WHEN we pick up a mythological text like “The Iliad” or “Beowulf,” we like to imagine that the societies they describe existed. Even if the stories are fiction, we believe that they tell us something about ancient Greece or the Anglo-Saxons, and that some of the characters and events were based on reality.

Archaeological evidence suggests that at least some of the societies and events in such stories did exist. But is there other evidence, lurking perhaps within the ancient texts themselves?

To investigate that question, we turned to a decidedly modern tool: social-network analysis. In a study published in Europhysics Letters, we use a mathematical approach to examine the social networks in three narratives: “The Iliad,” “Beowulf” and the Irish epic “Tain Bo Cuailnge.” If the social networks depicted appeared realistic, we surmised, perhaps they would reflect some degree of historical reality.

Social networks have been widely studied in recent years; researchers have looked at the interconnectedness of groups like actors, musicians and co-authors of scientific texts. These networks share similar properties: they are highly connected, small worlds. They are assortative, which means that people tend to associate with people like themselves. And their degree distributions are usually scale-free — a small number of people tend to have lots of friends.