Ken Alder


On his book The Lie Detectors: The History of an American Obsession

Cover Interview of July 12, 2009

In a nutshell

I did not write this book to “debunk” the lie detector.  Eminent psychologists have been trying to do that for eighty years, ever since interrogators first re-purposed some basic physiological apparatus to measure subjects’ bodily responses—their blood pressure, pulse rate, breathing depth, and sweatiness—while obliging them to answer probing questions.  Likewise, the U.S. courts have consistently refused to allow this sort of polygraph evidence into criminal trials.  Yet the lie detector lives on.  It is used in criminal investigations, to gauge loyalty in the workplace, to protect national security, and as a publicity stunt.  At one point, Americans were turning to this mechanical oracle some two million times a year.


At the proximate level, the answer lies in the nation’s admirable effort to reform the police.  The lie detector apparatus and questioning procedures were first assembled in the 1920s in Berkeley, California by two disciples of August Vollmer, the father of modern professional policing.  Vollmer’s goal was to substitute this new and humane scientific technique for the traditional (and brutal) third-degree interrogations.  They both shared Vollmer’s grand ambition of making the police themselves law-abiding, and soon turned the instrument against the police.

But Vollmer’s disciples differed as to how the lie detector was to be deployed in practice.

One, John Larson, was the nation’s first Ph.D. cop.  He hoped to use the lie detector to probe the psyche of criminals and perhaps even create a therapeutic cure for deceit.  The other, Leonarde Keeler, named after Leonardo da Vinci, but widely known as “Nard,” was a local high school kid and amateur magician who adapted the lie detector to get what cops and prosecutors had always wanted from suspects: confession.  The two men started out as friends and wound up bitter enemies.

My book uses the diverging biographies of these two to address what it is about America that makes us take a Rube Goldberg approach to one of life’s most enduring mysteries: the hidden thoughts of another person.