3 Traits Personality Assessments Can't Reveal

Personality testing is a common tool used to predict a job candidate's potential within a given role—but there are some traits no test can adequately uncover.

The Myers-Briggs Type Indicator (MBTI), one of several assessment tools used by HR to evaluate job candidates, has about as much validity as a BuzzFeed quiz.

It's "utterly meaningless," according to science reporter Joseph Stromberg, who wrote about the MBTI for Vox last month.

Many HR departments depend on personality tests, including the MBTI, to gauge a candidate's ability to sell, his openness to new experiences, leadership potential, or likelihood of fitting into an organization, among other things.

Nick Fabrizio, principal consultant with the Medical Group Management Association, prefers behavioral interviews to personality tests—but not all of his clients agree. "I have two for-profit healthcare system client that use personality testing," he says.

"They use the tests to make hiring decisions. Sometimes, they use them as a first cut, to screen out the first round of applicants after a first interview." He's seen both MBTI and the Big Five Personality Test used in these inventories.

As for what his clients are looking for, "It all depends on the job," he says. "If it's a physician who has to be more sales oriented, they assume introverts might not do as well in that field. But, if they're doing data analysis, that might be a fit."

But there are certain things that standardized personality assessments can't reveal.

1. A Candidate's Impact on Group Dynamics

Anticipating how well a candidate will fit in with a team and get along with coworkers is one of the main reasons for conducting a pre-hire personality test—but that's something these tests can't measure.

But, says Cheryl Oxley, a consultant with the corporate solutions team at Hogan Assessments, the test isn't going to tell you if your new guy is going to get on well with the team. "We do have a measure of social desirability," she says. Specifically, it "measures if someone is responding in a way the majority of the working adult population would."

Hogan offers a multiple-choice employee personality assessment which is used by 60% of Fortune 500 companies and about 20 healthcare systems to assess executives.

So, the test might be able to tell if a subject reacts in ways consistent with the norm, but not if he's going to get along with people.

Another thing these tests won't tell you: whether you're hiring a bully, a sociopath, psychopath, or a narcissist. "We don't get into the world of personality disorders," says Oxley, who adds that the tests also can't uncover propensities toward stealing, addiction, or personal integrity.

2. Whether the Subject Is Having A Bad Day

As if job interviews weren't stressful enough, taking any sort of multiple-choice test can summon unpleasant memories such as flashbacks to high school—especially if people feel they're being judged or "typed." Additionally, test results can be skewed if the subject is having personal problems which may change the way they might normally answer questions.

"When a subject is going through major life events like death, divorce, disease, there can be a dramatic shift in scores," admits Oxley.

Oxley suggests that if the test scores seem counter to what one would expect—especially if the candidate is well-known to the organization—the hiring manager or other person involved in the testing process may be able to discuss it with the candidate.

But a perfectly qualified candidate you've never met before who had an argument with a loved one the night before the test might answer questions such as, "I am a relaxed, easygoing person" or "I never worry about my past mistakes" differently after a stressful confrontation, than on a regular day.

3. The Candidate's Drive and Passion

No test can tell for certain how badly a candidate wants a job, or how badly he wants to succeed.

"The candidate [who received an undesirable score] might not be a poor fit all of the time—they'll just have a harder time getting up to speed or fitting into the company culture. They might experience greater challenges, depending on the organizational need. It doesn't mean they can't do the job… we're dealing with probabilities [of success], not possibilities," Oxley says.

MGMA's Fabrizio is less forgiving of the assessment's shortcomings. "I think a person's track record and their accomplishments are a better indication [of potential success within a role]." If a candidate got to the point where you are considering them, they got there for a reason, he adds—they don't need to take a personality test to show they are inclined to do the job.

These tests give a false sense of security that your incoming employees will fit in, do their jobs well, and be happy in their work. But, if you are properly conducting your interview process, you should already be fairly confident in your choices.

"I always ask organizations that are considering doing this, 'what do you hope to gain from it?' if you do a good job of screening a candidate, doing the reference checks, and using good, behavioral-based interviews, you'll already be way ahead of the game," recommends Fabrizio.