'False Feigners': Examining the Impact of Non-Content-Based Invalid Responding on the Minnesota Multiphasic Personality Inventory-2 Restructured Form Content-Based Invalid Responding Indicators

Misinterpretation of non-content-based invalid (e.g., random, fixed) responding as overreporting or underreporting

is likely to adversely impact test interpretation and could bias inferences about examinee intentions.

We examined the impact of non-content-based invalid responding on the following Minnesota Multiphasic

Personality Inventory-2 Restructured Form (MMPI-2-RF) content-based invalid responding indicators: Infrequent

Responses (F-r), Infrequent Psychopathology Responses (FP-r), Infrequent Somatic Responses (FS),

Symptom Validity (FBS-r), Response Bias Scale (RBS), Uncommon Virtues (L-r), and Adjustment Validity

(K-r). In 4 samples from which invalid responders were excluded, we systematically inserted increasing

percentages of random, acquiescent, or counter-acquiescent item responses ranging from 0% to 100% and

examined the impact that non-content-based invalid response styles had on the content-based invalid responding

indicators. F-r, FP-r, FS, RBS, and L-r were susceptible to non-content-based invalid responding, whereas

FBS-r and K-r were unaffected. Individuals with Variable Response Inconsistency (VRIN-r) and True

Response Inconsistency (TRIN-r) elevations were removed, and the frequencies of content-based invalid

responding elevations were then reexamined for false indications of feigning. Findings were consistent across

samples and emphasize the need to screen for non-content-based invalid responding before screening for

content-based invalid responding in the assessment of personality and psychopathology. VRIN-r and TRIN-r

were useful in detecting most— but not all—cases of non-content-based invalid responding. A small but

meaningful percentage of the remaining individuals were misclassified as overreporters (i.e., false feigners) by

FP-r and FS. Clinicians should interpret FP-r and FS with some caution in the presence of moderate levels of

non-content-based invalid responding. Post hoc examinations of scale characteristics indicated that the most

susceptible scales were brief, consisted of rarely endorsed items, included a relatively high percentage of

true-keyed items, and required a low percentage of endorsed items to reach clinical significance.