16PF Questionnaire

A characteristic of the 16PF items is that, rather than asking respondents to self-assess their personality as some instruments do (e.g., "I am a warm and friendly person; I am not a worrier; I am an even tempered person."), they tend instead to ask about daily, concrete situations, e.g.:

• When I find myself in a boring situation, I usually "tune out" and daydream about other things. True/False.
• When a bit of tact and convincing is needed to get people moving, I'm usually the one who does it. True/False.

Cattell argued that self-ratings relate to self-image, and are affected by self-awareness, and defensiveness about one's actual traits. The 16PF provides scores on 16 primary personality scales and five global personality scales, all of which are bi-polar (both ends of each scale have a distinct, meaningful definition). The instrument also includes three validity scales:

• a bi-polar Impression Management (IM) scale,
• an Acquiescence (ACQ) scale, and
• an Infrequency (INF) scale.

The Impression Management (IM) scale is a bipolar scale with high scores reflecting a preponderance of socially desirable responses and low scores reflecting a preponderance of socially undesirable responses. Possible reasons for an extremely high Impression Management score include: the examinee may actually behave in highly socially desirable ways, and responses are accurate self-descriptions; responses reflect an unconscious distortion consistent with the examinee's self-image but not with their behavior; or deliberate self-presentation as behaving in a highly socially desirable manner. A low impression management score suggests an unusual willingness to admit undesirable attributes or behaviors and can occur when an examinee is unusually self-critical, discouraged, or under stress.

The Acquiescence (ACQ) scale's purpose is to index the degree to which the examinee agreed with items regardless of what was being asked. A high score might indicate that the examinee misunderstood the item content, responded randomly, has an unclear self-image, or had a "yea-saying" response style.

The Infrequency (INF) scale comprises the most statistically infrequent responses on the test, which are all middle (b) responses and appear in the test booklet with a question mark. A score above the 95th percentile may indicate that the examinee had trouble reading or comprehending the questions, responded randomly, experienced consistent indecisiveness about the a or c response choice, or tried to avoid making the wrong impression by choosing the middle answer rather than one of the more definitive answers.

Administration of the test takes about 35–50 minutes for the paper-and-pencil version and about 30 minutes by computer. The test instructions are simple and straightforward and the test is un-timed; thus, the test is generally self-administrable and can be used in either an individual or a group setting. The 16PF test was designed for adults at least age 16 and older, but there are also parallel tests for various younger age ranges (e.g., the 16PF Adolescent Personality Questionnaire[14]).

The 16PF Questionnaire has been translated into more than 30 languages and dialects.[13] Thus the test can be administered in different languages, scored based on either local, national, or international normative samples, and computerized interpretive reports provided in about 23 different languages. The test has generally been culturally adapted (rather than just translated) in these countries, with local standardization samples plus reliability and validity information collected locally and presented in individual manuals.

The test can be hand-scored using a set of scoring keys, or computer-scored by mailing-in or faxing-in the answer sheet to the publisher IPAT. There is also a software system that can be used to administer, score, and provide reports on the test results directly in the professional's office; and an Internet-based system that can also provide administration, scoring, and reports in a range of different languages.

After the test has been administered there is a total score computed from each of the 16 personality factors. These totals have been created in a way to correlate to the sten scale.[28] Scores on the 16PF are presented on a 10-point scale, or standard-ten scale. The sten scale has a mean of 5.5 and a standard deviation of 2, with scores below 4 considered low and scores above 7 considered high.[29] The sten scales are bipolar, meaning that each end of the scale has a distinct definition and meaning. Because bipolar scales are designated with "high" or "low" for each factor, a high score should not be considered to reflect a positive personality characteristic and a low score should not be considered to reflect a negative personality characteristic.

