Originally developed in 1957 by Harrison Gough, the California Psychological Inventory (CPI) is a leading non-clinical personality inventory test that evaluates interpersonal behavior and social interaction of normal individuals. The standard 434 question test is administered in 45 to 60 minutes in true-false format, and is similar in design to the MMPI. Upon scoring, the test produces measurements along 20 “folk” scales of character, along the lines of Weberian prototypical exemplars.

After interpretation, these scores are used to classify subjects as either:

  1. Alpha: External, Norm Favoring
  2. Beta: Internal, Norm Favoring
  3. Gamma: External, Norm Doubting
  4. Delta: Internal, Norm Doubting

The scales were developed from an initial normative sample consisting of six thousand men and seven thousand women, which while not constructed through random selection, nonetheless captured a comprehensive cross-section of society. The reliability of the CPI has been assessed as to its internal consistency, as judged by alpha (.77 median) and test-retest (medians: 1 year=. 68, 5 year=.56, 25 year .58). The CPI has been shown to have predictive power in regard both to an individual’s behavior as well as subjective judgments of him made by others. Because of its relative thrift, brevity, and effectiveness, the CPI is widely used in business and governmental organizations.

The California Psychological Inventory, also referred to as the CPI-434, was originally published in 1957, and the version currently in use is the third edition. The latest revision of the California Psychological Inventory was in 1996 (Saladin, p.2). In 2002, a new version of the California Psychological Inventory was published, the CPI-260, which is a shorter version of the original California Psychological Inventory test.

The author of the California Psychological Inventory (CPI-434 and CPI-260) is Harrison G. Gough, PhD, and the publisher is Consulting Psychologists Press, in Palo Alto, California. The average cost of the basic administration materials, including a manual, item booklet, Interpretation guide and a packet of answer sheets is $462, and can be purchased through the publishing company (http://www.cpp.com).

The California Psychological Inventory was designed as a non-clinical Personality Inventory (Saladin, p.2). The test is a 434-item instrument in true-false format, and the design format is similar to the MMPI. It can be scored either by hand or computer (http://www.cpp.com).

The California Psychological Inventory was originally designed for group administration; however, it can also be administered individually (Megargee, p.5). The test is untimed, and the average length of time for administration is 45-60 minutes.

To administer the California Psychological Inventory, an examiner must have a Level C Qualification. To obtain this level of qualification, the examiner must have satisfactorily completed a course in the interpretation of Psychological tests at an accredited college or university, and possess an advanced degree in a profession that provides specialized training in the interpretation of psychological assessments (http://www.cpp.com).

The intended population of the California Psychological Inventory is normal individuals aged 12 and older, however the content is geared primarily toward students and young adults (Megargee, p.5). The test requires a fourth-grade reading level, unless the items are read aloud to the respondents (Megargee, p.5).

The purpose of the California Psychological Inventory is to measure and evaluate interpersonal behavior and social interaction within normal individuals. Harrison Gough defined the purpose of the test’s sales “to forecast what a person will say and do under defined conditions, and to identify individuals who will be described in characteristic ways by others who know them well or who observe their behavior in particular contexts.” (http://www.cpp.com)

The items on the California Psychological Inventory produce scores for the following 20 folk scales: Capacity for Status, Sociability, Social Presence, Self-Acceptance, Sense of Well Being, Responsibility, Socialization, Self-Control, Tolerance, Good Impression, Communality, Achievement via Conformance, Achievement via Independence, Intellectual Efficiency, Psychological Mindedness, Femininity/Masculinity Independence, Flexibility and Empathy (http://www.cpp.com).

The twenty scales are divided into four classes, including measures of poise, self-assurance and inter-personal proclivities; measures of normative orientation and values; measures of cognitive and intellectual functioning; and measures of Role and Personal Style (http://www.cpp.com).

For scoring the California Psychological Inventory, the raw scores for each scale are transferred to a profile sheet. By plotting the scores on a profile sheet, they are converted to T-scores: standard scores with a mean of 50 and a standard deviation of 10 (Megargee, p.5).

