Computers

Courtroom fibs used to develop lie-detecting software

Courtroom fibs used to develop...
If you want to find liars, this is a good place to look
If you want to find liars, this is a good place to look
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If you want to find liars, this is a good place to look
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If you want to find liars, this is a good place to look

There's a challenge when you're developing new lie-detection software – you can get people to lie for you in a lab setting, but their behaviour won't be the same as it would be in a real-world scenario. In order to see authentic lying behaviour, you need to go somewhere where the stakes for the liars are higher. That's why scientists from the University of Michigan turned to videos of courtroom testimonies.

Led by professors Rada Mihalcea and Mihai Burzo, the researchers used machine-learning techniques to analyze 120 video clips of actual trials. Based on the outcome of those trials, they knew which witnesses were (presumably) lying when they were on the stand.

It was determined that among other things, liars were more likely to scowl/grimace, look directly at their questioner, gesture with both hands, use filler words such as "um," and use phrases that reflect certainty on their part.

Running algorithms based on that data, the software subsequently analyzed videos of people, half of whom were lying and half of whom were telling the truth. It was able to identify the liars with 75 percent accuracy, which was considerably better than the 50 percent managed by human test subjects.

It is hoped that once developed further, the software could become an effective lie-detection tool in fields such as law, security and mental health. Unlike conventional polygraphs, it wouldn't need to physically touch the people it was assessing, allowing for a wider range of uses.

Source: University of Michigan

5 comments
piperTom
The liars will "scowl/grimace, look directly at their questioner," et al. That's for novice liars. They should look at the pros, too. Best (and easiest) example is poker players, but don't overlook politicians.
Nik
For best liar subjects, just record campaigning politicians, the higher their political standing, and experience, the more glibly they lie.
drender
75%???? That's a terrible hit rate. Imagine if your car worked 75% of the time. It's terrifying to think that someone could be convicted, or not given a job, etc. based on results from the incorrect 25%.
Tjoe
If they have a computer that can tell lies, all the judges and attorneys will be in trouble. The DOJ has made lying in court okay under the policy of "alternative defenses", so what good would a device be? Judges and attorneys are masters of the un-truth.
mdr
".....the 50 percent managed by human test subjects." Did they just flip a coin to determine who lied?