Rutherford and his colleagues used two kinds of computer analyses to look for patterns in provisions from the constitutions of 194 countries. In one, using hand-coded text, they found that the number of provisions increased over time (see ‘Evolution of constitutions’). Moreover, the team found that provisions generally appeared in a particular order. Making education compulsory, for example, was usually preceded by the establishment of a right to a free education.

Some of the sequences were less straightforward: the right to form trade unions preceded laws against child labour, for example. This progression probably reflects the identities of the people who have traditionally scripted constitutions, says Rutherford. Adult men, for instance, seem to have considered their own protections before thinking about others, including those who were unable to push for their own rights, he says. “I think we should protect the most vulnerable first, but this paper says this is not how laws have progressed historically.”

The team then performed a network analysis to identify words that the constitutions had in common and to detect how they grouped together. In some cases, with fundamental provisions such as freedom of religion, clusters included countries that had the same former colonizers.