How A Polygraph Test Works

A polygraph is a three-part test that measures various physiological processes that can indicate whether a person is telling the truth about an event, experience, or past action.

Polygraph testing isn’t just for criminal investigations. There are many situations in which you can ask or be asked to take a polygraph test.

• Background checks
• Marital issues
• Family issues
• Employee theft
• Pre-employment testing
• Law Enforcement pre-employment examination
• Customs and border protection
• Post Conviction Sex Offender Testing
• Wrongfully accused

The accuracy of polygraph testing is a highly debated subject mostly because human reactions are not standardized. An honest person may act nervous while a deceptive person might maintain calm. There’s also little research that examines whether outside factors, like education or intelligence level, affect the test.

However, in 2002 the National Academy of Sciences conducted a comprehensive review that concluded polygraph testing to be better than chance even if it fell short of complete accuracy. Raymond Nelson, president of the American Polygraph Association, claims the accuracy rating is above 80%.

It’s common to be nervous while taking a polygraph exam. So we want to explain a little bit about what to expect in the exam.