Since the early 1990s, criminal convictions nationwide have been based in part on an “outlandish mindreading tool” that has never been proven to deliver accurate results. In fact, studies have revealed that the tool is as effective as “flipping a coin.”
That’s the conclusion of a recent report by ProPublica, an independent, nonprofit investigative journalism organization.
The investigative method, called SCAN, analyzes written answers in an attempt to find deceptive statements. Individuals who are trained to use SCAN then evaluate the answers to determine whether respondents are telling the truth.
SCAN has website that appears to have been created in the early 1990s. The site makes amazing statements, including:
- “SCAN unlocks the Mystery !” (sic)
- “SCAN is the original technique for analyzing statements. Don’t accept any imitations!
- “SCAN will solve every case for you quickly and easily.”
- “Turn every investigator into a walking polygraph!”
Nationwide, government organizations of all sizes and types pay SCAN for training. In 2014, the U.S. State Department, for example, paid $132,500 for staff training.
SCAN is like flipping a coin
In 2011, independent researchers examined SCAN. Using control groups, the evaluation revealed that SCAN is completely unreliable. In other words, it is useless.
Then in 2016, four scholars published a study on SCAN in the journal “Frontiers in Psychology.” “The authors noted there had been four prior studies in peer-reviewed journals on SCAN’s effectiveness,” according to ProPublica. “Each of those studies (in 1996, 2012, 2014 and 2015) concluded that SCAN failed to help discriminate between truthful and fabricated statements.”
The 2016 study asked SCAN-trained raters to evaluate 234 statements. There was no consensus regarding the truthfulness of the written statements. In fact, the results would have been the same if the evaluation method was flipping a coin.
The authors wrote there is no evidence to support that the method works. “We discourage the application of SCAN in its current form,” the authors concluded.