By Gerald Cooke, Psychologist

Child custody evaluations conducted by psychologists typically include personality testing of each of the parents, and sometimes also of significant others. While personality tests do not bear directly on parenting capacity, these tests often provide important information about personality traits which, along with other data, may be relevant to assessing parenting capacity. For example, these tests can provide information of whether a parent is experiencing interfering or disabling degrees of anxiety or depression, whether there is an anger management or other impulse control problem, or whether the individual has any impairment in the ability to respond to the needs and feelings of others, including children.

One of the most widely used personality tests is the Minnesota Multiphasic Personality Inventory-2 (MMPI-2). It is distributed by NCS Pearson Inc. (Copyright 2001, The Regents of the University of Minnesota). The current version of the test has nine validity scales, ten clinical scales, and numerous additional and experimental scales. If three of the validity scales: L, K, and S are significantly elevated this may indicate that the individual taking the test had a defensive test taking attitude. There has been controversy over how to interpret elevated defensiveness scales for custody litigants, including whether to attribute to the individual the personality characteristics associated with L, K, and S Scale evaluations. While the MMPI-2 manual states “Moderate elevations (T=70 to 79) on L are common in custody litigants and do not necessarily indicate an invalid profile”, other interpretive guidelines in the manual and various texts indicate that profiles with L Scale scores over 70, K Scale scores over 65, or S Scale scores over 70 may be invalid.

Comprehensive custody evaluations are often lengthy and expensive, particularly if there are several children and adult significant others. Often only those families with significant financial assets, usually associated with higher educational and occupational levels, are in a position to afford such evaluations. Research demonstrates that individuals having higher levels of formal education score higher on the K Scale and, by implication, also on the S Scale, as it is highly correlated to the K Scale. It is less clear whether the L Scale is affected by educational level.

The present author conducted a research study to determine the degree to which educational/socioeconomic factors affect custody litigants’ responses to the MMPI-2, and how this should impact on the personality interpretations as described in the manual, and in the research and clinical literature for elevations on these scales. That is, if a certain level of elevation is typical of more highly educated/higher socioeconomic level custody litigants, then the personality characteristics typically associated with these scales should not be attributed to them. This is important because many of these characteristics, such as rigid thinking or a lack of insight can have important implications for parenting (the full study is titled “MMPI-2 Defensiveness in Child Custody Evaluations: The Role of Education and Socioeconomic Level.” It is published in the American Journal of Forensic Psychology, Volume 28, Issue 2, 2010, pages 5 to 16). What follows is a summary of the findings. Those who are interested in greater detail regarding the study and its implications are referred to the journal article.

In the standardization sample for the MMPI-2 49.4% of the males and 42.2% of the females were college graduates and/or had post college graduate training. In the present study the comparable figure was 76% for both males and females. In addition, 28% of the males and 20% of the females in the present study had 19 or more years of education reflecting law, medical, doctoral, and post doctoral degrees.

Prior studies of custody litigants whose education approximated the standardization sample had mean T scores for the L Scale for males averaging 57.8 and for females averaging 58.6. In the current author’s study, the mean L Scale for males was 62.0 and for females 60.6. While this is not statistically significant because of large standard deviations, it does show a tendency for higher L scale scores in the higher educational/socioeconomic group. While L has not been clearly demonstrated to be related to education, it may be that for these more affluent custody litigants there is more to lose financially depending on the outcome of the custody case, and that may be a contributor to the increased L Scale scores. K Scale scores for males in prior studies averaged 56.6 and for females 58.1. By contrast, K scores in the present study were much higher: Males 62.4 and females 62.0. S scores in prior studies averaged for males 59.6 and for females 59.7. By contrast, mean S scores in the present study for males was 63.5 and for females was 61.5.

What this means for family lawyers is that when the custody litigant is of higher educational/socioeconomic level (particularly college graduate or above) the psychologist who did the evaluation should not describe the individual as having a defensive test taking attitude, or consider that the test is invalid, or attribute the personality characteristics typically associated with such elevations, unless the scores are at least one standard deviation above these means. K and S scores particularly seem to be a function of greater academic and occupational success. For this group a K Scale T score of less than 69.1 for males and less than 72.1 for females is within one standard deviation of the norm. For the S Scale, scores of less than 72.3 for males and less than 70.2 for females are within one standard deviation. For the L Scale, scores for males lower than 72.1 and for females lower than 71.5 are within the standard deviation. If the testifying psychologist uses the traditional interpretation of defensiveness, labels the MMPI invalid due to defensiveness, or attributes certain personality characteristics for these elevations (such as rigidity or lack of insight), then cross examination based on these research findings may be effective in demonstrating that the elevations are associated with academic and occupational success, and not these negative factors.


Dr. Gerald Cooke received his Ph.D. in clinical psychology in 1966.  He specializes in Forensic Psychology and is Board Certified in that and in Forensic Neuropsychology.  He has numerous publications in professional journals and books.  He has held a number of past teaching positions including Villanova University Law School. Dr. Cooke’s private practice is limited to forensic psychology and includes evaluations in child custody, criminal and personal injury cases, as well as consultation with police departments.