How Polygraphs Work—And Why They Aren't Admissible in Most Courts

iStock/Sproetniek
iStock/Sproetniek

The truth about lie detectors is that we all really want them to work. It would be much easier if, when police were faced with two contradictory versions of a single event, there was a machine that could identify which party was telling the truth. That’s what the innovators behind the modern-day polygraph set out to do—but the scientific community has its doubts about the polygraph, and all over the world, it remains controversial. Even its inventor was worried about calling it a "lie detector."

AN OFF-DUTY INVENTION

In 1921, John Larson was working as a part-time cop in Berkeley, California. A budding criminologist with a Ph.D. in physiology, Larson wanted to make police investigations more scientific and less reliant on gut instinct and information obtained from "third degree" interrogations.

Building on the work of William Moulton Marston, Larson believed that the act of deception was accompanied by physical tells. Lying, he thought, makes people nervous, and this could be identified by changes in breathing and blood pressure. Measuring these changes in real-time might serve as a reliable proxy for spotting lies.

Improving upon previously developed technologies, Larson created a device that simultaneously recorded changes in breathing patterns, blood pressure, and pulse. The device was further refined by his younger colleague, Leonarde Keeler, who made it faster, more reliable, and portable and added a perspiration test.

Within a few months, a local newspaper ​convinced Larson to publicly test his invention on a man suspected of killing a priest. Larson's machine, which he called a cardio-pneumo psychogram, indicated the suspect’s guilt; the press dubbed the invention a lie detector.

Despite the plaudits, Larson would become skeptical about his machine’s ability to reliably detect deception—especially in regards to Keeler’s methods which amounted to “a psychological third-degree." He was concerned that the polygraph had never matured into anything beyond a glorified stress-detector, and believed that American society had put too much faith in his device. Toward the end of his life, he would refer to it as “a Frankenstein’s monster, which I have spent over 40 years in combating.”

But Keeler, who patented the machine, was much more committed to the lie-detection project, and was eager to see the machine implemented widely to fight crime. In 1935, results of Keeler’s polygraph test were admitted for the first time as evidence in a jury trial—and secured a conviction.

HOW IT WORKS

In its current form, the polygraph test measures changes in respiration, perspiration, and heart rate. Sensors are strapped to the subject's fingers, arm, and chest to report on real-time reactions during interrogation. A spike on these parameters indicates nervousness, and potentially points to lying.

To try to eliminate false-positives, the test ​relies on "control questions."

In a murder investigation, for instance, a suspect may be asked relevant questions such as, "Did you know the victim?" or "Did you see her on the night of the murder?" But the suspect will also be asked broad, stress-inducing control questions about general wrongdoing: "Did you ever take something that doesn't belong to you?" or "Did you ever lie to a friend?" The purpose of the control questions is to be vague enough to make every innocent subject anxious (who hasn't ever lied to a friend?). Meanwhile, a guilty subject is likely to be more worried about answering the relevant questions.

This difference is what the polygraph test is about. According to the American Psychological Association, “A pattern of greater physiological response to relevant questions than to control questions leads to a diagnosis of ‘deception.’” They proclaim that, "Most psychologists agree that there is little evidence that polygraph tests can accurately detect lies."

But a diagnosis of deception doesn’t necessarily mean that someone has actually lied. A polygraph test doesn’t actually detect deception directly; it only shows stress, which was why Larson fought so hard against it being categorized as a "lie detector." Testers have a variety of ways to infer deception (like by using control questions), but, according to the American Psychological Association, the inference process is “structured, but unstandardized” and should not be referred to as “lie detection.”

And so, the validity of the results remains a subject of debate. Depending on whom you ask, the reliability of the test ranges from near-certainty to a coin toss. The American Polygraph Association claims the test has an almost 90 percent accuracy rate. But many psychologists—and even some ​police officers—contend that the test is ​biased toward finding liars and has a 50 percent chance of hitting a false-positive for honest people.

NOT QUITE THE SAME AS FINGERPRINTS

Most countries have traditionally been skeptical about the polygraph test and only a handful have incorporated it into their legal system. The test remains most popular in the United States, where many police departments rely on it to extract confessions from suspects. (In 1978, former CIA director Richard Helms argued that that's because "Americans are not very good at" lying.)

Over the years, the U.S. Supreme Court has issued numerous rulings on the question of whether polygraph tests should be admitted as evidence in criminal trials. Before Larson’s invention, courts treated lie-detection tests with suspicion. In a 1922 case, a judge prohibited the results of a pre-polygraph lie detector from being presented at trial, worrying that the test, despite its unreliability, could have an unwarranted sway on a jury’s opinion.

Then, after his polygraph results secured a conviction in a 1935 murder trial (through prior agreement between the defense and prosecution), Keeler—Larson’s protégé—asserted that “the findings of the lie detector are as acceptable in court as fingerprint testimony.”

