A book on the history of the Myers-Briggs Type Indicator (MBTI) made waves back in 2018 by putting the media into a feeding frenzy over the accuracy and validity of personality assessments. This criticism specifically extended into the popular use of personality testing for careers and their HR applications. As we’ve seen before, the feedback tended to fall into one of three generic claims:
- Hiring personality tests are biased and discriminatory
- They aren’t relevant for the job
- They simply fail to predict performance
Many articles that came from this discussion echoed these themes, going so far as to state that many of the benefits of personality tests are actually myths. However, the talking points raised in this discussion seem to miss one critical detail: It’s difficult, but necessary, to distinguish scientifically proven, reliable tools from those that are of poor quality.
So, should personality tests be used for hiring?
Yes, and here’s why.
Contrary to what these articles are claiming, high-quality personality assessments do, actually, predict performance, surpassing the quality of alternative, more traditional talent acquisition methods such as resumés and interviews. For these reasons and more, there are clear advantages of using personality tests in the hiring process — so why does controversy still exist? The true criticism of personality assessments actually stems from the widespread popularity of inexpensive, ‘trendy’ tools that lack science-based conclusions.
In a flooded market of personality tests that claim to be accurate, how can you know which assessments are truly effective? In short, looking at the validity and reliability of an assessment tool.
Validity
Validity indicates the predictive ability of an assessment by measuring the correlation of one thing with another, such as the correlation of personality with job performance.
To break it down, validity is measured with a coefficient between 0 and 1 (absolute value). The closer to one, the more accurate the predictive power of the assessment. A robust assessment tool, such as the Hogan Assessment suite (HPI, HDS, and MVPI) has a predictive validity of .54. Comparatively, the structured interviewing of candidates has a predictive validity of only .18.
In other words, validity is a measure of accuracy.
Reliability
Reliability, on the other hand, can tell you if the assessment can properly measure the same thing time and time again. The reliability of an assessment can be evaluated in two broad ways: 1) internal consistency and 2) test-retest reliability.
Internal consistency relates to the questions that are used in each assessment; by asking a question in a few different ways, the tester helps ensure that the assessment is getting an accurate measurement of the concept.
Test-retest reliability is a measure of the consistency of responses over time. Are people responding to questions the same way each time they take the test? Inconsistent responses can indicate that assessments results are not actually measuring personality, which should be relatively stable over time.
To put it plainly, reliability is a measure of consistency.
While there’s no doubt that, in some cases, there are pros and cons of personality tests, it’s important to make the distinction between tests that are ‘flashy’ and those that are science-based. In your search for a high-quality assessment tool, pay close attention to the following topics to ensure efficacy:
- Validity and reliability — Ask the vendor for information on the reliability and predictive validity of their assessments. These two things can tell you if the assessment is accurately and consistently measuring what they say it does.
- Scientific background — Quality assessment tools should be heavily researched and built on a sound theoretical framework. If this information is not readily available, there’s a good chance the quality of that assessment is poor.
- Accordance with employment guidelines — Many countries have employment guidelines to protect employees from discrimination. Any assessment used for recruitment purposes should demonstrate how they follow those guidelines.
- Predictive ability for job performance — Often, assessments feature questions that measure identity or self-perception of oneself, which can often be flawed. A better approach is to use objective measures of reputational factors that predict performance.
- Adaptability for different cultures/languages — Be sure to find out if an assessment is adapted to your specific language and culture. Proper translation is important but not sufficient to account for all cultural differences.
The next time you hear someone highlight the problem with using personality tests for hiring, urge them to look deeper into the options available and equip them with the means to properly vette an assessment tool. As Adrian Furnham, internationally acclaimed management expert and Professor of Psychology at University College London emphasizes:
“There are two criteria for a good assessment: evidence of test validity and quality of feedback on questionnaire. It should be useful for the employer and the employee alike: It measures clearly what you need it to measure; it is clear and straightforward for the respondent; the test has considerable evidence of reliability and validity, and the employee gets rich and useful feedback. In my experience, the three Hogan measures (HPI, HDS and MVPI) are the ones that have proved to be the most effective, because of the above reasons.”
