The search for truth is the driving force that causes every scientific endeavor to progress. This establishes the connection between truth and science. But telling the truth may deviate from what is scientifically acceptable. It is because in some cases, truth is relative. Its veracity depends on certain factors such as integrity and motivation. That is why, it is very important that there should be a truth detector. But science has provided us with one —- the lie detector test.
The lie detector test is the only scientific approach in determining a deceptive statement. It is the only resort to investigators, after all effort failed to establish connection gaps in information, hoping to force something straight from the horse’s mouth. But how reliable is the lie detector test? How effective and accepted is it? Let the numbers show.
Reliability has something to do with consistency. The reliability of the polygraph test points to how consistent or accurate it is in determining deception based on the psychophysiological changes recorded by the instrument itself. The reliability of the polygraph test is a few percent short of 100% reliability. The reliability index is from 0.95 to 0.98, which translates to 95% to 98% accuracy. The index may be high but when talking about the truth, anything that is less than 100% true is a lie. However, the accuracy index should not be interpreted that way. This index might have been taken from collective and generalized findings.
But courts would not risk their decisions and allow admission of a polygraph test as an evidence with this percentage of accuracy polygraph can offer. The courts demand that everything presented to them is 100% true — nothing less than it.
Extent of Use
The effectivity of polygraph test as an esteemed instrument for whatever purpose is determined by its continued use. We need research data here. The APA Research Center at the Michigan State University conducted a survey involving 699 police executives from all over the United States to determine the extent of and conditions in which polygraph testing is being used. Results showed that 62% of these executives had active polygraph screening program in their respective police agencies, 31% did not have active polygraph testing program, and 7% ceased to operate with the program. These figures translate to the respondents’ confidence in using polygraph testing the whatever end they thought it was necessary.
Gavin Wilson, an Australian police officer who had his polygraph testing training in the US, believe that the polygraph test is still relevant and useful for the Australian police. As a polygraph examiner, he said that the polygraph is 96 per cent accurate. However, he also disclosed that 3% of the composition of the polygraph test is inconclusive. The 3% inconclusive component pertain to those questions that do not contribute to the findings or results of the test and are influenced by extraneous variables such as the age of the subjects. However, he failed to identify these components of polygraph test.