What is the California Psychological Inventory (CPI)?

Introduction

The California Psychological Inventory (CPI) is a paper-and-pencil test designed for a comprehensive analysis of traits that describe a normal adult personality. The test itself consists of 462 statements about feelings and opinions, ethical and social attitudes, personal relationships, and characteristic behavior. The testee responds to each item as “true” or “false.” Responses to these statements are analyzed, first of all, according to how well they fit twenty different patterns, each of which corresponds to a specified personality characteristic. The personality characteristics that are assessed include such everyday traits as sociability, dominance, independence, responsibility, self-control, tolerance, and achievement. The individual test-taker’s scores on each scale are evaluated by how these scores compare with the range of scores established by a nationwide comparison group or norm group. Such comparisons also permit evaluating the test-taker on three structural scales that summarize patterns underlying the twenty primary scales at a more abstract and basic level: externality-internality (self-confident assertive extraversion versus introversion), norm-favoring versus norm-questioning (allegiance to the conventional social rules versus its lack), and the degree of one’s “realization” of these tendencies, an index of self-fulfillment or satisfaction.

Development

Harrison Gough, the author of the CPI, began assembling items relevant to the measurement of everyday personality characteristics in the late 1940s. It was 1957, however, before the completed eighteen scales of the CPI were published by Consulting Psychologist Press. In 1987, modest revisions in the scale were initiated. At this time, a few items were modified to reflect cultural changes, and two new primary scales, independence and empathy, were added to the original eighteen. The most important change, however, was the addition of the three summary, structural scales.

Two important principles governed the CPI’s development. The first of these was Gough’s interest in measuring “folk concepts,” characteristics which in many cultures and over centuries made sense to ordinary people. This principle was in contrast to many existing tests that assessed concepts based on psychiatric diagnosis or academic personality theories or were abstracted from a mathematical procedure called factor analysis.

A second guiding principle was that of empirical criterion keying, which means that the validity of items on scales, as well as the scales themselves, should be established by actual research. In such research, items and scales are tested to assure that people who show evident differences in real-life functioning answer the item or the scale in the different ways one would expect. For example, the socialization scale was conceived to measure moral uprightness in the sense of observing society’s rules and customs. One would expect that convicted felons would answer questions on this scale in ways different from Eagle Scouts, and felons would be expected to score much lower on this scale. Research verifying this difference supported the validity of the item and the scale. Hundreds of such predictions derived from the meaning of various CPI scales were tested. Only thereafter was the test considered valid.

Evaluation

A major criticism of the CPI is that there is much overlap between highly similar scales. Dominance and capacity for status, for example, seem to involve only slightly nuanced measurements of almost the same thing. It has been argued, therefore, that the essential information could be gleaned from fewer, simpler scales. Gough answered this criticism by pointing out that everyday descriptions of others by ordinary folk also show this sort of overlap. He also pointed out that the structural scales, added in 1987, permit such simple, efficient description of a personality without depriving the test-taker of the refined and detailed analysis offered by assessing twenty primary traits.

It has also been charged that the CPI is often employed beyond the uses for which its validity has been established. Clinicians are prone to apply the test to abnormal populations for which validity data is incomplete. The test has also been frequently used for people from cultures outside the United States and for minorities within the United States. Although Gough selected his “folk concepts” for their apparent cross-cultural relevance, validity studies in minority and Third World subcultures have been neglected. Interpreting the test results of those from different cultural backgrounds must, therefore, be done with caution.

These admitted limitations could be addressed by adding more studies of minority or clinical populations to the already impressive research with this instrument. For more than half a century, the CPI has served such purposes as predicting vocational choice, academic success, and antisocial behavior. Few other personality tests have been as thoroughly validated. Its many scales permit a detailed description of a person in language that makes sense. Useful and much used, the CPI remains one of the best personality tests for normal populations.

Bibliography

Anastasi, Anne, and Susan Urbina. Psychological Testing. 7th ed. Upper Saddle River: Prentice, 1997. Print.

Bolton, B. “Review of the California Psychological Inventory, Revised Edition.” Eleventh Mental Measurements Yearbook. Ed. J. J. Framer and J. C. Conly. Lincoln: Buros Institute of Mental Measurements, 1992. Print.

Gough, H. G. “The California Psychological Inventory.” Testing in Counseling Practice. Ed. C. E. Walker and V. L. Campbell. Hillsdale.: Erlbaum, 1992. Print.

Gough, H. G., and P. Bradley. “Delinquent and Criminal Behavior as Assessed by the Revised California Psychological Inventory.” Journal of Clinical Psychology 48 (1992): 298–308. Print.

Groth-Marnat, Gary. Handbook of Psychological Assessment. Rev. ed. New York: Wiley, 2009. Print.

Kulas, John T., Richard C. Thompson, and Michael G. Anderson. "California Psychological Inventory Dominance Scale Measurement Equivalence: General Population Normative and Indian, UK, and US Managerial Samples." Educational & Psychological Measurement 71.1 (2011): 245–57. Print.

Megargee, E. I. The California Psychological Inventory Handbook. San Francisco: Jossey, 1977. Print.

Melton, Gary B., et al. Psychological Evaluations for the Courts: A Handbook for Mental Health Professionals and Lawyers. 3d ed. New York: Guilford, 2007. Print.

Nestor, Paul, and Russell K. Schutt. Research Methods in Psychology: Investigating Human Behavior. Los Angeles: SAGE, 2012. Print.

Reynolds, Cecil R., and Ronald B. Livingston. Mastering Modern Psychological Testing: Theory & Methods. Boston: Pearson Education, 2012. Print.