Factor structure of the Millon Clinical Multiaxial Inventory (MCMI) with an offender sample

Area of Science:

• Psychological assessment
• Forensic psychology
• Clinical psychology

Background:

• The Millon Clinical Multiaxial Inventory (MCMI) is a widely used psychological assessment tool.
• Understanding the psychological profiles of offender populations is crucial for effective rehabilitation and management.
• Previous factor analyses of the MCMI have been conducted on diverse populations, but less is known about its structure within correctional settings.

Purpose of the Study:

• To conduct a principal components factor analysis of the Millon Clinical Multiaxial Inventory (MCMI) in a large sample of incarcerated individuals.
• To identify the underlying factor structure of the MCMI within a midwestern offender population.
• To determine if the MCMI factor structure in offenders is comparable to that found in other clinical and non-clinical groups.

Main Methods:

• A sample of 1,200 inmates was administered the Millon Clinical Multiaxial Inventory (MCMI).
• The sample was randomly divided into two groups of 600 for analysis.
• Principal components factor analysis was employed to examine the MCMI's factor structure in both groups.

Main Results:

• Four distinct factors were consistently derived from the MCMI data in both randomly divided groups.
• The factor structure demonstrated successful cross-validation between the two groups.
• Three of the identified factors showed similarity to factors reported in studies of drug abusers, psychiatric patients, and Vietnam veterans.
• A fourth factor emerged as unique to the offender population studied.

Conclusions:

• The Millon Clinical Multiaxial Inventory (MCMI) exhibits a robust and cross-validated factor structure within an offender population.
• The findings suggest that while some MCMI factors are generalizable across different populations, a unique factor is specific to individuals within the criminal justice system.
• This unique factor may represent specific psychological constructs relevant to offending behavior, warranting further investigation.