Inconsistent responding to repeated MMPI items: is its major cause really carelessness?

Area of Science:

• Psychological assessment
• Personality testing
• Psychometrics

Background:

• The Minnesota Multiphasic Personality Inventory (MMPI) is a widely used personality assessment tool.
• Inconsistent responses to repeated items have been proposed as an indicator of carelessness in test-taking.
• This interpretation assumes a single cause for response inconsistency.

Purpose of the Study:

• To investigate the underlying causes of response inconsistency on repeated MMPI items.
• To differentiate between maladjustment, carelessness, and indecision as sources of inconsistency.
• To evaluate the validity of using response inconsistency as a measure of carelessness.

Main Methods:

• Administered the full MMPI twice to 202 normal undergraduate participants.
• Analyzed response patterns to identify inconsistencies between the two administrations.
• Investigated the relationship between inconsistency and potential causal factors (maladjustment, carelessness, indecision).

Main Results:

• Response inconsistency was not solely attributable to carelessness.
• Indecision emerged as a significant, potentially more dominant, factor contributing to inconsistency.
• Maladjustment and carelessness also played roles, but indecision's impact was notable.

Conclusions:

• The assumption that MMPI item inconsistency reflects only carelessness is questionable.
• Indecision is a critical factor influencing response consistency on personality inventories.
• Rethinking the interpretation of repeated item inconsistencies in personality assessments is warranted.