Steve Strack's
Personality Adjective Check List (PACL)

Development of the PACL
Test Availability
Comparison With the MCMI™
Millon's Personalities as Measured by the PACL
Clinical and Research Uses
For More Information or to Order the PACL
References
Stephen Strack, Ph.D.

DEVELOPMENT OF THE PACL

In deciding on a format for creating the measure, two factors were primary. First, Millon's empirical work had taught him that fast and simple tests were the ones most often selected for use by investigators and completed successfully by clients. Second, I wanted the measure to build on the interpersonal roots of Millon's theory, a strong attraction for me given my previous training and work at Berkeley. Therefore, in the tradition of LaForge and Suzcek's (1955) Interpersonal Check List, and Gough's (Gough & Heilbrun, 1983) Adjective Check List, we decided to develop a quick and easy-to-complete adjective measure that would allow for both self-reports and observer ratings.

Unfortunately, measures could not be developed for the three severe schizoid, cycloid, and paranoid personalities because of extremely low endorsement rates (< 5%) for most keyed items. Rather than throw away the handful of good items that remained for these measures, they were combined into an experimental problem indicator scale, PI, which we thought might be useful in identifying persons with personality disorders.

In addition to the personality and experimental scales, I developed three response bias indices to aid in the detection of faked protocols (Strack, 1991c), namely, Random (R), Favorable (F), and Unfavorable (UF). Separate groups of college students were asked to complete the PACL randomly, or with intent to give an overly favorable or overly unfavorable self-report. Discriminant function analyses were used to distinguish the faked tests from PACLs completed under the normal instructional set. Equations were derived from these analyses (separately for men and women) and were cross-validated with independent samples. The equations were able to correctly identify a large majority of faked (75%-91%) and normal tests (60%-94%).

Wiggins and Pincus (1989; Pincus & Wiggins, 1990) examined the PACL in the context of MMPI™ personality disorder scales, Big Five Interpersonal Adjective Scales (IAS-B5), the NEO-PI, and a circumplex version of Horowitz's Inventory of Interpersonal Problems. PACL scales exhibited anticipated relationships with each of the tests in correlational, canonical, and factor analyses. For example, PACL Introversive and Sociable were loaded (in opposite directions) on a factor that included the MMPI™ Schizoid and Histrionic scales, NEO-PI Extraversion, and IAS-B5 Dominance. PACL Forceful was correlated .59 with interpersonal problems associated with dominance behavior, while PACL Cooperative was correlated .48 with problems involving exploitation by others.

In keeping with the emphasis on normality, PACL scales were normed as T scores rather than BR scores. Normative data (Strack, 1991c) were obtained from 2507 normal adults between the ages of 16 and 72. Subjects were sampled between 1980-1986 with 90% coming from colleges and 10% from businesses. Men comprised 47.4% of sample and women 52.6%. Ethnic make-up was 65.2% non-Hispanic White, 17.3% Hispanic, 9.1% Black, 7.6% Asian, and 0.8% Native American Indian or Eskimo.

21st Century Assessment, located in South Pasadena, CA (USA), publishes the PACL as a paper-and-pencil measure that can be hand scored or entered into a computer file via optical scanner. Full-color, computerized versions of the check list for DOS (AUTOPACL; Robbins, 1998) and Windows (WinPACL; Robbins, 1999) are also available that permit computer administration of the test, scoring, and printing of profile plots of scores as well as narrative interpretations. WinPACL and AutoPACL are available now for immediate download from this site! Go to the PACLStore to obtain your free copy of WinPACL or AutoPACL for evaluation. The WinPACL and AutoPACL programs allow for unlimited uses on a single computer and, as an aid to researchers, can produce exportable files containing test data for multiple subjects. The narrative interpretations were written by me for use in counseling and personnel settings, and were based on Millon's writings, empirical information obtained during test construction and validation, and clinical experience with the test. Additional information on how to contact the publisher may be found by clicking here.

