It’s often said that money doesn’t bring happiness – but researchers may have found the two things that do. A study has found that sex and sleep are the two things that have the strongest association with a person’s wellbeing.

The index, developed by researchers Oxford Economics, found that quadrupling your income causes very little increase to your happiness, while spending time in the bedroom is a lot more significant.

Polling carried out by the National Centre for Social Research, found that the most rested people score 15 points higher on the index than those who struggled with their sleep.

People who are deeply dissatisfied with their sex lives score seven points lower on average than those who say they were very satisfied.

By the same metric, increasing household income from £12,500 to £50,000 results in an increase of just two points.