Tremors in the Blood

Amit Katwala

HarperCollins

Otago Daily Times, August 6th 2022

The idea that we can tell when a person is lying based on various physical signs dates back thousands of years. Despite clear evidence that they are neither reliable nor valid, various forms of polygraph testing are used around the world today. How we arrived at this position is the subject of British journalist Amit Katwala’s history of the modern lie detector. 

In 1909, August Vollmer was appointed chief of police in Berkley, California. It was an era of policing characterised by ‘incivility, ignorance, brutality and graft’, and the changes Vollmer introduced earned him the title of ‘the father of modern policing’. More than anything, however, he wanted to ‘beat back the scourge of deception’, and after learning that lying stimulates detectible fluctuations in blood pressure, he commissioned a young officer called John Larson to investigate the possibility of developing this idea further. Larson was excited by the prospect of replacing the old-fashioned and brutal ‘third degree’ with a dispassionate, scientifically grounded way of determining a person’s guilt or innocence and the machine he and his assistant, Leonarde Keeler developed, the ‘cardio-pneumo-psychograph’ initially showed great promise. Eventually, Larson concluded that the lie detector did not work and became obsessed with debunking it. Keeler, however,  continued refining the machine and perfecting the psychological techniques that are the real key to the device’s success: a belief in its effectiveness in combination with sufficiently stressful questioning is often enough to elicit a confession from a suspect. And although Keeler, too, became disillusioned with his creation, his work – and showmanship – paved the way for the modern polygraph industry. 

A writer of narrative non-fiction must find a way to confine unruly reality within the bounds of a coherent and satisfying story without straying too far into the imagination. At the latter, Katwala succeeds, providing an extensive bibliography of the most useful of the “thousands of newspaper and magazine articles, private letters, diaries, academic journals, photographs, court documents, prison records, books, physical artifacts and interviews” on which this account is based. He certainly manages to synthesise these sources into a dispassionate and authoritative narrative, so much so that the few times in which he strays into people’s heads to describe what they are seeing or feeling jar, as do the occasional questionable assertions (I doubt, for example, that police photographers would be developing films in an open office).

The bigger problem is the book’s lack of focus. On the one hand, it is a biography of the men most closely associated with the development of the polygraph, whose lives and relationships are a drama in themselves. On the other, it is a police procedural/courtroom drama, diving deeply into the murder cases that destroyed first Larsen then Keeler’s faith in their detector. I would also have liked the concluding discussion of the various modern forms of polygraph to have gone deeper. That said, Tremors in the Blood introduces a branch of pseudoscience I am keen to investigate further.