The scores are interpreted and documented into three different reports, the Profile, Narrative, and Configurable Analysis. The interpreted scores identify an individual as being one of four types: an Alpha-External, Norm Favoring; Beta-Internal, Norm Favoring; Gamma-External, Norm Doubting; or a Delta-Internal, Norm Doubting (Saladin, p.25-28).

The description of an Alpha-External, Norm Favoring includes personality characteristics including forceful, dominant, ambitious, assertive, extroverted and action oriented (Saladin, p.25). The personality characteristics of a Beta-Internal, Norm Favoring include low keyed, nurturant, responsible, stable, dependable and predictable (Saladin, p.26). For Gamma-External, Norm Doubting, characteristics include innovative, clever, adventurous, and questioning of the status quo (Saladin, p.27). The common personality characteristics of a Delta-Internal, Norm Doubting include reflective, detached, preoccupied and perceptive (Saladin, p.28).

In developing the California Psychological Inventory, Harrison Gough avoided using a theory based inventory, and instead, opted to use the approach of examining the setting in which the test is to be used and developing measurements based on the constructs already in operational usage there (Megargee, p.12). In this way, Gough proposed, the scales have general direct relevance because they are dealing with concepts which have already attained a degree of functional validity (Megargee, p.12). He referred to the 20 scales of the California Psychological Inventory as “folk scales”. For the actual method of test and item construction, Gough used the External Criterion method for deriving the majority of the scales, and the rational procedures of Internal Consistency Analysis for the remainder (Megargee, p.25).

In development of the California Psychological Inventory, a normative sample was used that consisted of six thousand men and seven thousand women (Megargee, p. 6). The sample cannot be considered a true random or stratified sample for various reasons; however, the sample did include subjects of widely varying age, socioeconomic status, and geographical areas (Megargee, p. 6).

The procedures used in assessing the reliability of the California Psychological Inventory were internal consistency with alpha and test-retest. The Alpha reliabilities for the 20 folk scales ranged from .62 to .84, with .77 being the median (Saladin, p.3).

The test-retest reliabilities of the 20 folk scales were assessed for 1 year, 5 years, and 25 years after the initial assessment. For the 1 year test-retest assessment, the reliability at the High School level ranged from .51 to .84, with .68 as the median. For the 5 year test-retest assessment, the reliability at the adult level ranged from .36 to .73, with .56 as the median. For the 25 year test-retest assessment, the reliability at the adult level ranged from .37 to .82, with .58 being the median (Saladin, p.3).

Reliability was also assessed for 3 Vector scales, using internal consistency with alpha and test-retest. The Alpha median was .82, and .59-.77 was the range for test-retest (Saladin, p.3).

In assessing the validity of the California Psychological Inventory scales, Gough used two basic criteria. The first was that the scales must identify people who will behave in a specified way. Secondly, people with high scores must impress others as having the quality in question (Megargee, p.27). Additionally, Gough subjected the scales to a conceptual analysis to clarify what it is that each scale was assessing as well as exploring them for unexpected relationships and uses (Megargee, p.27). These analyses included formal validation studies. An acceptable amount of research on the converegent validity of the California Psychological Inventory has also been done. Correlations between individual CPI scales and relevant external criteria fall in the .2 to .5 range, which are typical for personality research (http://www.cpp.com). Information on item correlations and factorial analyses is unavailable.

Marketing for the California Psychological Inventory has been primarily aimed at business leaders, for use in finding and developing successful employees, identifying and developing leaders and creating efficient organizations. However, the CPI is used for measurement in a variety of settings. It is often used in schools and colleges for academic counseling, identifying leaders and predicting success; in clinics and counseling agencies for evaluating substance abuse, susceptibility to physical illness, marital discord, juvenile delinquency and criminality, and social immaturity; and for cross cultural and other research (http://www.cpp.com).

