Polygraphy: Instrumental Interrogation

• Polygraphy is instrumental interrogation, used as a scientific method of detecting deception.
• A polygraph is a machine used to aid in the detection of deception.
• Polygraph comes from the Greek words "Poly" meaning "many", and "Graph/Graphos" meaning "write".
• The term polygraph was coined by Thomas Jefferson.

Definition of Terms

• Deception is the act of deceiving or misleading, usually with lying.
• Lying is uttering or conveying falsehood to create a false or misleading impression.
• The goal of lying is to affect something wrongfully.
• Truth is the body of real things, events, and facts.
• A lie is a type of deception in the form of an untruthful statement, with the intention to deceive.
• A liar is a person who is lying, has previously lied, or tends by nature to lie repeatedly, even when not necessary.

Kinds of Lies

• A jocular lie is deceit for the purpose of lying.
• A white lie/judicial (officious) lie is a harmless lie.
• An emergency lie is a strategic lie told when the truth may not be told.
• A malicious lie is intended to obstruct justice.
• A red lie destroys ideologies by means of propaganda.
• A big lie is an attempt to trick the victim into believing something major, likely construed by information the victim already knows or possess.
• A black lie is intriguing to cause dishonor or discredit one's good image.
• A puffery lie/promotion lie is used for advertisement or promotion.
• Lying by omission involves omitting an important fact.
• A lie of compliment or false reassurance is used to please others.
• Perjury is committed when a person is under oath or affirmation.
• Fabrication is submitting a statement as truth without knowing whether it's true or not.

Types of Liars

• Professional liars.
• Pathological liars.
• Hindu books, like Ayur Vida from around 500 BC, were used as references for detecting deception.
• Other books included Dharmasastra of Gautama, and Vasistha of Dharmasastra.

Early Methods of Detecting Deception

• Ordeal is the oldest form of crime detection, subjecting the subject to an obstacle or trial.
• Types of ordeals include ordeal by combat, red hot iron ordeal, boiling water ordeal, rice chewing ordeal, and ordeal by balance.

Uses of Polygraph Testing

• Polygraph testing is used in criminal investigations, employment and security screening, and clinical settings.

Criminal Investigation

• The goal is to verify statements of witnesse, suspects, or victims.
• To determine the involvement of one person in a crime.
• To expedite the investigation process.
• To eliminate wrongfully accused individuals and identify the guilty party.

Employment and Security Screening

• The purpose is to determine if an applicant is truthful on their application.
• Questions usually focus on employment history, credits, driving, drug and alcohol use, falsification of information, criminal activities and associations.

Early Scientific Methods of Detecting Deception

• Word Association Tests
• Hypnotism
• Use of alcoholic beverages
• Truth serum
• Polygraph

Criminal Investigation applications of Polygraphy

• Diagnostic application.
• Interrogation application.

Clinical Testing types

• Disclosure
• Maintenance
• Specific