Assessing an applicant’s personality as part of the employment process has considerable appeal. It stands to reason that a person who shows up regularly, expends effort, and takes pride in the quality and quantity of work performed will be regarded as a more successful employee than one who does not do these things. Recent research on the impact of personality on job performance has focused on five personality factors: Extraversion, Emotional Stability, Agreeableness, Conscientiousness, and Openness to Experience.
Items are usually presented in multiple-choice format. Personality Tests have some resemblance to “clinical” tests.
It seems reasonable that if we could gain insight into an applicant's personality in terms of the above factors, we would be in an excellent position to predict his/her job performance.
First, the good news. There has been little or no minority impact reported in personality test scores.
However, on average, personality tests do not appear to work nearly as well to predict job performance as tests of General Mental Ability (GMA), Work Sample Simulations, or even Biodata. It is surprising, as well as disappointing, that only one of the above-listed five factors has shown consistent relationships with job performance. That factor is Conscientiousness. Reported validity coefficients for Conscientiousness has generally ranged from .10 to .30. These values are often significant and can be useful, but represent considerably less utility to an employer than the other types of tests.
There is another problem. Personality tests, particularly those measuring Conscientiousness, are relatively easy to fake. It is often obvious to applicants which responses would be viewed favorably by employers. Additional research has verified that at least some applicants in fact distort their responses on such tests. There have been attempts to adjust test scores to minimize or eliminate the effects of response distortion. But these have had limited success. Therefore, if you make selection decisions based on a personality test or Biodata scale, you may well hire applicants who have determined what responses will put them in the most favorable light.
To summarize, tests of Conscientiousness predict job performance, but not nearly as well as tests of GMA or Work Sample Simulations. Tests of other personality factors have shown little or no relationship. Disparate impact is minimal, which is a strong plus. However, there is evidence that applicants can and do distort their responses to make a favorable impression.