| Personality test | |
|---|---|
 The four temperaments as illustrated by Johann Kaspar Lavater | |
| MeSH | D010556 |
A personality test is a method of assessing human personality constructs. Most personality assessment instruments (despite being loosely referred to as "personality tests") are in fact introspective (i.e., subjective) self-report questionnaire (Q-data, in terms of LOTS data) measures or reports from life records (L-data) such as rating scales.[1][2] Attempts to construct actual performance tests of personality have been very limited even though Raymond Cattell with his colleague Frank Warburton compiled a list of over 2000 separate objective tests that could be used in constructing objective personality tests.[3] One exception, however, was the Objective-Analytic Test Battery, a performance test designed to quantitatively measure 10 factor-analytically discerned personality trait dimensions.[4][5] A major problem with both L-data and Q-data methods is that because of item transparency, rating scales, and self-report questionnaires are highly susceptible to motivational and response distortion ranging from lack of adequate self-insight (or biased perceptions of others) to downright dissimulation (faking good/faking bad) depending on the reason/motivation for the assessment being undertaken.[6][7][8]
The first personality assessment measures were developed in the 1920s[9] and were intended to ease the process of personnel selection, particularly in the armed forces. Since these early efforts, a wide variety of personality scales and questionnaires have been developed, including the Minnesota Multiphasic Personality Inventory (MMPI), the Sixteen Personality Factor Questionnaire (16PF), the Comrey Personality Scales (CPS), among many others.[10][11] Although popular especially among personnel consultants, the Myers–Briggs Type Indicator (MBTI) has numerous psychometric deficiencies.[12] More recently, a number of instruments based on the Five Factor Model of personality have been constructed such as the Revised NEO Personality Inventory.[13] However, the Big Five and related Five Factor Model have been challenged for accounting for less than two-thirds of the known trait variance in the normal personality sphere alone.[14][15][16]
Estimates of how much the personality assessment industry in the US is worth range anywhere from $2 and $4 billion a year (as of 2013).[17] Personality assessment is used in wide a range of contexts, including individual and relationship counseling, clinical psychology, forensic psychology, school psychology, career counseling, employment testing, occupational health and safety and customer relationship management.
The origins of personality assessment date back to the 18th and 19th centuries, when personality was assessed through phrenology, the measurement of bumps on the human skull, and physiognomy, which assessed personality based on a person's outer appearances.[18] Sir Francis Galton took another approach to assessing personality late in the 19th century. Based on the lexical hypothesis, Galton estimated the number of adjectives that described personality in the English dictionary.[19] Galton's list was eventually refined by Louis Leon Thurstone to 60 words that were commonly used for describing personality at the time.[19] Through factor analyzing responses from 1300 participants, Thurstone was able to reduce this severely restricted pool of 60 adjectives into seven common factors.[20][19] This procedure of factor analyzing common adjectives was later utilized by Raymond Cattell (7th most highly cited psychologist of the 20th Century—based on the peer-reviewed journal literature),[21] who subsequently utilized a data set of over 4000 affect terms from the English dictionary that eventually resulted in construction of the Sixteen Personality Factor Questionnaire (16PF) which also measured up to eight second-stratum personality factors.[22] Of the many introspective (i.e., subjective) self-report instruments constructed to measure the putative Big Five personality dimensions, perhaps the most popular has been the Revised NEO Personality Inventory (NEO-PI-R)[19] However, the psychometric properties of the NEO-PI-R (including its factor analytic/construct validity) has been severely criticized.[23]
Another early personality instrument was the Woodworth Personal Data Sheet, a self-report inventory developed for World War I and used for the psychiatric screening of new draftees.[18]
There are many different types of personality assessment measures. The self-report inventory involves administration of many items requiring respondents to introspectively assess their own personality characteristics. This is highly subjective, and because of item transparency, such Q-data measures are highly susceptible to motivational and response distortion.[24] Respondents are required to indicate their level of agreement with each item using a Likert scale or, more accurately, a Likert-type scale. An item on a personality questionnaire, for example, might ask respondents to rate the degree to which they agree with the statement "I talk to a lot of different people at parties" on a scale from 1 ("strongly disagree") to 5 ("strongly agree").
