[The following is an exact transcript of this podcast.]
When we lie, our brains work hard to make sure we get the story right and come off as truthful. Law enforcement officials try to tap into that effort, for example with polygraphs, to find out if a suspect is telling the truth. But such stress tests are beatable and not admissible in court. Now comes a report that handwriting tests could be a competitor to the familiar, but unreliable lie detector. The study appears in the Journal of Applied Cognitive Psychology.
Researchers at Israel’s Haifa University worked with 34 volunteers, who wrote truthful and false paragraphs on paper using a wireless electronic pen and a pressure sensitive tip. A computerized system measured pressure and stroke duration, both on the paper and in the air. Spatial measures, such as stroke length, height and width were also tracked. And the scientists found significant differences in pressure and spatial measures in deceptive statements compared with the truth.
The investigators say they need to validate this initial result and compare the technique with polygraphs and other lie detection tools. But perhaps in the future even a written claim of innocence could turn out to be a de facto confession.