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Personality is the driving force behind human behavior. At Hogan, we eat, sleep, and breathe personality psychology. We study the science of personality, we’ve pioneered the use of personality tests to improve workplace performance, and our tests evaluate all aspects of personality: the bright side, the dark side, and the inside. But we also understand that not everyone knows personality like we do, and that’s why we put together this guide to help you develop your expertise.

What is personality?

While there are many definitions of personality, our perspective on the subject derives from socioanalytic theory, which integrates interpersonal theory with evolutionary psychology.

Socioanalytic theory assumes that human nature is characteristically social. People always live in groups, which always have a hierarchy with a well-defined structure of power and a leader. People need to have a system of meaning, such as religion, philosophy, or science, that helps them make sense of the world. As a consequence of these three things, people will always have three main motives: getting along with others (i.e., cooperation), getting ahead of others (i.e., competition), and finding meaning. Personality is what determines how people work toward those goals and the extent to which they achieve them.

More specifically, three components of personality shape our interactions: identity, reputation, and social skill. Identity is the story we tell ourselves about ourselves—it’s the person you think you are. While there might be some takeaways in how we perceive ourselves, we are usually wrong. We often have an inflated idea of our own talent, or we might be unnecessarily hard on ourselves.

Reputation, on the other hand, is what everyone else thinks of us, and it’s based on our overt behaviors and social skills. Your reputation is the person other people think you are. Your success in the workplace is dependent on your reputation, and this is the part of personality that the best personality tests are based on.

Does personality change over time?

If changes to someone’s personality do occur, they happen very slowly. Individual behavior can change on a day-to-day basis, but personality refers to behavioral patterns that we see consistently over time.

It’s helpful to think about the following analogy about the weather to describe personality changes. While we can’t predict daily weather very accurately, we have an idea of what’s likely to happen. It’s much easier to predict regional and seasonal weather patterns. Like the daily weather, behavior can change moment to moment and context to context. But personality is more like the regional and seasonal weather, where it takes time to see change.

Think about development coaching. You have a reputation for behaving a certain way, but through coaching, those behaviors can change. It’s just going to take time before others notice, and those changes aren’t going to deviate much from your natural tendencies. Personality is quite stable; that is, people do not change very much once they reach a certain age.

Scores from personality tests also can be quite stable when the assessment is well constructed. A person retaking a quality personality test will get very similar results most of the time, while retaking a poorly made personality test can have dramatically different results. But just like scores on many other types of tests, including cognitive ability tests and certain medical tests (e.g., blood pressure), personality assessment scores can fluctuate, even over short intervals.

At Hogan, we’ve found that fluctuating scores on reassessments typically fall within two points of the original assessment score. This degree of variation does not usually affect the interpretation of the overall personality profile. In fact, when these changes do occur, they tend to be a result of a change in methodology and not reflective of a change in the individual.

How are personality tests made?

At Hogan, we spend a great deal of time thinking about the difference between identity and reputation when we build our personality assessments.

Identity, or how we think about ourselves, is frequently changing and often self-serving, and that makes it a poor basis for building personality assessments.

Reputation, or how others think about us, is often more stable and a more useful way to build personality assessments that predict job performance. The best predictor of future behavior is past behavior. Because reputation reflects past behavior, reputation is the best predictor of future behavior.

We validate our assessments by having people take those assessments. Then we ask other people who know them, such as peers, direct reports, and managers, to describe what they’re like. The assessment data and observer ratings—along with job performance review data, objective performance data, and 360-degree data—are stored in a database with personality data from several million people. Once someone has taken our assessments, we can use the information from our database to predict whether the person will be able to do a job, how they will behave on the job, and even whether they will like the job.

How do personality tests predict job performance?

Personality assessments should measure personality from the perspective of reputation, which is how others are likely to describe or experience us. Reputation is a collection of past and present behaviors described by others, and we know it to be the best predictor of future job performance. We have found that personality helps us to describe the characteristics and behaviors that are required for or important to job performance—things like resiliency and strategic self-awareness and collaboration.

Hogan’s personality tests are based on decades of research on personality psychology and measurement, and they have been validated against external criteria, including job performance and peer ratings. This allows us to describe the reputation that a job candidate likely has in the workplace.

We also compare the way a job candidate scores to thousands of other people to determine how that person will likely behave at work. Using custom research involving job analysis, we can also create personality profiles to determine how well candidates will fit into a particular job role or organizational culture.

Are personality tests accurate? What is validity?

In the case of personality assessments, a good tool can predict how well someone will perform their job. Not all personality assessments are accurate. Because the assessment industry is largely unregulated, many personality assessments on the market do not measure what they claim.

personality tests

There are two main questions that determine whether an assessment can deliver accurate results. Does it measure what it’s designed to measure? And does it measure it consistently? In short, accuracy requires evidence of validity and reliability. There are many types of validity. Criterion validity is the best type of validity to use for personality tests. Criterion validity refers to the accuracy of predicting a desired outcome. So in the case of personality tests, the outcome is predicting performance in specific jobs. Reliability refers to the consistency of the measurement. One way that you can evaluate this consistency is with test-retest reliability. Test-retest reliability refers to consistency of measurement across multiple test administrations. For example, using a ruler to measure height will produce the same measurement every time. That’s because a ruler is a reliable measure of height. We want our personality assessments to function in the same way.

