HC Deb 08 December 1988 vol 143 cc268-9W
Mr. David Howell

To ask the Prime Minister what progress has been made in implementing the recommendation contained in the Security Commission's report on the case of Geoffrey Prime, Cmnd 8876, that there should be a pilot study to test the feasibility of polygraph security screening in the intelligence and security agencies; and if she will make a statement.

The Prime Minister

The first phase of the pilot study included the examination of staff of the security service and of senior staff of the Government Communications Headquarters (GCHQ). Following completion of that phase and before deciding on a starting date for the second phase, which was intended to cover the testing of a random sample of the staff of GCHQ, the Government commissioned a review of the scientific literature relating to the validity of the polygraph. This was conducted by Dr. A. B. Levey, a senior psychologist in the Medical Research Council. Dr. Levey delivered his report, which was based on an examination of 372 professional and scientific papers from which 100 were selected for a more detailed analysis earlier this year. I am placing a copy in the Library.

Dr. Levey's conclusion from the literature is that the polygraph is probably incapable of achieving a high level of accuracy and reliability when used for screening purposes and, moreover, that individuals trained in the use of counter-measures would have a good chance of escaping detection. Against this background the Government concluded that there would be no advantage in implementing the second phase of the pilot study, but before reaching a final decision, the Government felt it right to consult the Security Commission again.

The Security Commission has considered Dr. Levey's report and has taken further evidence from the director general of the security service and the director of GCHQ. In the light of their evidence the Security Commission accept that there would, in present circumstances, be no point in continuing the study. The commission believes, however, that the possibility of introducing the polygraph should not be ruled out for all time. In the light of the Security Commission's comments, the Government have decided that, while scientific research on the validity of the polygraph should continue to be monitored, the pilot study should not proceed further.

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