Date of Award


Document Type

Doctoral Research Project

Degree Name

Doctor of Psychology (PsyD)



First Advisor

Radhika Krishnamurthy, Psy.D., ABAP

Second Advisor

Mary Caitlin Fertitta, Psy.D.

Third Advisor

Travis Conradt, Ph.D.

Fourth Advisor

Robert A. Taylor, Ph.D.


Clinical evaluations have had a long-standing role in criminal and civil legal proceedings due to the intersection between various legal criteria and aspects of psychological functioning. The Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) and its subsequent versions have been among the most commonly utilized and empirically supported measures of personality and psychopathology in assessing forensic populations. One application for which MMPI instruments have been particularly useful is in the evaluation of sex offenders. This is in part due to the tests’ built-in validity scales, as MMPI underreporting scales are found to be effective in assessing sex offenders’ tendency to deny personal faults and/or psychological maladjustment. Defensiveness is also evident in other populations that undergo high-stakes evaluations, such as child custody litigants. However, whether the type of defensiveness across sex offenders and child custody litigants is similar in nature remains undetermined. The current study therefore compared defensiveness on the MMPI-2-RF in a sample of male sex offenders (N = 268) and child custody litigants (N = 260), both representing presumed defensive groups, by evaluating if test scores and item responses distinguish between these groups. Differences were also examined between clearly defensive subgroups of the sex offender (N = 102) and child custody litigant (N = 168) samples, defined as elevating one or both underreporting validity scales. Results of t-test analyses for the presumed defensive samples comparison revealed child custody litigants were higher on the validity scale measuring denial of maladjustment (K-r), while sex offenders scored higher on overreporting of rare symptomology (F-r). On the clinical scales, multivariate analyses of variance (MANOVAs) and subsequent univariate analyses of variance (ANOVAs) revealed that, while both groups produced generally average range profiles, sex offenders scored significantly higher than custody litigants on 36 of 40 clinical scales. Item-level analysis results supplemented scale-level findings in identifying specific areas of difference. Results from the validity scale analysis for the clearly defensive groups revealed similar results to those of the presumed defensive comparison, with the addition of clearly defensive sex offenders scoring significantly higher than child custody litigants on the validity scale measuring denial of common faults (L-r). There were fewer areas of difference between clearly defensive sex offenders and custody litigants on the clinical scales than in the presumed defensive samples, but the direction of differences remained largely the same with sex offenders producing higher scores and item endorsement rates. Overall, findings indicated that sex offenders and custody litigants differ somewhat in the nature and degree of MMPI-related defensiveness, with sex offenders demonstrating denial of behavioral dysfunction and custody litigants demonstrating denial of certain undesirable interpersonal characteristics, and with child custody litigants consistently producing more defensive profiles. This study identified important implications for forensic practice, which were discussed.