We elect to use the Abel Screen, one because of the qualifications of Dr. Abel personally and two, for the fact that, as previously stated, the plethysmograph testing can easily be degrading to many. The penile plethysmograph measures penile circumference in millimeters caused by a partial or total erection. It is, therefore, a good, direct measure of physiological arousal because erection rarely occurs except to sexual stimulation. The Abel Screen, on the other hand is a reaction time measure, an indirect measure based on the belief that sexual arousal interferes with cognitive processing as measured by reaction time. These are two totally different methods of measuring a sexual preference, such as pedophilia.
Reaction time is difficult to fake.
Both the Abel Screen and the plethysmograph are very good tools and, in reality, each does pass all the requirements for scientific measure. The catch is that there are a few people who molest children who are not sexually aroused by children, such as psychopaths, alcoholics and child porn persons who are in it for the money, but they can usually be detected with psychological tests. Although not perfect, the accuracy of both of these devices are probably the best of any psychological tools. Doctor Abel is a Board Certified Psychiatrist and Medical Director. He is a distinguished psychiatrist with a national and international reputation for diagnosing and treating problems of sexual misconduct and sexual aggression.