If Personality is So Important, Why Shouldn’t We Hire for It?

Employers both large and small have embraced personality testing as a highly useful tool that can help them understand their employees better. 

Among the organizations that use personality testing, a subset are using it to help them make actual hiring decisions. In a 2017 study conducted by the Society of Human Resource Management, 32% of HR professionals reported using personality assessments when filling executive roles, with 28% saying they did the same when filling middle-management positions. In a more recent (2024) survey from the same organization, 14% of HR professionals said they relied on pre-employment personality assessments to help them make hiring decisions, often as part of a battery of tests designed to determine potential employee fit. 

Personality testing offers fascinating insights into an individual’s psychological and emotional profile. It can disclose important details about the way someone thinks and reacts in the workplace, and suggest a person’s optimal working style and work environment. But what it cannot do is predict the way a person will perform in a specific job—or determine whether they are qualified for that job in the first place.

Giving personality test results significant weight during the hiring process is a problematic practice. Many hiring managers are doing so, but you would be wise to think twice before following their example, for reasons that will be discussed below.

The Problem of Using Personality Tests in Hiring

Scientifically validated personality tests like Truity’s DISC, Big Five and the Myers-Briggs-based TypeFinder® provide in-depth descriptions of people’s core personality traits. As such, they provide employers with a collection of additional data points to consider while evaluating job candidates with similar levels of skill and experience. 

The insights they offer potentially can reveal more than a carefully crafted resume or canned answers to interview questions, which is precisely why employers like them. In the 2024 SHRM survey mentioned above, 78% of HR professionals said that using personality assessments had improved their company’s hiring practices—though it’s important to note that they were often administered alongside work simulation tests, cognitive ability tests and other assessments, so it’s hard to know how much weight a personality test, on its own, is carrying.

In reality, there are good reasons to be skeptical about the usefulness of personality testing as a hiring tool. They downsides of this practice include:

1. A lack of evidence in support of its effectiveness

If you’ve chosen someone with a particular personality type to fill a role or receive a promotion, and that individual performs well, your natural inclination will be to credit the personality test that identified this high-performer. This might seem like a validation of pre-employment personality assessments, especially if this experience is repeated more than once.

But this type of “evidence” is based on unproven assumptions and can therefore be misleading. For all you know, other factors may have played a bigger role in that employee’s success than personality type—which is exactly what the research suggests.

According to multiple studies, no characteristic is more closely associated with success in the workplace than Conscientiousness, the Big Five trait associated with organization, responsibility and hard work. But in these studies, Conscientiousness only accounted for about 20% of the difference between high and low performers. The remaining 80% was explained by other factors, none of which could be linked to a specific personality type or trait. 

And other personality traits had even less predictive value than Conscientiousness, showing how difficult it is to correlate personality test results with long-term career success.

2. The risk of introducing unconscious bias to the hiring process

When evaluating potential employees based on personality, hiring managers will be making judgments about which characteristics they believe are most likely to predict job success or culture fit. This adds a degree of personal bias to the process, since even the most responsible HR professionals are likely to rank specific traits higher or lower according to their own standards and preferences.

For example, an Extraverted manager who credits their outgoing nature for their success may tend to favor candidates who share that characteristic, ignoring the qualifications of a talented and experienced Introvert. Similarly, a highly logical Thinking type, like an INTP in the 16-type system, might be reluctant to hire an otherwise highly qualified Feeler (F) candidate, if they were up for a position where emotional reactions could interfere with rational decision-making.

These biases are understandable, and don’t imply malice or a lack of professionalism; they simply reflect the human tendency to seek comfort in the familiar. However, when left unchecked, this “affinity bias” can cause a hiring manager to unconsciously discriminate against skillful and well-prepared individuals, and create a homogenized workforce that lacks cognitive diversity. By over-valuing specific personality markers that mirror their own, hiring managers risk building teams that share the same blind spots, ultimately stifling the very innovation and problem-solving they were hoping to recruit.

3. Job candidates bending the truth to improve their chances

Personality tests are constructed on the assumption that test-takers will be as honest as possible when answering questions. This is what makes the results valid and repeatable. When taking these tests voluntarily, or in low-pressure situations, most people will do their best to provide accurate information—they have no incentive to lie. But when a job or promotion is at stake, everything changes.

Researchers have discovered that 30% to 50% of job applicants will be less than fully honest when taking pre-employment personality tests, by customizing their answers to make a more favorable impression. In times when jobs are harder to come by, this number rises to an astonishing 82%, as revealed by studies carried out during the economic recession of 2008-2009.

This last statistic is especially relevant to the current mood. A Gallup survey taken in late 2025 revealed that just 28% of job seekers ages 18-34 were optimistic about finding a job anytime soon, a 40% drop in sentiment compared to the previous year. The well-publicized impact of AI on job prospects is only adding to the pessimism, creating even more powerful incentives for candidates to misrepresent themselves when taking personality tests.

4. Personality testing was not designed for this purpose

This is the most fundamental reason to reconsider the use of personality assessment in the hiring process—it’s not what they were designed for. These tests were built to measure thinking and behavioral patterns, emotional reactions and tendencies, personal values, approaches to relationships, preferred communication styles, and other aspects of what ultimately comprises an individual’s personality.

All of this has clear relevance to how someone will function in the workplace. But what personality tests cannot predict whether someone will fail or succeed in a particular job or work role, because that was never their purpose. Even the DISC assessment, which measures personality specifically in the workplace, is designed to empower a person by increasing their self-awareness, which should help them succeed no matter which career they choose. 

If you allow personality test results to influence your hiring decisions, you’ll be adding an extra layer of meaning to those results beyond what the test creators intended. Personality assessments are rooted in extensive research into human personality, not personal opinion about their meaning, which is why you should proceed with extreme caution before using them in a non-evidence-based manner.

Personality Testing Can Helpful—If You Use it Right

There are strong arguments in favor of using personality testing in the workplace. For instance, personality test results can help explain: 

• Why your company’s employees are peak performers in some moments, and mediocre or even underachieving in others.
• Which team members should fill which roles to ensure maximum productivity.
• The type of workplace environment that will make everyone feel comfortable and confident to perform their best work.
• Why communication is breaking down, and what interventions can help team members get on the same page.

When used thoughtfully, personality tests can help managers understand how to support different working styles. They can team fit, day-to-day collaboration and conflict resolution without being treated as a verdict on someone’s value or ability. Taken this way, personality testing is at its most useful when it helps people work better together, not when it is used to make rigid decisions about who should or should not be hired.