Strack, Lorr, and Campbell (1990) examined the circular ordering of MCMI-II™ personality disorder scales in a mixed group of psychiatric patients and compared results with those from the PACL among normal adults. Plotted against the orthogonally-rotated first two principal components, they found a reasonably good circle for MCMI-II™ scales (using residual scores) that, for the most part, followed Millon's (1987, p. 20) predictions. Ordering for the PACL scales was similar, although a less complete circle was noted: Sociable, Confident, and Forceful were loaded opposite Introversive, Inhibited, and Sensitive on one dimension, while Cooperative and Respectful defined one end of a second dimension but had no opposing scales.

With regard to the appearance of Millon's personalities in normal form, what can be offered at this point is a portrait of each style based on Millon's theory, empirical findings from studies associating PACL scales with other measures, and clinical experience with the test. Summaries of empirical findings can be found in Strack (1991c, 1993). The following descriptions represent normal prototypes of persons who obtain high scores on the individual scales. In practice, of course, people are seldom prototypical, instead exhibiting a mixture of traits from multiple styles. Nevertheless, these descriptions flesh-out various aspects of normal personality not readily grasped by extrapolations from Millon's writings on pathological character. Especially noteworthy among the normal styles are their positive dispositional features and interpersonal attitudes. Even less desirable traits are placed within a normal frame of reference.

Aloof, introverted, and solitary, these persons usually prefer distant or limited involvement with others and have little interest in social activities, which they find unrewarding. Appearing to others as nonchalant and untroubled, they are often judged to be easy-going, mild-mannered, quiet, and retiring. They frequently remain in the background of social life and work quietly and unobtrusively at a job. At school or in the workplace these people do well on their own, are typically dependable and reliable, are nondemanding, and are seldom bothered by noise or commotion around them. They are often viewed as level-headed and calm. However, these individuals may appear unaware of, or insensitive to, the feelings and thoughts of others. These characteristics are sometimes interpreted by others as signs of indifference or rejection, but reveal a sincere difficulty in being able to sense others' moods and needs. Introversive persons can be slow and methodical in demeanor, lack spontaneity and resonance, and be awkward or timid in social or group situations. They frequently view themselves as being simple and unsophisticated, and are usually modest in appraising their own skills and abilities. At the same time, their placid demeanor and ability to weather ups and downs without being ruffled are traits frequently prized by friends, family members, and co-workers.

As with the introversive style, the inhibited personality is marked by a tendency toward social withdrawal. However, for inhibited individuals this pattern is motivated not by disinterest, but by a fear of negative consequences. Inhibited persons tend to be sensitive to their own feelings and to those of others. They often anticipate that others will be critical or rejecting of them, and because of this they frequently seem shy or skittish in unfamiliar surroundings. In this regard, family members and acquaintances may see them as being unnecessarily nervous, wary, and fearful. Although inhibited persons tend to get along reasonably well with others, they are often difficult to get to know on a personal level. These individuals usually wish that they could be at ease with others and tend to desire closeness, but they often are just too uncertain of the consequences of closeness and intimacy to let their guard down. As a result, they may experience feelings of loneliness, but be unable or unwilling to do anything about them. Because of their sensitivity to others, inhibited persons are often described as kind, considerate, and empathic by close acquaintances. Inhibited persons often prefer to work alone or in a small group with people they can come to know well. They do best in a stable work environment where stimulation and commotion are kept at low to moderate levels. Persons working with inhibited types need to appreciate their sensitivity to both positive and negative feedback, as well as their need to build trust over a long period of time.

Cooperative persons can be identified by a need for approval and affection, and by a willingness to live in accord with the desires of others. They usually adapt their behavior to the standards of others but in the process may deny their own needs. Interpersonally, these individuals are often cooperative, reliable, considerate of others, and deferential. They may appear even-tempered, docile, obliging, self-effacing, ingratiating, or naive. Cooperative individuals often see themselves as being modestly endowed in terms of skills and abilities. They are often pleased when they can rely on others and may feel insecure when left on their own. Especially when faced with difficult or stressful situations, cooperative persons seek others to provide authority, leadership, and direction. They often prefer group work environments and will typically excel in them if given support and guidance. They are usually willing to follow directions and cooperate with co-workers in team efforts.

