A happy childhood can help people to a higher-earning and successful career in later life, a new study has revealed.
According to the new research, the relationship between happiness and money is far more complex than has been appreciated.
Two leading economists claim that happiness makes people earn more, possibly because happier people are more productive and are promoted faster.
Jan-Emmanuel De Neve of University College London and Professor Andrew Oswald of Warwick University examined the earliest years of thousands of randomly sampled people and found that, even when other factors were taken into account, their happiness levels when young clearly determined the likelihood of whether they would go on to enjoy higher earnings later in life.
The pair's work, the first in-depth investigation into the extent to which happiness is a predictor of income a decade later on, draws on the "life satisfaction" levels of a large sample of adolescents and young adults in America and tracks this against their levels of income later in life.
Their analysis shows, for example, that a one-point increase in life satisfaction (on a scale of five) at the age of 22 is associated with almost 2,000 dollars of higher earnings per annum by the age of 29.
Their study of 90,000 people speculates that one reason for the causal link may be that people with sunny dispositions are more likely to get a degree, get hired and get promoted.
They compare siblings' data to show that happier siblings tend to grow up to earn higher levels of income.
Their results, which consider other factors such as education, physical health, genetic variation, IQ, self-esteem and current happiness, show that the effect of individual happiness on income is greater than the widely acknowledged influence of income on happiness.
"These findings have important implications for academics, policy-makers and the general public," the Guardian quoted them as writing.
"For academics, these results reveal the strong possibility for reverse causality between income and happiness - a relationship that most have assumed unidirectional and causal," they said.
The study will be been presented at the Royal Economic Society's annual conference at the University of Cambridge. (ANI)