Incremental Validity of the Multidimensional Personality Questionnaire in the Preemployment Assessment of Police Officer Candidates

• Author: David M. Corey,Yossef S. Ben-Porath,Martin Sellbom
• DOI: 10.1177/00938548211033630
• Published date: 01 July 2022
• Date: 01 July 2022
• Subject Matter: Articles

CRIMINAL JUSTICE AND BEHAVIOR, 2022, Vol. 49, No. 7, July 2022, 1050 –1069.

DOI: https://doi.org/10.1177/00938548211033630

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© 2021 International Association for Correctional and Forensic Psychology

1050

INCREMENTAL VALIDITY OF THE

MULTIDIMENSIONAL PERSONALITY

QUESTIONNAIRE IN THE PREEMPLOYMENT

ASSESSMENT OF POLICE OFFICER

CANDIDATES

MARTIN SELLBOM

University of Otago

DAVID M. COREY

Corey & Stewart

YOSSEF S. BEN-PORATH

Kent State University

Guidelines for screening public safety personnel candidates, including law enforcement positions, incorporate the use of

separate psychological tests for assessing normal and abnormal functioning. We evaluated the incremental validity of the

Multidimensional Personality Questionnaire (MPQ)—a measure of normal personality traits—beyond the Minnesota

Multiphasic Personality Inventory–2 Restructured Form (MMPI-2-RF), a measure of psychopathology, using a sample of

1,687 candidates for law enforcement positions. They were clinically rated on 10 psychological suitability dimensions. For

a subset of those who were subsequently hired as police officers (n = 397), we also had post-hire outcome data. Using hier-

archical nonlinear regression analyses, we found that the MPQ scales incremented the MMPI-2-RF scales in the prediction

of 17 of 19 variables in this study. Our results indicate that the MPQ, as a measure of normal personality, provides unique

information about psychological suitability and predicts negative post-hire outcomes in police candidates.

Keywords: Multidimensional Personality Questionnaire; Minnesota Multiphasic Personality Inventory; preemployment

screening; law enforcement; police; predictive validity

Assessing the psychological suitability of law enforcement officer candidates contrib-

utes to an important societal goal of ensuring that police officers, at least at the start

of their career, are free of job-relevant psychopathology and personality problems—a

goal incorporated into law in most jurisdictions (Corey & Borum, 2013). In the United

States, the most common psychological test battery used for conducting preemployment

AUTHORS’ NOTE: This research was supported by a grant from the University of Minnesota Press, publisher

of the Multidimensional Personality Questionnaire and the Minnesota Multiphasic Personality Inventory–2

Restructured Form (MMPI-2-RF). Martin Sellbom and Yossef Ben-Porath are paid consultants to the University

of Minnesota Press. David Corey and Yossef Ben-Porath are authors of the MMPI-2-RF Police Candidate

Interpretive Report (PCIR) and receive royalties on the sale of the report. Yossef Ben-Porath is a coauthor of

the MMPI-2-RF and he receives royalties on sales of this test. Correspondence concerning this article should

be addressed to Martin Sellbom, Department of Psychology, University of Otago, PO Box 56, Dunedin 9054,

New Zealand; e-mail: martin.sellbom@otago.ac.nz.

1033630CJBXXX10.1177/00938548211033630Criminal Justice and BehaviorSellbom et al. / Incremental Validity of the MPQ

research-article2021

Sellbom et al. / INCREMENTAL VALIDITY OF THE MPQ 1051

psychological evaluations of law enforcement officer candidates—indeed, the method

required by many jurisdictions and considered the “basic model” of psychological screening

of police candidates (Corey & Ben-Porath, 2018; Serafino, 2010)—involves the use of two

assessment instruments validated for use with both the general population and police candi-

dates: one measuring a range of normal personality traits and the other a broadband measure

of psychopathology and abnormal functioning. The implied rationale for using two such

measures is that they provide complementary information about candidates’ suitability.

Determining the job relevance of findings from preemployment psychological assess-

ments of police officer candidates first requires knowing the jurisdiction’s “criterion stan-

dard” for the position (American Psychological Association, 2018), namely, the “statutory,

regulatory, or administrative standard by which the suitability of a candidate . . . is assessed”

(Corey & Zelig, 2020, p. xix). The most commonly used and detailed criterion standard for

assessing police candidates, either alone or in combination with a broader statutory crite-

rion,1 are the 10 Psychological Screening Dimensions promulgated into law by the California

Commission on Peace Officer Standards and Training (POST; 11 California Code of

Regulations § 1955(d)(2)). The 10 POST Psychological Screening (POST-10) Dimensions

and broad descriptions of their content are included in the Online Supplemental Materials

(Table S1). See Spilberg and Corey (2020) for a complete description of the method used

for validating the POST-10 criterion standard.

With respect to specific psychological tests, there exists a substantial body of peer-

reviewed literature documenting the validity of the Minnesota Multiphasic Personality

Inventory–2 Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008/2011), a

broadband measure of personality problems and psychopathology, in using preemployment

test results of police candidates to predict post-hire outcomes that are explicitly linked to the

POST-10 dimensions (e.g., Tarescavage, Corey, & Ben-Porath, 2015, 2016; Tarescavage,

Corey, Gupton, & Ben-Porath, 2015; Tarescavage, Fischler, et al., 2015). With regard to

normal personality tests, Sellbom et al. (2021) examined the validity of the Multidimensional

Personality Questionnaire2 (MPQ; Tellegen & Waller, 2008), which is the first study to

explicitly link a test of normal personality functioning to the POST-10 dimensions. Sellbom

et al.’s (2021) findings support the validity of the MPQ to predict psychologists’ ratings of

the POST-10 dimensions as well as job performance outcomes. The authors also explored

the MPQ’s broader construct validity with a large sample of police candidates and found a

conceptually expected pattern of associations with criterion variables, including biographi-

cal data, clinician ratings, and post-hire performance outcome data.

There exist very few peer-reviewed validation studies of commercially available mea-

sures of normal personality functioning demonstrating their utility in preemployment eval-

uations of police officer candidates. Although the California Psychological Inventory (CPI;

Gough & Bradley, 1996) is an exception in this regard (see, e.g., Roberts et al., 2019), three

considerations limit its utility for use in conjunction with the MMPI-2-RF (as well as with

the most recent version of the test, the MMPI-3; Ben-Porath & Tellegen, 2020). First, the

CPI technical manual (Gough & Bradley, 2002) does not list the items comprising each

scale, thereby precluding test users from identifying item overlap and, relatedly, pinpointing

the source of scale intercorrelations, and from evaluating the potential impact of item non-

responsiveness on the reliability of a scale score. Moreover, the substantial content (and

item) overlap and intercorrelations among CPI scales have been cited often as a factor limit-

ing empirical findings in research using this instrument (e.g., Bernstein et al., 1983; Carey