Like cooperative personalities, sociable individuals have a need for attention and approval. However, unlike cooperative persons sociable types take the initiative in assuring their reinforcements by being center-stage. They are characterized by an outgoing, talkative, and extroverted style of behavior and tend to be lively, dramatic, and colorful. These people are typically viewed by others as spontaneous, clever, enthusiastic, and vigorous. They can be quite sensitive to the needs and wants of others, at least to those aspects which will help them get the attention they seek. Sociable individuals may also be seen as fickle in their attachments. They may have quickly shifting moods and emotions, and may come across as shallow and ungenuine. These persons tend to prefer novelty and excitement, and are bored by ordinary or mundane activities. Like cooperative personalities, sociable individuals seem uncomfortable or deflated when left on their own. Not surprisingly, sociable types often excel in group work environments where they can excerise their showy style. They often do well interacting with the public, may be skilled and adept at rallying or motivating others, and will usually put their best side forward even in difficult circumstances.

Aloof, calm, and confident, these personalities tend to be egocentric and self-reliant. They may have a keen sense of their own importance, uniqueness, or entitlement. Confident individuals enjoy others' attention and may be quite bold socially, although they are seldom garish. They can be self-centered to a fault and may become so preoccupied with themselves that they lack concern and empathy for others. These persons have a tendency to believe that others share, or should share, their sense of worth. As a result, they may expect others to submit to their wishes and desires, and to cater to them. Ironically, the confident individual's secure appearance may cover feelings of personal inadequacy and a sensitivity to criticism and rejection. Unfortunately, they usually do not permit others to see their vulnerable side. When feeling exposed or undermined these individuals are frequently disdainful, obstructive, or vindictive. In the workplace, confident persons like to take charge in an emphatic manner, often doing so in a way that instills confidence in others. Their self-assurance, wit, and charm often win them supervisory and leadership positions.

Like confident persons, forceful individuals can be identified by an inclination to turn toward the self as the primary source of gratification. However, instead of the confident personality's internalized sense of self-importance, forceful people seem driven to prove their worthiness. They are characterized by an assertive, dominant, and tough-minded personal style. They tend to be strong-willed, ambitious, competitive, and self-determined. Feeling that the world is a harsh place where exploitiveness is needed to assure success, forceful individuals are frequently gruff and insensitive in dealing with others. In contrast to their preferred, outwardly powerful appearance, these individuals may feel inwardly insecure and be afraid of letting down their guard. In work settings, these personalities are often driven to excel. They work hard to achieve their goals, are competitive, and do well where they can take control or work independently. In supervisory or leadership positions these persons usually take charge and see to it that a job gets done. However, they often need to temper an inclination to demand as much of others as they do of themselves.

Responsible, industrious, and respectful of authority, these individuals tend to be conforming and work hard to uphold rules and regulations. They have a need for order and are typically conventional in their interests. These individuals can be rule-abiding to a fault, however, and may be perfectionistic, inflexible, and judgmental. A formal interpersonal style and notable constriction of affect can make some respectful persons seem cold, aloof, and withholding. Underneath their social propriety there is often a fear of disapproval and rejection, or a sense of guilt over perceived shortcomings. Indecisiveness and an inability to take charge may be evident in some of these persons due to a fear of being wrong. However, among co-workers and friends, respectful personalities are best known for being well-organized, reliable, and diligent. They have a strong sense of duty and loyalty, are cooperative in group efforts, show persistence even in difficult circumstances, and work well under supervision.

