Average life expectancy may have dropped in the US and stagnated in the UK over the past couple of years, but on a global scale, we are living longer today than ever before in human history. Worldwide, life expectancy has more than doubled since 1900 to 70 years and while there is still a significant gap between rich and poor nations, no country on the whole of planet Earth has a life expectancy lower than the world's highest life expectancy at the turn of the 19th century, which was just 40 years and the average life expectancy of Belgians at the time.  

There are two conflicting theories attempting to explain this ginormous leap in global life expectancy. One, proposed in 1975 by Samuel Preston, suggests it's money and another, proposed in 1985 by John and Pat Caldwell, says it's education.

Now, new research, published in the peer-reviewed journal Population and Development Review and led by scientists Wolfgang Lutz and Endale Kebede from the IIASA and the Vienna University of Economics and Business (WU), has tested these two existing theories to calculate the best predictor of a long life – and they say it is education.

The pair used data from 174 developing and developed countries from 1970 to 2015. Stats on education were taken from the Wittgenstein Centre Data Explorer (WIC 2015) and info on income and mortality came from the World Development Indicators (World Bank 2017). The curves they built using the data show correlations between health and income as well as between health and education, but the latter was significantly more linear, implying education is a better predictor of a higher life expectancy than wealth. 

The researchers reasoned that better cognition – the result of a better education – is what leads to healthier lifestyle choices. 

"This paper is more radical than previous analyses in terms of challenging the ubiquitous view that income and medical interventions are the main drivers of health. It even shows that the empirical association between income and health is largely spurious," Lutz explained in a statement.

Of course, better-educated people also tend to enter higher-paid jobs and live in richer households, which makes living a healthy life easier. For example, 40 percent of Fortune 100 CEOs have an MBA, compared to 9.3 percent of Americans who have a postgraduate degree of any kind.

"The findings matter for the entire global health research community, and they matter for everybody in global development and deciding on funding allocations for the different aspects of development," Lutz added, saying funding education should be made a top priority.