Denmark may have just have relinquished the title of world’s happiest country to Iceland, but it’s an accolade that’s been regularly awarded to the small Nordic nation since the 1970s.

And while by now we’ve all heard of hygge (and probably tried to achieve it buying candles in IKEA) and read about the country’s generous paternity rights, shorter working hours and established values of equality in the home with envy, it’s clear there is something else at play which ensures the Danes’ sense of contentment compared to our own.

In a recent blog for Psych Central, Lindsay Dupuis, a Canadian therapist working in Copenhagen, has pointed to a fictional concept called Jante Law which she thinks is to thank for the Danes’ happiness. The rules are defined in a satirical book called A Fugitive Crosses His Tracks, which was published back in the 1930s. They suggest that people should be modest, and find pleasure in the ordinary and everyday.

These 10 rules from the 1930s might explain why Danish people are so happy