Description

The K Scale of the Minnesota Multiphasic Personality Inventory (MMPI) is one of the validity scales used to assess the tendency of respondents to present themselves in a more positive or normal manner than they actually are. The K scale was designed to detect defensiveness and reservation, as well as the tendency toward social desirability in responses.

Purpose

The main purpose of the K Scale is to identify and correct response bias due to defensiveness, efforts to present a positive self-image, and reservation. It is used to improve the accuracy of MMPI results by considering the possibility that the respondent may not be answering honestly.

Analysis

The K Scale consists of 30 statements designed to detect defensiveness and the tendency toward social desirability. Respondents are asked to answer these statements as “true” or “false.” These statements involve issues related to self-esteem, acceptance of weaknesses, and coping with problems.
High scores on the K Scale may indicate that the respondent is attempting to present themselves in a more positive manner, whereas low scores may indicate greater honesty or even excessive self-criticism.

Scoring

Scoring of the K Scale is done by summing the “true” or “false” responses across the 30 statements. Responses are coded as “1” for the socially desirable answer and “0” for the socially undesirable answer. The total score ranges from 0 to 30, with higher scores indicating greater defensiveness and a tendency toward social desirability.
K Scale scores are also used to adjust the results of other MMPI scales, in order to correct for possible bias due to defensiveness or social desirability.

References

Greene, R. L. (2011). The MMPI-2: An Interpretive Manual (3rd ed.). Allyn & Bacon.
Butcher, J. N., Dahlstrom, W. G., Graham, J. R., Tellegen, A., & Kaemmer, B. (1989). Minnesota Multiphasic Personality Inventory-2 (MMPI-2): Manual for administration and scoring. University of Minnesota Press.
Hathaway, S. R., & McKinley, J. C. (1943). The Minnesota Multiphasic Personality Inventory Manual. Psychological Corporation.
Graham, J. R. (2006). MMPI-2: Assessing Personality and Psychopathology (4th ed.). Oxford University Press.