The Rules of Contagion

Why Things Spread – and Why They Stop

Bright red book cover with black and white text, featuring a vertical black arrow running down the middle and ‘2m’ in the centre of the arrow.

The new science of contagion and the surprising ways it shapes our lives and behaviour.

Why do some ideas take off – and others fail to spread? Why are some diseases predictable, and others swamped in uncertainty? And what about the outbreaks that never happen at all?

We live in a world that’s more connected than ever before. But even as we see our lives being shaped by the spread of ideas, trends – and even diseases – we sometimes struggle to grasp how it actually works. Outbreaks seem to be driven by randomness and hidden laws, and in order to understand them, we need to start thinking like mathematicians.

Here, epidemiologist Adam Kucharski reveals how new mathematical approaches are transforming what we know about contagion – from the revolutionary initiatives that helped tackle gun violence in Chicago to the truth behind the spread of fake news. And along the way, he’ll explain how innovations and emotions can spread through our friendship networks, what STDs can tell us about banking, and why some outbreak predictions go badly wrong.

“It is hard to imagine a more timely book… much of the modern world will make more sense having read it.”

The Times

“Brilliant and authoritative.”

Alex Bellos, author of ‘Alex’s Adventures in Numberland’

“Prepares the ground comprehensively for readers to make sense of what is happening today, by distilling the wisdom gathered by studying previous epidemics over more than a century.”

Financial Times

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About the author

Photograph of Adam Kucharski

Adam Kucharski

Adam Kucharski is an associate professor and Sir Henry Dale Fellow at the London School of Hygiene & Tropical Medicine, working on global outbreaks such as 2019-nCoV, influenza and Zika. He is a TED senior fellow and winner of the 2016 Rosalind Franklin Award Lecture and the 2012 Wellcome Trust Science Writing Prize. He has written for the Observer, Financial Times, Scientific American, and New Statesman. He is also the author of ‘The Perfect Bet: How Science and Maths Are Taking the Luck Out of Gambling’.