Personality strength – the hidden ingredient to better personality assessments

Personality consistently predicts job-performance, but the way it is measured may not be sufficient enough to answer the question it seeks out to answer, as it only looks at average behavioral tendencies. In this post we will show you how to improve your personality assessment by incorporating elements of personality strength.

Using a dynamic approach to personality, this post will aim to give you a deeper understanding on how personality works in a work context, how you can improve your personality assessment procedure, and how knowledge of personality can help your employees grow into their job.

Specifically we will take a close look at:

  • The modern perception on personality (i.e. personality as a dynamic entity),
  • The effect of personality strength on job performance and,
  • How to tweak your existing personality assessment tools to measure personality strength in an assessment context

This post is based on over 30 papers on personality, task performance, personnel selection, and personality assessment, pulled from Personality Psychology and Work- and Organizational Psychology. 

personality at the workplace

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The modern view on personality at the workplace

The old view – Traditionally, personality described a person’s average behavioral tendencies (i.e. traits) on five dimensions (i.e the Big Five, or OCEAN):

  • Openness to Experience (open to feelings, new ideas and behaviors), 
  • Conscientiousness (organized, diligent, and abide to rules), 
  • Extraversion (sociable, outgoing, and enthusiastic), 
  • Agreeableness (trusting, altruistic, and compliant), and 
  • Neuroticism (self-conscious, anxious, and impulsive). 

To measure each personality dimension, we would typically give people a personality questionnaire that contained questions measuring each trait in general or on average. To measure extraversion, for example, someone might rate from 1 (not at all) to 7 (very much) whether “I am the life of the party” and “I gain energy from being around people.”

Thus, if someone scored high on extraversion on average, it was presumed that they would behave similarly within a future work context. 

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The modern view – But is it realistic to predict work behavior based on a candidate’s average behavioral tendency?

Let’s consider the extraversion example again. Everyone knows that, despite someone’s general tendency to be sociable, outgoing and enthusiastic, they will probably be more outgoing when going to a party with friends than when going to a public library. Thus, despite being the result of exactly the same behavioral tendency, the expression of our sociable behaviors can vary tremendously between situations.

In the scientific literature, the extent to which a situation impacts behavior is called situational strength.

Although originally neglected, recent research has shown that people differ largely in the extent to which their behaviors, feelings and cognitions are stable or variable across situations. Simply put, this means that some people remain very consistent in the way they think, behave and feel in different situations, while others think, behave and feel very differently depending on the situation.

These differences are also called “personality strength.” People with strong personalities behave similarly regardless of the situation, whereas people with weaker personalities tend to be more influenced by the situation.

situations affect personality

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Implications of “personality strength” in the workplace

First and foremost, looking at personality strength will allow you to better capture a candidate’s personality, as it will give you an indication of how consistent a candidate will behave across different (work)situations.

Work can be seen as a collection of tasks, each presenting a new situation. Every change in work pressure (e.g. deadlines, or lack thereof) represents a new situation in terms of conscientiousness.

Every time you have to approach a stakeholder (e.g. client, customer, colleague) represents a new situation in terms of extraversion. Having information on a candidate’s behavioural consistency (i.e. personality strength) will therefore tremendously help you in predicting work behavior. 

Moreover, recently there have also been indications that the extent to which a person varies across personality traits may be predictive for certain work-outcomes. 

For instance, a study on core self-evaluations — a personality trait that encompasses a person’s subconscious, fundamental evaluations about themselves, their own abilities and their own control — found that momentary shifts in core self-evaluations are linked to momentary shifts in work-performance.

strong vs weak personality

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How should you measure personality strength?

So now that we know that it is beneficial to consider personality strength, how can you measure it in your organization?

The gold standard for the measurement of personality strength is through “experience sampling”, where people are repeatedly asked to report how they feel, think and behave (e.g., three times a day for 15 days). This is of course a procedure that’s untenable for most organizations. So we will discuss three options that might work for you: 

  1. Self-reported personality questionnaires,
  2. Situational judgement tests, and 
  3. Assessment Center Exercises.

We will provide tips that will allow you to create assessments (or tweak your existing personality assessments) to start measuring personality strength.

measuring personality strength

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Self-reported personality questionnaires

In self-reported personality questionnaires, the candidate is typically asked to report how they behave, feel, and think in general, across a wide range of situations. By using a frequency-based response format, it is possible to obtain personality strength information.

