Phallometry is the measurement of sexual preferences in sex offenders. The measurement involves recording the erectile responses of offenders to various sexual stimuli, thus establishing their sexual preferences. Behavioral therapy models, such as cognitive-behavioral therapy, rely heavily upon the use of phallometry in order to target and then modify deviant sexual preferences. Reviewing the reliance on phallmetry, the authors assert that the reliability of phallometric assessment has not been satisfactorily demonstrated. Considerable inconsistencies across studies with convicted rapists call into question the usefulness of phallometry assessment as an indicator of sexual preference and as a basis for treatment. The authors question whether the modification of sexual preferences is even necessary or useful in the treatment of sexual deviance. Several studies are reviewed that show no difference between pre- and post-treatment phallometric results. Moreover, the authors contend that some studies have revealed only marginal differences in phallometric results between offenders and non-offending males. As such, the authors conclude that behavioral therapies that attempt to modify deviant sexual preferences are not supported by the research literature. References