How Accurate Are Personality Assessments?

​Editor's Note: This article has been updated to note that the makers of the DiSC assessment don't recommend it for pre-employment screening.

When the Piedmont Family YMCA in Charlottesville, Va., was recently recruiting for a new finance director, time was of the essence. The organization was on the brink of an audit, and the executive team didn’t have a firm handle on the financial records or processes.

The HR team members knew what hard skills would send a resume to the top of the pile, but they also wanted to quantify the softer side of what they were seeking. They asked final candidates to take the DiSC, a personality assessment that scores subjects on four different traits: dominance, influence, steadiness and conscientiousness.

“We had to hire for skill, but the personality test allowed us to hire someone with just the right amount of enthusiasm and collaboration to balance out their analytical parts,” says Sarah Wiegman, the organization’s former HR director. The company wanted “someone who would get how and why to explain a profit-and-loss statement in a way that other people would get.”

Although the top candidates might have looked nearly interchangeable based on their analytical skills, the personality assessment helped narrow the field considerably, Wiegman says.

As a result, the organization expanded its use of the personality assessment to finalists for all open positions.

“There’s no question that the fit of new hires has improved, as well as the culture and engagement around the hiring process,” Wiegman says. “We consider this part of the hiring phase a must-do now.”

Advocates of assessments claim the tools can reduce turnover by identifying candidates who are a better fit, while limiting unconscious bias on the part of hiring managers. Organizations that have been quick to integrate assessments often report that capturing a more complete, or “whole person,” snapshot of a candidate can mean the difference between hiring someone who thrives over the long term and someone who aces the interview but then founders in the role.

Critics argue, however, that assessments may be keeping great candidates from advancing in the hiring process, by measuring and prioritizing traits that don’t strongly correlate to success in the specific position.

For example, the DiSC assessment is popular because it's inexpensive and easy to use, says Phyllis G. Hartman, owner of PGHR Consulting Inc. in Pittsburgh. But she notes that the DiSC website states that it's not recommended for pre-employment screening "because it doesn't measure a specific skill, aptitude or factor specific to any position."

Even Wiegman is quick to point out that these tools are only as valuable as the HR professionals wielding them.

“If you bring someone into a team because you think you need someone who’s a real driver with their personality, and what the team actually needs is someone who can inspire and influence people to want to make changes, well, the assessment helped you find what you wanted—but you still have a bad hire,” she says. “What good is that?”

A Growing Trend

Technology’s recent disruption of all things HR has meant an exponential rise in the number of assessment offerings—as well as the methodologies and algorithms underpinning them.

SquarePeg, for example, asks job seekers and HR professionals a series of questions around personality traits and behavior preferences before referring matches to one another. Traitify, which was developed by psychologists, sells its digital assessment tools to companies looking for a faster, more effective alternative to the Myers-Briggs Type Indicator, which isn’t intended for use in screening job candidates. Pymetrics promises to use neuroscience games and black-box artificial intelligence to accurately assess what a company’s top performers have in common, and then find candidates with similar personality traits and behavior tendencies.

A 2017 survey from the Society for Human Resource Management found that nearly one-third (32 percent) of respondents were using personality and behavior assessments when filling executive-level roles, and 28 percent of respondents deployed them for middle-management openings. For nonmanagement roles, 20 percent incorporated assessments as part of the hiring process.  

Fixed vs. Fluctuating

In the burgeoning market of assessments, HR professionals who are being marketed to on all fronts must first gain command of the lingo. A behavior test measures factors that are observable—such as verbal ability or reaction times, says Alexander Swan, assistant professor of psychology at Eureka College in Eureka, Ill., who has conducted research on assessments.

“A personality test, on the other hand, measures characteristics of a person, such as being intuitive,” he says. “Are you outgoing and sociable, or do you prefer to spend most of your time alone? We can measure the level of extroversion through a personality assessment.”

Both types of tests can hold insights about the individual, but it’s important to understand that personality tends to be fixed and stable, while behavior is more likely to change over time.

“As an example, if Jane derives energy from people interactions and not from detailed work, she might have learned to implement processes to help assure her attention to detail and to allow her to succeed in that area well enough for a position that requires some detail work,” says Leslie Andrus, SHRM-SCP, HR director at Seraphic Group in Charlottesville, Va.

