Insignificant Findings: Polygraph Testing for Youth Sexual Offenders

Background: A chasm has developed between proponents and opponents of post-conviction polygraph testing for youth sexual offenders. Professionals argue on issues related to validity, accuracy, habituation, ethics, deterrent effects, or recidivism predictions. Adult sexual offenders have specifically reported the polygraph to be a useful mechanism for avoiding relapse. With indiscriminate differences between adults and juveniles on the level of deceit, but with only personal accounts of the promise of the approach, the overall utility of the polygraph is called into question. Research has yet to reveal the association, or lack of association between the use of post-conviction polygraph testing and short-term or long-term outcomes for juveniles. This study sought to test associations between frequency of polygraph testing and outcomes of those tests as they relate to treatment completion and 1-year, 3-year, and 5-year recidivism outcomes.

Methods: This study was conducted in collaboration with a western state sex offender management board. A research team reviewed probation files of youth adjudicated of a sexual crime (N=85) between the years 1998-1999 (Group 1) and 2006-2007 (Group 2). The Office of Research and Statistics furnished recidivism data post-discharge. Data on polygraph testing included the frequency with which youth received the test (0-8 times post conviction) and the results from the tests including significant reaction indicated (0=No; 1=Yes), no significant reaction indicated (0=No; 1=Yes), and disclosure (0=No; 1=Yes). Data was gathered on treatment success (0=No; 1=Yes) and any sexual or non-sexual post-termination re-offense at 1-year, 3-year, and 5-year intervals (0=No; 1=Yes). Sexual and non-sexual recidivism were not separated, as base rates for sexual re-offending are low. Bivariate statistics including chi-squares and Pearson correlations were used to determine group differences and associations.

Results: There were statistically significant differences between the two fiscal year groups and the number of polygraphs they received, Χ²= 28.0, p<.001. The results also reveal that a non-significant reaction is associated with treatment completion, (r=.29, p<.05). There were no statistically significant associations between treatment completion and the number of polygraphs (r=.17, ns), significant interactions (r=-07, ns), or disclosures (r=.004, ns). There were no statistically significant associations between 1-year recidivism and number of polygraphs (r=-.18, ns), significant reaction (r=-.17, ns), non-significant reaction (r=-.17, ns), or disclosure (r=-.01, ns). There were no statistically significant associations between 3-year recidivism and the number of polygraphs (r=.23, ns), significant reaction (r=.11, ns), non-significant reaction (r=.24, ns), or disclosure (r=-.04, ns). Finally, there were no statistically significant associations between 5-year recidivism and the number of polygraphs (r=-.03, ns), significant reaction (r=-.03, ns), non-significant reaction (r=-.13, ns), or disclosure (r=-.27, ns).

Implications: This study suggests that while polygraph testing may have some short-term impacts on treatment completion, it may not lead to long-term behavior change. Overall, polygraph testing has limited evidence and may not support risk prediction or reduction. It may instead be an antiquated practice used, maybe unintentionally, to elicit confessions.  Empirical research using randomized trials is needed to test the effectiveness of post-conviction polygraph tests.