Historically, the most widely used multidimensional personality instrument is the Minnesota Multiphasic Personality Inventory (MMPI), a psychopathology instrument originally designed to assess archaic psychiatric nosology.[25][26]
In addition to subjective/introspective self-report inventories, there are several other methods for assessing human personality, including observational measures, ratings of others, projective tests (e.g., the TAT and Ink Blots), and actual objective performance tests (T-data).
The meaning of personality test scores are difficult to interpret in a direct sense. For this reason substantial effort is made by producers of personality tests to produce norms to provide a comparative basis for interpreting a respondent's test scores. Common formats for these norms include percentile ranks, z scores, sten scores, and other forms of standardized scores.
A substantial amount of research and thinking has gone into the topic of personality test development. Development of personality tests tends to be an iterative process whereby a test is progressively refined. Test development can proceed on theoretical or statistical grounds. There are three commonly used general strategies: Inductive, Deductive, and Empirical.[27] Scales created today will often incorporate elements of all three methods.
Deductive assessment construction begins by selecting a domain or construct to measure.[28] The construct is thoroughly defined by experts and items are created which fully represent all the attributes of the construct definition.[28] Test items are then selected or eliminated based upon which will result in the strongest internal validity for the scale. Measures created through deductive methodology are equally valid and take significantly less time to construct compared to inductive and empirical measures. The clearly defined and face valid questions that result from this process make them easy for the person taking the assessment to understand. Although subtle items can be created through the deductive process,[29] these measure often are not as capable of detecting lying as other methods of personality assessment construction.[28]
Inductive assessment construction begins with the creation of a multitude of diverse items. The items created for an inductive measure to not intended to represent any theory or construct in particular. Once the items have been created they are administered to a large group of participants. This allows researchers to analyze natural relationships among the questions and label components of the scale based upon how the questions group together. Several statistical techniques can be used to determine the constructs assessed by the measure. Exploratory Factor Analysis and Confirmatory Factor Analysis are two of the most common data reduction techniques that allow researchers to create scales from responses on the initial items.[citation needed]
The Five Factor Model of personality was developed using this method.[30] Advanced statistical methods include the opportunity to discover previously unidentified or unexpected relationships between items or constructs. It also may allow for the development of subtle items that prevent test takers from knowing what is being measured and may represent the actual structure of a construct better than a pre-developed theory.[31] Criticisms include a vulnerability to finding item relationships that do not apply to a broader population, difficulty identifying what may be measured in each component because of confusing item relationships, or constructs that were not fully addressed by the originally created questions.[32]
Empirically derived personality assessments require statistical techniques. One of the central goals of empirical personality assessment is to create a test that validly discriminates between two distinct dimensions of personality. Empirical tests can take a great deal of time to construct. In order to ensure that the test is measuring what it is purported to measure, psychologists first collect data through self- or observer reports, ideally from a large number of participants.
