In the 20th century, secular chicken came before the economic egg

We have known for decades that secular countries tend to be richer than religious ones. Finding out why involves unpicking a complex knot of cognitive and social factors – an imposing task. So my small research team thought we’d ask a more straightforward question: was it the secular chicken that came first, or the economic egg?

Our recent paper in Scientific Advances shows that, in the 20th century, secularisation occurred before economic development and not the other way around. Although this doesn’t prove secularisation makes a country wealthier, it does rule out the reverse. The arrow of time points in one direction, so economic performance cannot be expected to influence people’s opinions in the past.

Global Gallup surveys give us a clear view of the relationship between secularisation and economic development – that the world’s poorest countries are also its most religious. But before the days of modern surveys, the steam-powered scholars of the early 20th century had already noticed that industrialised societies tended to be less religious than agrarian ones; though they disagreed on the interpretation.