In a frequency-based response format, candidates are not asked to indicate to what extent each item in the questionnaire describes them or applies to them in general. Instead they indicate how often they behave in different ways across a set period of time. This allows you to capture both the average level and the variability of a candidate’s behavioral traits.


How do you implement this in your self-report personality assessment?

The process for implementing self-report assessments is fairly straight-forward. Candidates simply answer your questions, then you calculate their scores. The trick is to make sure your existing questions address personality strength (i.e., personality variability). We’ll walk you through a simple way to do that, including exactly how to calculate your scores.  

The math is simple, but you may find that using Excel or another program to automate your calculations makes it easier for you.

Create the questionnaire

If you aren’t already using a personality scale to measure candidate personality, choose one. We recommend well-validated scales like the Big Five Inventory (or you can also use our cognition calculator – which is the implementation of the big five above as a mini free web-app) and the Ten Item Personality Inventory). Let’s say that you are using the NEO-PI-3 to measure a candidate’s Big Five traits, and that you are interested in a candidate’s level of conscientiousness.

First make a list of the items that you would normally use, for instance,

  • I’m known for my common sense. 
  • I sometimes act thoughtlessly. 
  • I have good judgment. 

Next, put the items in a 3-answer format, such as in the diagram below. Use the following instruction: 

To what extent do the following statements describe my behavior in the last six months? Please rate what percentage of the time you felt that each statement is Very inaccurate, Neither accurate nor inaccurate, or Very accurate. Ensure your percentages add up to a total of 100% for each statement.

If needed you can tweak the question a little bit to better fit the format (this is not necessarily needed, but it could enhance the readability of the item).  

Here is an example with a couple of items to keep it more readable:

personality strength assessment sample results

Calculate the traditional average trait score and personality strength

Average Trait Score. Multiply the “Very Inaccurate” percent by .01, the “Neither Accurate nor Inaccurate” score by .03, and the “Very Accurate” score by .05.  

This means that each item has a minimum score of 1 (100 * .01) and a maximum of 5 (100 * .05). 

For instance, for the first item in the example above, you would calculate: 20 * .01 + 70 * .03 + 10 * .05 = 2.8. This means that the respondent scores a 2.8 out of 5 on this item.

Pro tip: Do take note that items that would normally be reversed (i.e. behaviors that are opposite to the trait), are also reversed in this format. This means that Very Inaccurate will be multiplied by .5 and Very Accurate by .01. If you may feel that this is too difficult, you can also reword the reversed questions. For instance, you can turn “I’m not very ambitious” into “I am very ambitious”. Just be sure that all the questions measure in the same direction.

The average trait score is measured by adding up all the item scores and dividing it by the number of items.

Strength Score. Personality strength is measured by calculating the average standard deviation of the items. The way you do this is by calculating the standard deviation for each item — we suggest you use excel to calculate the standard deviation or otherwise you can use an online calculator like this one. Then add up all the standard deviations  and divide by the number of items.

Interpret your scores

Our new personality trait score will now lie between 1 and 5, with 1 being very low and 5 being very high. The personality strength score will lie between 0 and 47, with 0 meaning that personality strength is at its weakest


This means that the higher the value for personality strength, the more accurate our personality assessment will be at predicting how that candidate behaves across different job situations. 

In other words, a candidate with an average score of 4 out of 5 and a personality strength of 40 will act more in line with the desired trait than a candidate with an average score of 4 and a personality strength of 20.  

Thus, the candidate with higher personality strength may be the better choice (in terms of personality fit). That candidate behaves more consistently across situations, and may therefore have a higher chance to enact the desired behavior during work situations.

The score of the candidate with the lower personality strength, on the other hand, may not be an accurate representation for the candidate’s future work behavior, as the candidate’s behavior is more susceptible towards situational cues. This makes it more difficult to predict how they will behave in a particular work situation.

calculating your personality strength

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Situational Judgement Tests

A second way to measure personality strength is through the use of Situational Judgement Tests (SJTs). SJTs are tests that consist of a series of (hypothetical) work-related situations in which the candidate is asked how he/she would behave. 

