake until after 1am.

The students who were offered nightly payments reached seven hours of sleep on 26 per cent more nights than the students who were not offered the money.

Other factors, such as bedtime reminders and morning feedback, had little effect.