The polygraph instrument measures
CHANGES in a person's physiology during the course of the test. Nervousness is a generalized condition which exists
throughout the entire exam, not just on one or two questions. Because nervousness
exists during the entire test process, it will not affect the test score. Extreme
nervousness, however, may cause a person to fidget or not sit still during the
exam, and this could distort the test enough so that the results can not be analyzed. In
general, though, being nervous will not change a person's test results. Most
people are nervous when doing anything new for the first time.