Cattell and Schuerger provided six steps that outline how they recommend interpreting the results of the 16PF:[30]

1. Consider the context of the assessment.
2. Evaluate the Response Style Indexes by first checking responses on Factor B, and then looking at scores on the Infrequency, Impression Management, and Acquiescence scales.
3. Evaluate the Global Scale scores.
4. Evaluate the Primary Scales in the context of the Global Scales
5. Consider scale interactions
6. Integrate 16PF results in relation to the assessment question

There are about a dozen computer-generated interpretive reports that can be used to help interpret the test for different purposes, for example:

• Career Development Report
• Karson Clinical Report
• Cattell Comprehensive Personality Interpretation
• Teamwork Development Report,
• Management Potential Report,
• Security Selection Report
• Leadership Coaching Report

There are also many books that help with test interpretation, for example,

• 16PF Interpretation in Clinical Practice (Karson, Karson, & O'Dell, 1997),[31]
• The 16PF: Personality in Depth (Cattell, H.B., 1989),[32] and
• Essentials of the 16PF (Cattell, H.E. & Schuerger, J.M, 2003)[33]

The 16PF traits are also included in the Psychological Evaluation Questionnaire (PEQ), which combines measures of both normal and abnormal personality traits into one test (Cattell, Cattell, Cattell, Russell, & Bedwell, 2003)[30]

The 16PF Questionnaire was created from a fairly unusual perspective among personality tests. Most personality tests are developed to measure just the pre-conceived traits that are of interest to a particular theorist or researcher. The main author of the 16PF, Raymond B. Cattell, had a strong background in the physical sciences, especially chemistry and physics, at a time when the basic elements of the physical world were being discovered, placed in the periodic table, and used as the basis for understanding the fundamental nature of the physical world and for further inquiry. From this background in the physical sciences, Cattell developed the belief that all fields are best understood by first seeking to find the fundamental underlying elements in that domain, and then developing a valid way to measure and research these elements (Cattell, 1965).[40]

Personality research author Schuerger stated that:

Cattell's goal in creating the 16PF Questionnaire was to provide a thorough, research-based map of normal personality.[41]

When Cattell moved from the physical sciences into the field of psychology in the 1920s, he described his disappointment about finding that it consisted largely of a wide array of abstract, unrelated theories and concepts that had little or no scientific bases. He found that most personality theories were based on philosophy and on personal conjecture, or were developed by medical professionals, such as Jean Charcot and Sigmund Freud, who relied on their personal intuition to reconstruct what they felt was going on inside people, based on observing individuals with serious psycho-pathological problems. Cattell (1957)[4] described the concerns he felt as a scientist:

"In psychology there is an ocean of spawning intuitions and comfortable assumptions which we share with the layman, and out of which we climb with difficulty to the plateaus of scientific objectivity....Scientific advance hinges on the introduction of measurement to the field under investigation….Psychology has bypassed the necessary descriptive, taxonomic, and metric stages through which all healthy sciences first must pass….If Aristotle and other philosophers could get no further by sheer power of reasoning in two thousand years of observation, it is unlikely that we shall do so now.... For psychology to take its place as an effective science, we must become less concerned with grandiose theory than with establishing, through research, certain basic laws of relationship." (p.3-5)

Thus, Cattell's goal in creating the 16PF Questionnaire was to discover the number and nature of the fundamental traits of human personality and to develop a way to measure these dimensions. At the University of London, Cattell worked with Charles Spearman who was developing factor analysis to aid in his quest to discover the basic factors of human ability. Cattell thought that could also be applied to the area of personality. He reasoned that human personality must have basic, underlying, universal dimensions just as the physical world had basic building blocks (like oxygen and hydrogen). He felt that if the basic building blocks of personality were discovered and measured, then human behavior (e.g., creativity, leadership, altruism, or aggression) could become increasingly understandable and predictable.

In 1936 Gordon Allport and H.S. Odbert hypothesized that:

Those individual differences that are most salient and socially relevant in people's lives will eventually become encoded into their language; the more important such a difference, the more likely is it to become expressed as a single word.

This statement has become known as the Lexical Hypothesis, which posits that if there is a word for a trait, it must be a real trait. Allport and Odbert used this hypothesis to identify personality traits by working through two of the most comprehensive dictionaries of the English language available at the time, and extracting 18,000 personality-describing words. From this gigantic list they extracted 4500 personality-describing adjectives which they considered to describe observable and relatively permanent traits.