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Further information on the matched series of timed cognitive aptitude tests: Morrisby Profile |
A personality test can be administered directly to the person being evaluated or to an observer. In a self-report, the individual responds to personality items as they pertain to the person himself/herself. Self-reports are commonly used. In an observer-report, a person responds to the personality items as those items pertain to someone else. To produce the most accurate results, the observer needs to know the individual being evaluated. Combining the scores of a self-report and an observer report can reduce error, providing a more accurate depiction of the person being evaluated. Self- and observer-reports tend to yield similar results, supporting their validity.[33]
Direct observation involves a second party directly observing and evaluating someone else. The second party observes how the target of the observation behaves in certain situations (e.g., how a child behaves in a schoolyard during recess). The observations can take place in a natural (e.g., a schoolyard) or artificial setting (social psychology laboratory). Direct observation can help identify job applicants (e.g., work samples[34]) who are likely to be successful or maternal attachment in young children (e.g., Mary Ainsworth's strange situation). The object of the method is to directly observe genuine behaviors in the target. A limitation of direct observation is that the target persons may change their behavior because they know that they are being observed.[35] A second limitation is that some behavioral traits are more difficult to observe (e.g., sincerity) than others (e.g., sociability). A third limitation is that direct observation is more expensive and time-consuming than a number of other methods (e.g., self-report).[33]
Though personality tests date back to the early 20th century, it was not until 1988 when it became illegal in the United States for employers to use polygraphs that they began to more broadly utilize personality tests.[36] The idea behind these personality tests is that employers can reduce their turnover rates and prevent economic losses in the form of people prone to thievery, drug abuse, emotional disorders or violence in the workplace. There is a chance that an applicant may fake responses to personality test items in order to make the applicant appear more attractive to the employing organization than the individual actually is.[37]
Personality tests are often part of management consulting services, as having a certification to conduct a particular test is a way for a consultant to offer an additional service and demonstrate their qualifications. The tests are used in narrowing down potential job applicants, as well as which employees are more suitable for promotion.[38] The United States federal government is a notable customer of personality test services outside the private sector with approximately 200 federal agencies, including the military, using personality assessment services.[38]
Despite evidence showing personality tests as one of the least reliable metrics in assessing job applicants,[39] they remain popular as a way to screen candidates.
There are several criteria for evaluating a personality test. For a test to be successful, users need to be sure that (a) test results are replicable and (b) the test measures what its creators purport it to measure. Fundamentally, a personality test is expected to demonstrate reliability and validity. Reliability refers to the extent to which test scores, if a test were administered to a sample twice within a short period of time, would be similar in both administrations. Test validity refers to evidence that a test measures the construct (e.g., neuroticism) that it is supposed to measure.[40]
A respondent's response is used to compute the analysis. Analysis of data is a long process. Two major theories are used here: classical test theory (CTT), used for the observed score;[41] and item response theory (IRT), "a family of models for persons' responses to items".[42][43] The two theories focus upon different 'levels' of responses and researchers are implored to use both in order to fully appreciate their results.
Firstly, item non-response needs to be addressed. Non-response can either be unit, where a person gave no response for any of the n items, or item, i.e., individual question. Unit non-response is generally dealt with exclusion.[44] Item non-response should be handled by imputation – the method used can vary between test and questionnaire items.
The conventional method of scoring items is to assign '0' for an incorrect answer and '1' for a correct answer. When tests have more response options (e.g. multiple choice items) '0' when incorrect, '1' for being partly correct and '2' for being correct.[44] Personality tests can also be scored using a dimensional (normative) or a typological (ipsative) approach. Dimensional approaches such as the Big 5 describe personality as a set of continuous dimensions on which individuals differ. From the item scores, an 'observed' score is computed. This is generally found by summing the un-weighted item scores.
In the 1960s and 1970s some psychologists dismissed the whole idea of personality, considering much behaviour to be context-specific.[45] This idea was supported by the fact that personality often does not predict behaviour in specific contexts. However, more extensive research has shown that when behaviour is aggregated across contexts, that personality can be a mostly good predictor of behaviour. Almost all psychologists now acknowledge that both social and individual difference factors (i.e., personality) influence behaviour. The debate is currently more around the relative importance of each of these factors and how these factors interact.
One problem with self-report measures of personality is that respondents are often able to distort their responses.[46]
Several meta-analyses show that people are able to substantially change their scores on personality tests when such tests are taken under high-stakes conditions, such as part of a job selection procedure.[47][48]
Work in experimental settings[49] has also shown that when student samples have been asked to deliberately fake on a personality test, they clearly demonstrated that they are capable of doing so. Hogan, Barett and Hogan (2007)[50] analyzed data of 5,266 applicants who did a personality test based on the Big Five. At the first application the applicants were rejected. After six months the applicants reapplied and completed the same personality test. The answers on the personality tests were compared and there was no significant difference between the answers.
