In a unanimous decision, the Supreme Court of South Carolina has ruled that penile plethysmography lacks sufficient scientific support to be used as a reliable indicator of likely future recidivism in sex offenders. Among its many flaws, the court cited a lack of standardized metrics among different labs, poor test-retest consistency, inconsistent test materials, and the variance in penile responsiveness depending on time of year, sex of the test administrator, and a test-subject’s cardio-vascular health, his degree of intoxication or fatigue, his ability to control his thoughts, and when he last experienced orgasm. All a subject needs to do to trick the machine is masturbate directly before testing. South Carolina joins the many other states that ban use of this intrusive and dehumanizing device in forensic applications. Although no more scientifically valid than the lie detector and the “fruit machine” that we featured in the last edition of Hard Copy, plethysmography nevertheless continues to be regarded as reliable by some sex researchers and featured in their published studies. The sooner this ghastly instrument is consigned to a museum of antique medical devices, the better. All scholarly studies using it should be retracted.
Penile Plethysmography Ruled Inadmissible