A range of informative studies have been done utilizing the California Psychological Inventory. In 1998, a study was published titled “Prediction of Dysfunctional Job Behaviors Among Law Enforcement Officers” (Sarchione, Cuttler, Muchinsky and Nelson-Gray,1998), and used three of the CPI scales – Responsibility, Socialization, and Self-Control. The study concluded that while the CPI was accurate and useful in assessing the construct of conscientiousness, it was not as accurate in hypothesizing construct-oriented life history indices (drug use, criminal, and work) (Sarchione, et al.,1998).

In 1996, a study was published titled “Psychometric Properties of the California Psychological Inventory Socialization Scale in Treatment-Seeking Alcoholics” (Kadden, Donovan, Litt and Cooney,1996). The study examined the psychometric properties of the CPI’s Socialization scale (So, used to assess sociopathy) with regard to alcoholics. The participants were 1,627 alcoholics taking part in a national trial of patient-treatment matching, and found that the distribution of CPI-So scores was consistent with that of other studies of alcoholics, and the findings support the reliability and validity of the scale with that population (Kadden, et al.,1996).

There are a number of general strengths in the California Psychological Inventory. These include its proven ability in predictive studies, and generally, people usually find that their personal descriptions match those that the scales suggest. An additional strength and one that is reported more so in the CPI-260, is that it is difficult for an individual to fake bad or fake good. The California Psychological Inventory is also praised for its versatility (Laufer,Skoog and Day (1982).

The California Psychological Inventory also has weakness. As mentioned, the normative group used in the test design be considered a true random or stratified sample. One reason is that racially, Caucasians are highly overrepresented in the sample (Megargee, p.6). In “Personality and Criminality: A Review of the California Psychological Inventory” (Laufer,et al.,1982), the authors point out that while research has been performed using various minority ethnic groups, the results are disquieting as they show that lower class, minority group members tend to obtain lower scores on almost all 20 CPI scales (Laufer, et al., 1982).. In order for this to be corrected, researchers are encouraged to consider the effect that certain variables (race, SES, IQ, etc) have on CPI scores (Laufer, et al., 1982). This weakness with the California Psychological Inventory is especially important in regard to the validity of predictive studies in prison populations, with parolees, etc.

An additional weakness with the California Psychological Inventory is the information available on its validity. While an adequate amount of information is available in regards to its reliability, with so little information available, it is difficult for one to determine the adequacy of the test’s validity.

Despite the bias within its initial normative sample and inability to compensate for socioeconomic status, the CPI has proven itself as a valuable predictor of both an individual’s future behavior and the peer’s assessments of the given individual. With relative parsimony and thrift, the CPI further provides a valuable analysis of individual personality, and avails those results in terms comprehensible to laypeople. The enduring applicability of the CPI has evinced itself in numerous recent studies that have successfully used the CPI in such wide-ranging applications as: the behavior of alcoholics, prediction of leadership capacity, and potential for law-enforcement effectiveness. The comprehensiveness and generally sound theoretical underpinnings of the CPI suggest high chances of its continued applicability.

References

Consulting Psychologists Press, Inc. Retrieved April 20, 2005 from
http://www.cpp.com

Kadden, Donovan, Litt and Cooney (1996). Psychometric Properties of the California Psychological Inventory Socialization Scale in Treatment-Seeking Alcoholics. Psychology of Addictive Behavior, Vol.10, 3, 131-146

Laufer, Skoog, and Day (1982). Personality and Criminality: a Review of the California Psychological Inventory, Journal of Clinical Psychology, Vol. 38, 3, 562-72

Megargee, Edwin I. (1972). The California Psychological Inventory Handbook. San Francisco: Jossey-Bass, Inc. Publishers. PP 2,5-6,12,25-27

Saladin, Steve. California Psychological Inventory Revised http://www.webs.uidaho.edu/saladin/510/CPI.pdf

Sarchione, Cuttler, Muchinsky and Nelson-Gray(1998). Prediction of Dysfunctional Job Behaviors Among Law Enforcement Officers. Journal of Applied Psychology, Vol. 83, 6, 904-912