Stephen Dubner is the journalist who, together with economist Steven D Levitt, wrote the best-selling popular economics books Freakonomics and Superfreakonomics.

Explaining how he came to meet his collaborator, the wild-haired writer, who slightly resembled Tim Burton in his rumpled suit, showed a slide that would recur frequently throughout the evening: the owlish Levitt, with a sensible haircut and buttoned-up shirt, peering benignly through large glasses.

Levitt, Dubner explained mildly, was most at home in the world of regression analysis, poring over data and crunching numbers – “the kind of person who would not do well in a town like Brighton”.

The child of a psychic and an authority on intestinal flatulence (“The Fart King”), Levitt’s uncanny way of looking at the world fascinates Dubner: before writing their first book, he calculated the expected value of doing so with a complex equation we were invited to marvel at.

Dubner made an engaging speaker, turning the lights up to challenge audience members on their hand-washing frequency and altruistic tendencies in “the dictator game”, before producing contradictory statistics showing that real life was more complex and unpredictable, with multiple factors affecting human behaviour.

The idea of prophets being ignored in their own time recurred, from Dubner’s early poor book reviews to the example of historical hand hygiene in hospitals.

After taking a couple of questions, Dubner told an extraordinary story about a study of capuchin monkeys – impulse-driven “bottomless stomachs of want”. An economics student taught them that coins could be exchanged for food, but when coins were accidentally spilled, the impromptu monkey economy that quickly developed included the first known example of monkey prostitution.

On this astonishing note, amid hysterical applause from the audience, Dubner left the stage and sprinted to the book signing table, where a giggling group serenaded him with an impassioned rendition of Superfreak.