Cattell and his colleagues began a comprehensive program of international research aimed at identifying and mapping out the basic underlying dimensions of personality. Their goal was to systematically measure the widest possible range of personality concepts, in a belief that "all aspects of human personality which are or have been of importance, interest, or utility have already become recorded in the substance of language" (Cattell, R. B., 1943, p. 483).[42] They wanted to include every known personality dimension in their investigation, and thus began with the largest existing compilation of personality traits (Allport and Odbert, 1936).[43] Over time, they used factor analysis to reduce the massive list of traits by analyzing the underlying patterns among them. They studied personality data from different sources (e.g. objective measures of daily behavior, interpersonal ratings, and questionnaire results), and measured these traits in diverse populations, including working adults, university students, and military personnel. (Cattell, 1957, 1973).[4][44]

The 16 Personality Factors were identified in 1949 by Raymond Cattell.[45] He believed that in order to adequately map out personality, one had to utilize L-Data (life records or observation), Q data (information from questionnaires), and T-data (information from objective tests).[46] The development of the 16PF Questionnaire, although confusingly named, was an attempt to develop an adequate measure of T-data.

Cattell analyzed the list of 4500 adjectives and organized the list of adjectives into fewer than 171 items and asked subjects to rate people whom they knew on each of the adjectives on the list (an example of L-data because the information was gathered from observers). This allowed Cattell to narrow down to 35 terms and factor analysis in 1945, 1947 and 1948 revealed a 11 or 12 factor solution.[47][48][49]

In 1949 Cattell found that there were 4 additional factors, which he believed consisted of information that could only be provided through self-rating. This process allowed the use of ratings by observers, questionnaires, and objective measurements of actual behavior.[44][50][51] In 1952 the ILLIAC I became available at the University of Illinois at Urbana-Champaign to be used for factor analysis.[52]

Together the original 12 factors and the 4 covert factors made up the original 16 primary personality factors.[53] As the five factor theory gained traction and research on the 16 factors continued, subsequent analysis identified five factors underlying the 16 factors. Cattell called these global factors.

The 16PF factorial structure resembles that of Szondi test and the Berufsbilder test (BTT), despite being based on different theories.[54]

Because the 16PF dimensions were developed through factor analysis, construct validity is provided by studies that confirm its factor structure. Over several decades of factor-analytic study, Cattell and his colleagues gradually refined and validated their list of underlying source traits. The search resulted in the sixteen unitary traits of the 16PF Questionnaire. These traits have remained the same over the last 50 years of research. In addition, the 16PF Questionnaire traits are part of a multi-variate personality model that provides a broader framework including developmental, environmental, and hereditary patterns of the traits and how they change across the life span (Cattell, 1973, 1979, 1980).[55][56]

The validity of the factor structure of the 16PF Questionnaire (the 16 primary factors and 5 global factors) has been supported by more than 60 published studies (Cattell & Krug, 1986; Conn & Rieke, 1994; Hofer and Eber, 2002).[57][58][59] Research has also supported the comprehensiveness of the 16PF traits: all dimensions on other major personality tests (e.g., the NEO Personality Inventory, the California Psychological Inventory, the Personality Research Form, and the Myers-Briggs Type Indicator) have been found to be contained within the 16PF scales in regression and factor-analytic studies (Conn & Rieke, 1994; Cattell, 1996).[34]

Since its release in 1949, the 16PF Questionnaire has been revised four times: once in 1956, once in 1962, once in 1968, and the current version was developed in 1993. The US version of the test was also re-standardized in 2002, along with the development of forms for children and teenagers; versions for the UK, Ireland, France and the Netherlands were re-standardised in 2011. Additionally, there is a shortened form available primarily for employee selection and the questionnaire has been adapted into more than 35 languages. The questionnaire has also been validated in a range of international cultures over time.[60][61][62]

The 16PF was distributed through the Institute for Personality and Ability Testing (IPAT), founded by Cattell and based in Savoy, Illinois.[63] In January 2003, the Institute was purchased by UK private company, OPP Limited, who administered the 16PF worldwide.[63] It later became a subsidiary of Performance Assessment Network (PAN)[64] which in 2017 was acquired by PSI.[65]