Handwriting can reveal tell-tale signs of deception, according to a study published in the November issue of the journal Applied Cognitive Psychology. To see whether people’s handwriting differed when they were writing true or false statements, a team of researchers the from Faculty of Social Welfare and Health Sciences at Haifa University in Israel employed a complicated computer analysis program called the Computerized Penmanship Evaluation Tool (ComPET). They then had 34 subjects write true and false sentences on the tool’s “digitizer,” or electronic writing tablet, and measured all aspects of the penmanship—including the height and length of individual strokes, and the pressure applied while writing.
They found that, there were clear differences in all three of those measurements—average pressure applied, and length and height of individual strokes of the pen—when people were lying. Across the board, those three measurements were much higher when people were writing false statements—mean stroke length, for example, was 9.9mm when people were telling the truth, but 10.56mm when what they were writing was false. (In contrast, there were no differences in writing speed, for example.) The findings, researchers say, suggest that computerized handwriting analysis could be a valuable tool in lie detection in the future.
Additional studies are needed to confirm the efficacy of the ComPET system, yet the researchers are already speculating about possible uses for the technique in psychological research, and in non-academic settings as well. Perhaps, the researchers suggest, new lie detector tests could combine computerized handwriting analysis with polygraphs to achieve more accurate results.