But numerous court rulings have ensured that this won’t be the case. Though the technology of the polygraph has continued to improve and the questioning process has become more systematic and standardized, scientists and legal experts remained divided on the device's efficacy.

A 1998 Supreme Court ruling ​concluded that as long as that’s the case, the risk of false positives is too high. The polygraph test, the court concluded, enjoys a scientific “aura of infallibility,” despite the fact “there is simply no consensus that polygraph evidence is reliable,” and ruled that passing the test cannot be seen as proof of innocence. Accordingly, taking the test must remain voluntary, and its results must never be presented as conclusive.

Most importantly: The court left it up to the states to decide whether the test can be presented in court at all. Today, 23 states allow polygraph tests to be admitted as evidence in a trial, and many of those states require the agreement of both parties.

Critics of the polygraph test claim that even in states where the test can't be used as evidence, law enforcers often use it as a tool to ​bully suspects into giving confessions that then can be admitted.

“It does tend to make people frightened, and it does make people confess, even though it cannot detect a lie,” Geoff Bunn, a psychology professor at Manchester Metropolitan University, told The Daily Beast.

But despite criticism—and despite an entire ​industry of former investigators offering to teach individuals how to beat the test—the polygraph is still used ​widely in the United States, mostly in the process of job applications and security checks.

Surprise! Microsoft Admits That People Are Listening In on Your Cortana and Skype Conversations

mabe123/iStock via Getty Images
mabe123/iStock via Getty Images

In a turn of events that, at this point, probably shocks no one, Microsoft has confessed that human contractors have been listening in on some people's private conversations via Skype and Cortana.

Vice first broke the news on the privacy breach earlier this month, after a contractor passed along documents, screenshots, and actual audio files of some conversations. “The fact that I can even share some of this with you shows how lax things are in terms of protecting user data,” the contractor, whose name was withheld (for obvious reasons), told Motherboard. Unlike Apple’s recent Siri snafu, these conversations didn’t include potential criminal activity, but they did catch intimate exchanges about weight loss, love, and relationship problems.

Also unlike Apple: Microsoft is not suspending its practices. Instead, the tech monolith has updated its privacy policy to clarify that humans might, in fact, be eavesdropping on you.

“We realized, based on questions raised recently, that we could do a better job of clarifying that humans sometimes review this content,” a Microsoft representative told Vice. Before, the Skype website had mentioned that your content could be analyzed in order to improve the technology, but it never explicitly stated that humans would be listening to it.

Microsoft only records Skype conversations that use its translation features, in order to “help the translation and speech technology learn and grow,” according to the Skype FAQ section. If you’re not using translation features, your sweet nothings are reportedly as private as you want them to be. The updated FAQ section also now states that “Microsoft employees and vendors” may be transcribing the translated audio, and the procedures are “designed to protect users’ privacy, including taking steps to de-identify data, requiring non-disclosure agreements with vendors and their employees,” and more.

But Cortana’s data gathering isn’t limited to translation. According to its support page, Microsoft can collect your voice data literally any time you “use your voice to say something to Cortana or invoke skills.” If that worries you, we recommend spending some time adjusting the settings on your Microsoft Privacy Dashboard.

[h/t Vice]

Amazon Is Making It Easier for Sellers to Donate Returned or Unsold Items Instead of Trashing Them

ronstik/iStock via Getty Images
ronstik/iStock via Getty Images

After mailing back an unwanted Amazon order or bringing it to a drop-off location, you may assume your return will find its way to a good home. But not every item returned to Amazon is re-listed on the website. Many third-party sellers working through Amazon simply toss returned products in the trash along with any surplus goods they can't sell. That's about to change: As CNBC reports, the retailer will make its new Fulfillment by Amazon (FBA) Donations program the default option for independent shops based in the U.S. and the UK.

Starting in September 2019, sellers that have unwanted returns or unsold items sitting in an Amazon warehouse can depend on the company to donate them to a good cause. In the U.S., products that are eligible for donation will be sent to various nonprofits through a charity group called Good360, and in the UK, groups including Newlife, Salvation Army, and Barnardo will distribute the goods.

“We know getting products into the hands of those who need them transforms lives and strengthens local communities,” Alice Shobe, director of Amazon in the Community, said in a statement. “We are delighted to extend this program to sellers who use our fulfillment services.”

Amazon charges independent sellers 50 cents to ship unsold items back to them and just 15 cents to throw them away, meaning that donating or trying to resell returned items wasn't always cost-effective for businesses. Amazon reportedly wasted 293,000 products over a nine-month period in just one French distribution center alone.

The company now aims to incentivize sellers to donate their unsold and returned inventory by making it the cheaper option, according to sellers who spoke to CNBC. As part of this program, Amazon will also manage the logistics and work with charities in an effort to "streamline the donation process for independent sellers."

The Fulfillment by Amazon Donations program will be the default for U.S. and UK sellers starting on September 1, but stores will still have the opportunity to opt out if they wish.

[h/t CNBC]

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