Sensitive personalities tend to be unconventional and individualistic in their response to the world. They march to the beat of a different drummer and are frequently unhappy with the status quo. They may be quick to challenge rules or authority deemed arbitrary and unjust. They may also harbor resentment without expressing it directly and may revert to passive-aggressive behavior to make their feelings known. Many sensitive people feel as if they don't fit in, and view themselves as lacking in interpersonal skills. In fact, to others they often appear awkward, nervous, or distracted, and seem angry or dissatisfied with themselves and others. They can be indecisive and have fluctuating moods and interests. An air of uncertainty and general dissatisfaction may reflect an underlying dependency and sense of personal inadequacy. With their best side forward, sensitive persons can be spontaneous, creative, and willing to speak out for what they believe in. These qualities make them especially suited to jobs that are not rule-bound, that give them a certain independence from supervision, and that require unusual duties or creative expression.

Items for this scale were compiled from adjectives measuring the schizoid, cycloid, and paranoid personalities, for example, "chaotic," "fragmented," "depressed," and "suspicious." While the scale does not define a personality style, high scores are indicative of personality problems and the potential for disorder. High scorers possess personality disorder traits and symptoms such as low ego-strength and affective instability. They are likely to appear anxious, dysphoric, and fearful, exhibit strong self-doubt, and express dissatisfaction with themselves and others. They may have long-standing adjustment problems in major areas of life such as work, school, and relationships. Those who score high on this scale are not likely to fit the same picture of normality as are low scorers (e.g., by exhibiting interpersonal rigidity and maladaptiveness), but further assessment is advised before drawing conclusions regarding the presence of a disorder.

An important factor to keep in mind when using the PACL in clinical settings is that the test measures normal trait characteristics, not personality disorder features. High scores on the PACL indicate that an individual possesses more of the traits of a particular normal personality style than other adults in the general population. For example, the higher an individual's score is above T = 50 on any particular scale, the more likely it is that he or she will fit the prototype descriptions given earlier. The test won't assess disordered personality features beyond those measured by the PI scale.

Cross-cultural research is needed to assess the similarities and differences in trait structure of Millon's personalities based on cultural influences. As an interpersonal model, one would expect cultural differences to be evident among Millon's personalities at the nomothetic (normative) level of measurement. From an idiographic perspective, one would also expect test interpretation to differ somewhat by culture. For example, in mainstream America independence is valued more than dependence. This may be reflected in our assessment of an individual's strengths and weaknesses when, for example, we suggest that a confident and forceful style will help a person get ahead in business while a cooperative style may be a liability in the same environment. In other cultures dependence and cooperativeness are more highly valued than traits of independence, and changes in test interpretation would follow. The PACL is now available for research use in Chinese, Dutch, Italian, Portuguese, and Spanish languages, and I strongly support cross-cultural investigations of any kind.

Inquiries about the PACL are welcome, and may be directed to the publisher or the author. For current pricing of PACL test products and to place an order, please go to the PACLStore where you can order products and download a free evaluation copy of WinPACL or AutoPACL. VISA, MASTERCARD, checks, and purchase orders are accepted online at the PACLStore or by postal mail, telephone or FAX. Shipping is available to all domestic and international locations.

Dr. Stephen Strack was introduced to personality theory and assessment as an undergraduate at U.C. Berkeley by such people as Jack and Jeanne Block, Harrison Gough, Kenneth Craik, and James Coyne. As a graduate student at the University of Miami he worked with Theodore Millon, the late Robert B. Meagher, Jr., and Catherine Green. Since receiving his PhD in clinical psychology (1983), Dr. Strack has continued to work in the area of personality, most notably with Maurice Lorr, with whom he co-edited the book Differentiating Normal and Abnormal Personality (Springer, 1994). He is a nationally recognized expert on Millon's personality theory and measures. He is a Fellow of the American Psychological Association and a Board Member of the Millon Institute for Advanced Studies in Personality and Psychopathology. Dr. Strack is currently a staff psychologist at the VA Outpatient Clinic, and an instructor at the California School of Professional Psychology and Fuller Graduate School of Psychology, all in the Los Angeles area.