President Reagan's recent polygraph directive is expected to help deter spying against the US and also establish a disincentive for government workers prone to leak classified information to the press. This directive revives the debate concerning mandatory polygraph tests. Their use has long been a controversial issue because of uncertainty about their accuracy and fears that innocent careers could be tainted by an inaccurate machine or an inexperienced operator.
The directive, issued Nov. 1 and announced Wednesday, provides for the wider use of polygraph tests among ``a selective number of officials who have the highest levels of access to classified information,'' according to White House spokesman Larry Speakes. Estimates are that several thousand federal employees will be required to take such tests.
Officials of the executive branch, including the Defense, State, Energy, and Justice Departments, will be required to submit to random polygraph tests to gain access to highly classified US documents. The tests would require government workers to answer whether they have ever passed classified documents to persons not authorized to receive them.
Polygraph exams are already routinely conducted for employees of the Central Intelligence Agency, the National Security Agency, and for some employees at the Defense Department.
Proponents of the wider use of polygraphs maintain that the polygraph test is but one of an array of investigative tools to be used in weeding out potential security risks among government workers.
In a joint statement, the chairman and vice-chairman of the Senate Intelligence Committee urged caution in the implementation of the polygraph directive.
``Senior executive-branch officials have expressed divergent views on the desirability of such a polygraph program,'' said Sens. Dave Durenberger (R) of Minnesota and Patrick J. Leahy (D) of Vermont. They added that ``any such program should have the most stringent quality controls to prevent mistakes that would jeopardize national security or the reputations and careers of individuals.''
The administration made a similar proposal for the wider use of the so-called lie detectors in 1984, but dropped the plan following press and congressional criticism during the President's reelection campaign.
The new proposal comes following an unprecedented string of espionage cases in United States courts, including prosecution of the Walker family spy ring and the uncovering of alleged individual spies for the Soviets, the Chinese, and the Israelis.
Officials have said that while polygraphs may help deter some Americans from spying, they may not faze trained professionals. There have been reports that the Soviets are able to teach their spies and operatives to beat a polygraph.
Others maintain that even if the machines are 95 percent accurate, as proponents claim, there is still a 5 percent margin for error. Under these conditions, if 1,000 employees were tested, the results of 50 tests would be inaccurate. In such cases, the machine would have either falsely accused a loyal employee of lying, or granted safe passage to a spy by indicating he or she answered truthfully when the spy was actually lying.
Experts stress that polygraph machines are not able to actually detect lies. They say polygraphs simply monitor the physiological responses of people while they answer a battery of questions. A rapid change in a subject's physiological responses registers on three graphs. This rapid change is usually interpreted by trained polygraph operators as indicating that the subject is being deceptive.
Opponents of polygraphs maintain that the machines measure anxiety. They argue that habitual liars or people who harbor no fear about the potential accuracy of the machine will register no response and pass their tests.
According to officials who have taken such tests, when a reaction is observed, the machine is turned off and government interrogators challenge the veracity of the subject's statements, seeking a confession.
Officials say polygraph-induced confessions have often proved more valuable to security personnel than the test itself.