So, for a position that requires some detailed work, discounting her from the candidate pool based solely on an assessment would be an error. But if the position required little to no interaction with other people, that’s a larger red flag that her personality might not be a great fit for the role.

Charles Gerhold, lead consultant at 3D Group, a management consulting company in Emeryville, Calif., that helps companies implement and interpret various hiring assessments, agrees that it’s important not to confuse personality and behavior.

“Don’t be foolish and ignore the role that development can play in shaping someone’s behavior,” he says. “You’ll do that person a disservice and limit their career.”

When companies implement personality assessments, he recommends that they also pair those findings with some sort of “behavior capture,” whether that means a situational interview for external candidates or 360-degree feedback for internal candidates seeking a promotion.

For example, job candidates could be asked to describe a time they felt overwhelmed by work. What steps did they take to prioritize or make sure nothing slipped through the cracks?

“Structured interviews with good behavioral questions can be really revealing of how a person actually behaves,” he says. “And the best predictor of future behavior is truly past behavior.”

Amy Scher, SHRM-CP, HR manager at real estate investment company HayMax Capital LLC in Grand Junction, Colo., says the assessment-interview combination yields great hires.

It’s often difficult to cut through the scripted responses that many candidates come ready to provide in an interview. “These tests give us actual data that shows the probability of a fit based on their values and ours,” she says.

As an HR department of one, Scher opted for the Harrison Assessment, a customized test that measures 12 different behavior pairs (such as self-confidence and consideration for others) through 175 questions that take about 25 minutes to answer.

There’s no one-size-fits-all for what makes a great hire for the company, Scher says. Rather, she compares results for individual candidates against the personality and behavior targets for specific roles—and factors in responses candidates gave during interviews—before making any hiring recommendations.

Bias, Beware

While some argue that such assessments can reduce hiring bias, federal regulators say they can have a discriminatory effect. Last year, Best Buy and CVS Caremark reached agreements with the U.S. Equal Employment Opportunity Commission (EEOC) to stop using their personality assessments after investigations found they likely adversely impacted applicants based on race and national origin. In 2015, Target agreed to pay $2.8 million to resolve a charge that its use of personality tests during pre-employment screening violated the Americans with Disabilities Act.

“The major legal risk from these tests, when used in hiring, is disparate impact discrimination claims,” says Jonathan Crotty, a partner at Parker Poe law firm in Charlotte, N.C.

“Applicants or the EEOC can contend that the tests are biased against people in protected classifications—such as race or gender—under federal anti-discrimination laws,” he says. “That means making employment conditional on achieving certain test outcomes would result, over time, in fewer applicants in the protected classifications being chosen than if the tests weren’t being used.”

A vendor’s assurance that the tool isn’t biased won’t cut it as a legal defense. For an assessment to be safely implemented as a hiring tool, it must be statistically validated—or a company leaves itself vulnerable to unintentional bias, Crotty says.

“For example, men and women may score differently on a broad statistical basis on personality tests, based on the way the questions are written,” he says. If these differences are statistically significant, using the test “could violate the EEOC’s regulations on tests and selection procedures.”

If the test has a disparate impact—disproportionately screening out a certain type of person—the employer has to be able to justify its use on the basis of business necessity.

“But for things like personality tests, it can be hard to show that it was that important in the selection process,” he says.

Gerhold cautions against rushing into selecting a vendor. In addition to asking whether the assessment has been validated, HR professionals also should ask by who and on which populations.

“Are the mean scores similar or the same for men and women, for those over and under 40, for people of different races and national origins?” he suggests asking. “If not, using the assessment isn’t ethical and your company could get in serious trouble.”

It’s worth noting that there are many assessments that have been proved to hold steady across different protected classes. The Hogan Personality Inventory Assessment is just one better-known example. For a study published in Personnel Psychology, Deniz Ones, a professor of industrial psychology at the University of Minnesota in Minneapolis, pooled hundreds of studies that looked at personality assessments and bias. Overall, her research shows, there were no consistent race and ethnicity differences on these measures.

“But just like any product used by HR professionals, there are professionally developed tests that are excellent and there are ones that have been put together with little psychometric and statistical expertise. It’s buyer beware,” she says.

A strong—and fair—test takes both psychological and psychometric expertise to develop, and the process to develop and refine the test can often take several years, she says. “The questions and the test itself must go through a series of statistical hurdles and checks on fairness before they can be finalized,” she says.