Lie detector tests -- or polygraphs -- are administered to an estimated one million people a year, according to Paul Ekman, a psychologist from the University of California at San Francisco.

The top reasons for giving these tests include:

Pre-employment screening, particularly by banks, retail operations and security firms.

Control of internal crime.

Screening for promotions, especially when they involve a higher security clearance.

Among those whom Ekman says rely upon this type of screening are members of the National Association of Drug Stores and the National Association of Convenience Stores, Brinks Inc. and Associated Grocers.

Requiring employes to take polygraph tests is legal in 33 states, Ekman says.

The federal government is the "third largest user of the polygraph test to detect lying," he says. In 1982, some 22,000 tests "were reported by various federal agencies." Most were given to either investigate crimes or for intelligence or counterintelligence purposes.

Federal agencies that use polygraph tests include: U.S. Army Criminal Investigation Command; U.S. Army Intelligence and Security Command; Naval Investigative Service; Air Force Office of Special Investigations; U.S. Marine Corps Criminal Investigation Division; National Security Agency; Secret Service; FBI; Postal Inspector Service; Alcohol, Tobacco and Firearms Administration; Drug Enforcement Administration; CIA; U.S. Marshalls; Custom Service and the Department of Labor.