Many people see the lie detector test as controversial and intrusive.
There are also those in favor of the lie detector test who say that it is impossible to tell whether someone is lying or not or if someone is engaging his/herself in deceptive behavior.
Professionals involved in this science do not like to use the term lie detector, and would rather use polygraph.
A polygraph machine monitors the levels of many different bodily functions (heart rate, perspiration, etc.
The person judging the test looks at the answers given and the body's reaction to the questions to determine if the subject is engaging in deceptive behaviors.
The machine was once an analog machine that would scribble lines on graph paper as the paper scrolled automatically, and now it is digital.
What Does It Do? The polygraph detector measures the respiratory rate, the heart rate, and the amount of perspiration on the finger tips of the subject.
The examiner will assess the results of the test and study any differences in spikes and results of the behavior.
The subject in question is hooked up with wires and tubes to the lie detector machine.
The professional examiner will first get to know his/her subject and the subject's version of the story.
The lie detector is not used at this part of the testing process.
The examiner uses his/her own observation to record and monitor how the subject responds.
The next step is a list of specially designed questions created by the examiner.
He/she reviews these questions with the subject prior to turning on the lie detector test.
The actual lie detector test will be about 60-70% control questions, which are general questions many people have trouble answering "no" too.
The other 30-40% will be questions related directly to the situation at hand.
The test is considered an exact science by those who are well-trained in its processes.
These "scientists" take into account the subject's cultural background, religious beliefs, etc.
, and will only ask questions that will elicit "true" biological responses on the lie detector machine.
Controversy The men and women who argue against the lie detector test state that there are both false positives and false negatives with the test.
A false positive is where someone tells the truth, but it reads as a lie, and a false negative is where someone lies and it reads as the truth.
Some believe there is a way for someone to beat the machine by doing something such as biting their lip each tip a question is posed.
This elicits the same bodily reaction each time.
One of the biggest noted problems with polygraph tests is the inconsistency in the professional examiners.
There are states that allow virtually anyone to become a polygraph examiner, while other states require extensive, on-going training and certification.
Until all of these issues surrounding the polygraph test are resolved, there will be controversy regarding its practice, validity, and its use in the courtroom.