Personality is a potentially important predictor of work behavior. In job interviews, companies try to assess a candidate’s personality and the potential for a good match, but interviews are only as good as the people conducting them. In fact, interviewers are not particularly good at detecting the best trait that predicts performance: conscientiousness.
One method some companies use to improve this match and detect the people who are potentially good job candidates is personality testing. Several companies conduct pre-employment personality tests. Companies using them believe that these tests improve the effectiveness of their selection and reduce turnover. For example, Overnight Transportation in Atlanta found that using such tests reduced their on-the-job delinquency by 50%–100%.
Yet, are these methods good ways of employee selection? Experts have not yet reached an agreement on this subject and the topic is highly controversial. Some experts cite data indicating that personality tests predict performance and other important criteria such as job satisfaction. However, we must understand that how a personality test is used influences its validity.
Imagine filling out a personality test in class. You will probably fill it out as honestly as you can. Then, if your instructor correlates your personality scores with your class performance, we could say that the correlation is meaningful. But now imagine that your instructor tells you, before giving you the test, that based on your test scores, you will secure a coveted graduate assistant position, which comes with a tuition waiver and a stipend. In that case, would you still fill out the test honestly or would you try to make your personality look as “good” as possible?
In employee selection, where the employees with the “best” personalities will be the ones receiving a job offer, a complicating factor is that people filling out the survey do not have a strong incentive to be honest. In fact, they have a greater incentive to guess what the job requires and answer the questions in a way they think the company is looking for. As a result, the rankings of the candidates who take the test may be affected by their ability to fake. Some experts believe that this is a serious problem.
Others point out that even with faking the tests remain valid—the scores are related to job performance.
It is even possible that the ability to fake is related to a personality trait that increases success at work, such as social monitoring.
Scores on personality self-assessments are distorted for other reasons beyond the fact that some candidates can fake better than others. Do we even know our own personalities? Are we the best person to ask this question? How supervisors, coworkers, and customers see our personality may matter more than how we see ourselves. Therefore, using self-report measures of performance may not be the best way of measuring someone’s personality.
We have our blind areas. We may also give “aspirational” answers. If you are asked whether you are honest, you may think “yes, I always have the intention to be honest.” This actually says nothing about your actual level of honesty.
Another problem with using these tests is the uncertain relationship between performance and personality. On the basis of research, personality is not a particularly strong indicator of how a person will perform. According to one estimate, personality only explains about 10%–15% of variation in job performance. Our performance at work depends on many factors, and personality does not seem to be the key factor for performance. In fact, cognitive ability (your overall mental intelligence) is a more powerful predictor of job performance. Instead of personality tests, cognitive ability tests may do a better job of predicting who will be good performers. Personality is a better predictor of job satisfaction and other attitudes, but screening people out on the assumption that they may be unhappy at work is a challenging argument to make in an employee selection context.
In any case, if an organization decides to use these tests for selection, it is important to be aware of their limitations. If they are used together with other tests, such as tests of cognitive abilities, they may contribute to making better decisions. The company should ensure that the test fits the job and actually predicts performance. This is called validating the test. Before giving the test to applicants, the company could give it to existing employees to find out the traits that are most important for success in this particular company and job. Then, in the selection context, the company can pay particular attention to those traits.
Finally, the company also needs to make sure that the test does not discriminate against people on the basis of sex, race, age, disabilities, and other legally protected characteristics. Rent-a-Center experienced legal difficulties when the test they used was found to violate the Americans with Disabilities Act (ADA). The company used the Minnesota Multi phasic Personality Inventory for selection purposes, but this test was developed to diagnose severe mental illnesses; it included items such as “I see things or people around me others do not see.” In effect, the test served the purpose of a clinical evaluation and was discriminating against people with mental illnesses, which is a protected category under ADA.