"Enhanced interrogation" may get someone to talk, but there's no evidence that it's the truth. A new book cross-examines the true consequences of torture

“IF YOU torture the data long enough,” the saying goes, “it will confess to anything.” Although this is a problem for scientists, the stakes are higher for torturers. If tortured people really will tell you anything, how do you know when they are telling the truth?

Why Torture Doesn’t Work has a specific origin, says its author Shane O’Mara, professor of experimental brain research at Trinity College Dublin in Ireland. In 2009, he read an article about the release of the “Torture Memos”, legal documents prepared for the US federal authorities on the use of waterboarding, sleep deprivation, binding in stress positions, and other “enhanced interrogation” techniques.

Morality aside, O’Mara wanted to know if there was credible science that showed torture worked. The answer, it turns out, is no. The reality is that “the intelligence obtained through torture is so paltry, the signal-to-noise ratio so low, that proponents of torture are left with an indefensible case”. Advocates defend torture with an “ad hoc mixture of anecdote, cherry-picked stories and entirely counterfactual scenarios”, he says.

Controlled studies on the effectiveness of torture would be morally abhorrent. But there is a lot of information on the psychological and physiological effects of severe pain, fear, extreme cold, sleep deprivation, confinement and near-drowning. Some studies, such as those on the effects of sensory deprivation, used healthy volunteers. Others were conducted during the training of combat soldiers.

There is also a small amount of literature on the severe, long-term effects of torture on those who survive it, and work on the efficacy of police-interrogation techniques, which has produced insights into the psychology of false confessions – alarmingly easy to produce.

As O’Mara emphasises, torture does not produce reliable information largely because of the severity with which it impairs the ability to think. Extreme pain, cold, sleep deprivation and fear of torture itself all damage memory, mood and cognition. Torture does not persuade people to make a reasoned decision to cooperate, but produces panic, dissociation, unconsciousness and long-term neurological damage. It also produces an intense desire to keep talking to prevent further torture.

O’Mara quotes an intelligence officer’s story about a 60-year-old torture survivor in Cambodia: “He told his interrogators everything they wanted to know, including the truth. In torture, he confessed to being everything from a hermaphrodite, and a CIA spy to a Catholic bishop and the King of Cambodia’s son. He was actually just a school teacher whose crime was that he once spoke French.”

“One survivor confessed to being everything from a hermaphrodite to the King of Cambodia’s son”

Interrogators often escalate torture when they think a suspect is withholding information or lying, but there is no good evidence that interrogators are better than the rest of us at detecting lies. In fact, there is evidence that when people are trained as interrogators, they become more likely to think others are lying to them. This belief can lead to alarming errors, whereby people are tortured because their torturer wrongly believes they are lying. New technologies to detect lies do not work either, says O’Mara.

Why Torture Doesn’t Work is a valuable book. O’Mara builds his case like a prosecutor, citing scientific studies and relentlessly poking holes in absurdities and inconsistencies in documents such as the “Torture Memos”. Whether science matters to those who defend torture is another matter, as O’Mara knows: their motivation is often punitive, not practical. But once torture is imposed, the consequences, he says, are that it will be “ineffective, pointless, morally appalling, and unpredictable in its outcomes”.

(Image: Vlad Sokhin/Panos)

Why Torture Doesn’t Work: The neuroscience of interrogation Shane O’Mara Harvard University Press

This article appeared in print under the headline “Secrets and lies”