Wed | Jul 26, 2017

Polygraph is junk science

Published:Friday | April 23, 2010 | 4:00 AM

The Editor, Sir:

I noticed from recent articles posted on the Internet that there are proposals to conduct polygraph examinations of police and government employees to deter corruption. Although the goal is commendable and achievable, the selection of the polygraph is not a good choice.

The polygraph has failed miserably in the United States (US) and Mexico, and has an error rate in excess of 35 per cent. This means there is a very significant chance that an innocent person may appear to be guilty based on the polygraph (this is referred to as a False Positive result).

There has been a concerted effort by the polygraph industry to embellish both the accuracy and utility of the polygraph. In a report prepared for the US Congress, the National Academy of Sciences stated that "Bias, conflict of interest, and unscientific decision making" was evident in the so-called 'studies' that were produced by the polygraph industry to support their claims of accuracy.

Extremely inaccurate

The proponents of the polygraph never mentioned the vast amount of evidence showing the polygraph to be extremely inaccurate, and that the polygraph has a 50-year documented history of convicting innocent people of crimes they did not commit. Also, according to the US National Academy of Sciences, the polygraph is no better than the flip of a coin when conducting 'screening' examinations, such as attempting to identify those involved in corruption.

I believe that both your citizens and government officials should be made aware of this information before disastrous mistakes are made by relying on the 'junk science' of polygraph. The polygraph has ruined the lives of many innocent people, and it would be tragic if this were allowed to happen in your nation.

I am, etc.,

Professor JAMES L. CHAPMAN

jchapman@stnv.rr.com

Criminologist