It is often said that money doesn't bring happiness, but researchers may have found the two things that do - sex and sleep. The Living Well Index, developed by researchers Oxford Economics, found that spending time in the bedroom is a lot more significant than quadrupling your income. A poll 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. The report ... said: For the typical Brit, improving their sleep to the level of someone at the top of the index would be equivalent to them having over four times as much disposable income," adding that sleep was the "strongest indicator of a broader sense of well-being". Other factors include living in a strong community, job security and the health of close relatives. The analysis also found ... a strong association between happiness and having a young child at home. "Baby boomers" who were still in work were the second-happiest group because of good job security and a high standard of living. The survey of 8,250 adults also found that older people are objectively happier than younger ones - even when other factors, such as wealth and lifestyle, are controlled.