A new experiment[1] has discovered an inexpensive, accurate method of lie detection from handwriting samples. The beauty of the procedure is that the electronic handwriting tablet and software are apparently readily available, technician training is under an hour, and the statistically significant results are almost impossible to fake. However, it is not perfect; results may be skewed by age, illiteracy or neurological, emotional or physical disease.

            Starting from the premise that fabrication requires more brain activity, the researchers at Haifa University in Israel, Gil Luria and Sara Rosenblum, compared temporal, spatial, and pressure characteristics of truthful and untruthful handwritten paragraphs. In false paragraphs, data indicated significantly greater:

                        Pressure of pen on paper;

                        Height of the characters (“stroke height”); and

                        Length of characters.

            The results are consistent with the experimenter’s premise that lying requires more thinking resources, leaving less attention available for committing the lie to paper.  When you are paying less attention to your handwriting, you create longer, higher letters and push down more on the paper.

            Reportedly, the significantly different appearance of true and false paragraphs cannot be consistently controlled by the person doing the writing, even if they try. And the authors posit that their results should hold true for any written language.

            I can foresee legislatures supplementing DNA testing with the handwriting pad. It might work like this: A suspect who was licensed to drive in the jurisdiction where he or she was stopped on suspicion of crime would have consented in advance — as a condition of licensure – to write out a paragraph about his last vacation (or some other banal, true subject) as well as a second paragraph detailing his or her alibi for the time of the crime. Software would score the handwriting on the spot to produce a “pass” or “fail”. Test failure would constitute probable cause for arrest.

            The Supreme Court of the United States might sanction this curtailment of Fifth Amendment Constitutional rights. It might rule that those wanting to preserve such rights could have opted not to obtain a driver license.

           



[1] Gil Luria, Sara Rosenblum. Comparing the handwriting behaviours of true and false writing with computerized handwriting measures. Applied Cognitive Psychology, 2009; n/a DOI: 10.1002/acp.1621.

© 2009 John Wiley & Sons, Ltd.