Phallometric Testing

Phallometric testing using the penile plethysmograph involves the measurement of changes in penile circumference in response to sexual and nonsexual stimuli. It provides objective information about male sexual interests, and is therefore useful for identifying deviant sexual interests. (ATSA Practice Standards and Guidelines)

This test was developed by Kurt Freund in the 1950s and 1960s originally to assess sexual or erotic preferences for children versus adults and males versus females, but it has been extended by other researchers to examine other sexual disorders, including a preference for sexual aggression. Repeated assessments can be helpful to monitor treatment progress, and to provide information for risk management purposes. The phallometric testing report includes a description of the method used for collecting data, the types of stimuli used, an account of the client’s cooperation and behaviour during testing, and a summary and description of the client’s profile of responses. Efforts to fake or other potential problems for the validity of the data or the interpretation of results are also reported. My training in phallometric testing is with Dr. Ron Langevin who handed over his laboratory to me.

Phallometric test measures sexual arousal to both appropriate (age appropriate and consenting) and deviant sexual stimulus material. Stimuli can be audio, visual, or a combination. However, Phallometric testing results should not be used to make inferences about whether an individual has or has not committed a specific sexual crime. It should not be used as the sole criterion for estimating risk for engaging in sexually abusive behaviour. Phallometric Testing results should be correlated with clinical impression and psychological testing. Therefore, the results are in conjunction with other relevant information (for example, the individual’s offending behaviour, use of fantasy, and pattern of masturbation) to determine risk and treatment needs.

Generally, this test is recognized as the best objective quantifiable measure of male sexual arousal because blood flow into the penis is the only measure of sexual arousal that doesn’t seem to be influenced by other factors. The objective ability to measure penile arousal has helped it to evolve into one of the important tests in the assessment and treatment of male sex offenders.