At Hogan, we take pride in the validity and reliability of our assessments; they have a proven track record of predicting job performance.

Do personality tests discriminate or violate privacy?

We believe that personality assessments should be valid and fair to every job candidate and we have worked hard over the past three decades to democratize access to employment. Our validation research meets the highest professional standards, which means our assessments provide equal opportunity based on occupational qualifications and have no adverse impact on the candidate.

Broad research on personality has been conducted around the globe. When we look at that research, it shows that people are quite consistent. There aren’t really meaningful differences—based on things like age, gender, or ethnicity—in how individuals score on well-validated and accurate assessments.

The Hogan assessments are used to predict and measure workplace-related outcomes. They’re not diagnostic or clinical tools, which means we don’t use them to identify or diagnose any sort of clinical disorders. Because of that, and because they are well-constructed and valid instruments, they comply with all industry and professional regulations and don’t violate the Americans with Disabilities Act.

Hogan’s researchers spend a lot of time and effort ensuring that our assessments are predictive of the workplace outcomes we care about, applicable to a broad audience, and noninvasive.

Can people fake personality tests?

Despite the name, personality tests are not actually tests but rather an assessment of an individual’s personality. That means that there are no right or wrong answers, so faking is extremely difficult. When you answer a personality question, it’s actually a consideration of job fit. Do you fit with that job?

Another thing to consider is what experimental studies on faking tell us. When people are instructed to fake an assessment for a particular job deliberately, they get different scores than they would have gotten by answering honestly. But in the real world, when someone is actually trying to apply for a particular position, faking has no impact whatsoever on the person’s overall scores. That is, the person won’t get better job-fit scores.

In fact, in studies we’ve done here at Hogan, we’ve found that people who try to fake on personality assessments often get worse job-fit scores than they would have gotten if they had just applied for the job and taken the assessment in a more natural way.

In sum, the big picture on faking is that it’s not really an issue for personality assessments.

How can businesses use personality tests?

Talent acquisition and talent development are two primary applications for personality tests in the workplace.

Organizations can use personality tests to determine if candidates have the key personality characteristics to be successful in a job and if they fit the company culture. Assessments can also be used to uncover performance risks, improve interview techniques, and compare candidates side by side.

In industries that have a high risk of injuries and accidents, such as construction or oil and gas, safety assessments can be used for preselection. This allows companies to hire the right people to develop a culture of occupational safety.

For talent development, personality assessments can be used to identify employees’ strengths and weaknesses. Personality tests can encourage employees to take proactive steps to improve performance and help employees avoid career derailment.

What are the benefits of using a personality test?

Personality tests have many benefits for employment decisions, including identifying a match with core competencies and reducing bias in hiring.

First of all, the core competencies for most jobs are linked to personality characteristics, and a well-constructed assessment can measure those. This can be beneficial for hiring decisions as well as performance management. The benefits of hiring the right candidates and promoting the right employees can help an organization to improve its business outcomes—for example, by increasing the bottom line and reducing turnover.

Second, while there are many valid ways organizations can identify and develop talent, personality assessments offer the unique benefit of reducing the impact of bias on personnel decisions. Personality assessments are less discriminatory than classic evaluation methods, such as interviews and cognitive assessments. By reducing the impact of bias on employment decisions, personality assessments can also promote increased diversity, equity, and inclusion in the workplace.

How can you assess a personality assessment?

You don’t have to go too deep into the science to assess a personality test. There are three things to consider: job relatedness, reliability, and validity.

Job relatedness is an important scientific and legal standard that helps determine whether an assessment measures what is important for success on the job. Job relatedness is established through the process of job analysis. The assessment provider should be able to explain how the job analysis process works and how the process supports the use of the provider’s assessments for specific purposes.

The second factor to consider is reliability, which refers to the consistency of the assessment. Does the assessment reliably measure the same thing each time? This is what ensures that the results you get from the assessment aren’t a one-off. If the assessment is supposed to measure enduring characteristics, such as extroversion, it should be able to measure the same level of those characteristics each time. Ask the assessment provider to provide evidence of the assessment’s reliability.

The third factor to consider is validity, which refers to the accuracy of the personality test. Does the test measure what it’s supposed to measure? A valid assessment is one that helps you make accurate predictions. Just like with reliability, you should ask the assessment provider for documented scientific evidence that the assessment will help you make the predictions you need to make.

Finally, while making your evaluation, remember that decisions made using assessment results affect people’s lives for better or worse.

How can personality tests help you?

Put most simply, using personality tests will help your business understand people. Personality tests can be used for nearly all of your talent management needs. They can help you identify the right person for the job at any organization level, avoid bad hires, and facilitate employee and leadership development. Research has shown that personality tests help improve employee performance, increase profits, reduce turnover, promote higher customer satisfaction, and more.

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