So in practice, most people do not significantly distort. Nevertheless, a researcher has to be prepared for such possibilities. Also, sometimes participants think that tests results are more valid than they really are because they like the results that they get. People want to believe that the positive traits that the test results say they possess are in fact present in their personality. This leads to distorted results of people's sentiments on the validity of such tests.
Several strategies have been adopted for reducing respondent faking. One strategy involves providing a warning on the test that methods exist for detecting faking and that detection will result in negative consequences for the respondent (e.g., not being considered for the job). Forced choice item formats (ipsative testing) have been adopted which require respondents to choose between alternatives of equal social desirability. Social desirability and lie scales are often included which detect certain patterns of responses, although these are often confounded by true variability in social desirability.
More recently, Item Response Theory approaches have been adopted with some success in identifying item response profiles that flag fakers. Other researchers are looking at the timing of responses on electronically administered tests to assess faking. While people can fake in practice they seldom do so to any significant level. To successfully fake means knowing what the ideal answer would be. Even with something as simple as assertiveness people who are unassertive and try to appear assertive often endorse the wrong items. This is because unassertive people confuse assertion with aggression, anger, oppositional behavior, etc.
Research on the importance of personality and intelligence in education shows evidence that when others provide the personality rating, rather than providing a self-rating, the outcome is nearly four times more accurate for predicting grades.[51]
The MBTI questionnaire is a popular tool for people to use as part of self-examination or to find a shorthand to describe how they relate to others in society. It is well known from its widespread adoption in hiring practices, but popular among individuals for its focus exclusively on positive traits and "types" with memorable names. Some users of the questionnaire self-identify by their personality type on social media and dating profiles.[52] Due to the publisher's strict copyright enforcement, many assessments come from free websites which provide modified tests based on the framework.[38]
Unscientific personality type quizzes are also a common form of entertainment. In particular Buzzfeed became well known for publishing user-created quizzes, with personality-style tests often based on deciding which pop culture character or celebrity the user most resembles.[53]
There is an issue of privacy to be of concern forcing applicants to reveal private thoughts and feelings through his or her responses that seem to become a condition for employment. Another danger is the illegal discrimination of certain groups under the guise of a personality test.[54]
In addition to the risks of personality test results being used outside of an appropriate context, they can give inaccurate results when conducted incorrectly. In particular, ipsative personality tests are often misused in recruitment and selection, where they are mistakenly treated as if they were normative measures.[55]
New technological advancements are increasing the possible ways that data can be collected and analyzed, and broadening the types of data that can be used to reliably assess personality.[56] Although qualitative assessments of job-applicants' social media have existed for nearly as long as social media itself, many scientific studies have successfully quantized patterns in social media usage into various metrics to assess personality quantitatively.[56] Smart devices, such as smart phones and smart watches, are also now being used to collect data in new ways and in unprecedented quantities.[56] Also, brain scan technology has dramatically improved, which is now being developed to analyze personalities of individuals extremely accurately.[56]
Aside from the advancing data collection methods, data processing methods are also improving rapidly.[56] Strides in big data and pattern recognition in enormous databases (data mining) have allowed for better data analysis than ever before.[56] Also, this allows for the analysis of large amounts of data that was difficult or impossible to reliably interpret before (for example, from the internet).[56] There are other areas of current work too, such as gamification of personality tests to make the tests more interesting and to lower effects of psychological phenomena that skews personality assessment data.[56]
With new data collection methods comes new ethical concerns, such as over the analysis of one's public data to make assessments on their personality and when consent is needed.[56]
Different types of the Big Five personality traits: