An evaluation of an MMPI response consistency measure

Area of Science:

• Psychological assessment
• Neuropsychology
• Psychopathology

Background:

• Assessing the validity of psychological test protocols is crucial for accurate diagnosis.
• Response inconsistency has been proposed as a potential indicator for invalidating MMPI protocols.
• Previous research has explored various methods for detecting invalid MMPI responses.

Purpose of the Study:

• To investigate response inconsistency as a potential index for invalidating Minnesota Multiphasic Personality Inventory (MMPI) protocols.
• To compare response inconsistency between brain-damaged and non-brain-damaged patient groups across different diagnostic categories.
• To examine the correlation between response inconsistency and established MMPI validity scales.

Main Methods:

• Measured response inconsistency using 14 pairs of identical items in 8 groups (n=22 each): brain-damaged/non-brain-damaged schizophrenic, alcoholic, neurotic, and normal patients.
• Correlated individual response inconsistency scores with standard MMPI validity measures (?), L, F, and K scales.
• Analyzed response consistency scores across all patient groups.

Main Results:

• All groups exhibited high overall response consistency.
• Brain-damaged patients demonstrated significantly higher response inconsistency compared to non-brain-damaged patients, irrespective of psychiatric diagnosis.
• Correlations between response inconsistency and MMPI validity scales were statistically significant but low in magnitude.

Conclusions:

• Response inconsistency is not a sufficiently sensitive or specific measure for invalidating MMPI protocols.
• Established MMPI validity scales (e.g., ?, L, F, K) remain the primary and most effective means for assessing protocol validity.
• Future research may explore refined methods for detecting response consistency issues in specific patient populations.