situations, and O’Hair and Cody (1987) found voice stress analyses to be unsuccessful in detecting spontaneous lies in a simulated job interview. Voice stress analysis may be more successful in detecting real crimes or other nontrivial deceptions, when the level of stress is presumably higher, but even in these cases the evidence of accuracy is rather slim.
During the 1990s, the U.S. Department of Defense Polygraph Institute (DoDPI) carried out a series of laboratory tests comparing the use of the computer voice stress analyzer and the polygraph using peak of tension and control question test formats. Cestaro and Dollins (1994) used a peak of tension test to compare with the analyzer in a standard laboratory comparison, and Cestaro (1996) and Janniro and Cestaro (1996) carried out comparisons with control question test formats for mock crime scenarios. These studies, which suffer from the same methodological deficiencies as most polygraph research, found that the computer voice stress analyzer was never significantly superior in its detection accuracy to the polygraph and that neither had exceptionally high correct detection rates. Palmatier (1996) conducted the only field test comparison, in collaboration with the Michigan Department of Police, using confirmed guilty and a group of presumably truthful examinees. Again, the analyzer results were close to chance levels (polygraph results were not reported). The detailed administration of the analyzer tests was severely criticized by the NITV, and the details of these criticisms are appended to the report. The most recently completed DoDPI study (Meyerhoff et al., 2000) compared the computer voice stress analyzer with biochemical and direct physiological measures of stress and concluded that the analyzer scores did not reflect the acute stress observed by more traditional stress measurements.
Overall, this research and the few controlled tests conducted over the past decade offer little or no scientific basis for the use of the computer voice stress analyzer or similar voice measurement instruments as an alternative to the polygraph for the detection of deception. The practical performance of voice stress analysis for detecting deception has not been impressive. It is possible that research conducted in high-stakes situations would give better results, but we have not found reports of the accuracy of voice stress analysis in such situations.
Handwriting analysis, or graphology, is sometimes used to make inferences about honesty, integrity, or dependability. The underlying theory is that various characteristics of a person’s handwriting provide information about his or her personality, including such traits as honesty or loyalty. Although there are serious questions regarding the validity of