'Back in the 1960s, long before the denizens of Silicon Valley were infiltrating every facet of our lives, the smart men and women of The Simulmatics Corporation were creating algorithms to predict and even influence human behaviour. Jill Lepore reveals how this forgotten company invented the data-weapons of the future. If Then is simultaneously gripping and absolutely terrifying' Amanda Foreman 'An authoritative account of the origins of data science, a compelling political narrative of America in the Sixties, a poignant collective biography of a generation of flawed men - Jill Lepore's If, Then represents not only a stunning achievement in itself, but a stirring defence of the humanities in our techno-reductive age' David Kynaston 'A person can't help but feel inspired by the riveting intelligence and joyful curiosity of Jill Lepore. Knowing that there is a mind like hers in the world is a hope-inducing thing' George Saunders, Man Booker Prize winning author of Lincoln in the Bardo 'Jill Lepore is the pre-eminent historian of forgotten tales from America's past that throw startling light on the present. This brilliant book illuminates the future too. The story of the original data science hucksters of the 1960s is hilarious, scathing and sobering - what you might get if you crossed Mad Men with Theranos. It's a reminder, in the age of Cambridge Analytica and whatever comes next, that we have been here before and should know better.' David Runciman The Simulmatics Corporation, founded in 1959, mined data, targeted voters, accelerated news, manipulated consumers, destabilized politics, and disordered knowledge--decades before Facebook, Google, Amazon, and Cambridge Analytica. Silicon Valley likes to imagine it has no past but the scientists of Simulmatics are the long-dead grandfathers of Mark Zuckerberg and Elon Musk. Borrowing from psychological warfare, they used computers to predict and direct human behavior, deploying their "People Machine" from New York, Cambridge, and Saigon for clients that included John Kennedy's presidential campaign, the New York Times, Young & Rubicam, and, during the Vietnam War, the Department of Defence. Jill Lepore, distinguished Harvard historian and New Yorker staff writer, unearthed from the archives the almost unbelievable story of this long-vanished corporation, and of the women hidden behind it. In the 1950s and 1960s, Lepore argues, Simulmatics invented the future by building the machine in which the world now finds itself trapped and tormented, algorithm by algorithm.