SJTs may be challenging to develop but it is well worth the investment as you can tailor them to all the details that make you work-environment.

Typically, the situation-descriptions or SJT items contain information regarding the subject, location, novelty and participants of the situation. Although not specifically developed for assessing personality, researchers recently have started designing construct-driven SJTs that specifically target personality traits.

How do you implement SJTs in your personality assessment?

Consider what personality traits and subtraits you value. The takeaway message from this test is when you prepare situations, you also rate to what extent the answers relate to a certain desired personality or its sub-facets. 

Consider which personality traits and sub-facets are important to your position. A list of the sub-facets is available here. These sub-facets make up the overall personality trait and often are highly correlated, but a person could be high in one sub-facet and low in another sub-facet.  You may want to discuss with management or get feedback from successful people in the position to determine which sub-facets are most important.

Conscientiousness, for example, has six facets: 

  1. Competence 
  2. Order
  3. Dutifulness
  4. Achievement Striving
  5. Self-Discipline
  6. Deliberation

You might value some of these sub-facets more than others, or you may want to ensure a candidate is high (or low) on all of them. 

Create SJTs that pit traits against traits. Here is where you may need to get creative and design some questions that measure the traits you are interested in. Consider having a brainstorm session with colleagues to determine which traits are important, what types of common work situations these traits come up, and how you could craft a creative SJT.

For example, if you value both Dutifullness and Achievement Striving, you could create an example like the following one which measures both sub-facets.

Your boss has assigned you to give a presentation on last month’s sales report. At the moment, however, you also have an impending deadline for a project that you promised a co-worker that you would work on. What would you do?

  1. As you have promised your co-worker to complete the project, you will make sure that the project is finished before you start working on the presentation, causing you to divide your resources on both tasks (higher level of “dutifulness” (+) & lower “aim for achievement” (-)).
  2. You tell your co-worker that you cannot reach the deadline because you have to commit yourself fully to working on the sales report (lower level of “dutifulness” (-) & higher “aim for achievement” (+)).
  3. You ask another co-worker to finish the project and start working on the report (lower level of “dutifulness”(-)).
  4. You work overtime in order to make sure that both assignments get the attention they deserve (higher level ”dutifulness”(+) & higher “aim for achievement”(+))

Here you can see that each answer has a different level of conscientious behavior linked to it. Answers A has one negative and one positive, adding up to a score of 0. B also has a score of 0, C has a score of -1, and D a score of 2.  

By creating multiple situations you can again calculate the standard deviation between the scores which will give you, apart from valuable information on situational behavior, also an extra indication on the candidate’s personality strength.

SJT and personality strength

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Assessment Center Exercises

The third possibility to measure personality strength is through the use of Assessment Center Exercises (ACs). Assessment centers typically include a variety of exercises such as role-plays, group discussions, oral presentations and fact-finding exercises. 

Similar to SJTs, they resemble actual job-related tasks which enable an assessor to make predictions about a candidate’s proficiency in job-related areas. In contrast to the self-report questionnaires and SJTs, ACs are observer-rated and allow for observations of actual behavior rather than self-reported behavioral intentions. 

Due to time and cost restraints, ACs are typically only based on a small number of exercises (with an average of seven exercises). Such a setup does not yield enough observations per applicant to reliably assess within-person variability.

Multiple speed assessment procedures may address this limitation. In this procedure, candidates go through a large number of short AC exercises. For example, instead of organizing a traditional 30-minute role-play task, one might organize 5 shorter 6-minute role-plays. Such an adaption to the AC procedure allows obtaining a larger sample of observations per candidate across independent tasks, allowing a reliable indication of one’s personality strength.


How do you implement this in your personality assessment?

Consider which personality traits and skills you value. You may want to measure a candidate’s level of extraversion, and you are also interested in the candidate’s presentation skills.

Develop a series of small tasks to assess personality and skills. The takeaway message from this procedure is to divide big tasks that measure a skill up into multiple smaller tasks that also incorporate your personality trait.

For example, if you want to measure extraversion and presentation skills, you could ask candidates to give several 4-5 min presentations under different conditions.

  • The first presentation may be for only 1 person.
  • The second can be for a group of people.
  • The third presentation will have to be an interactive presentation.
  • The fourth presentation will be co-presented with another person.
  • The fifth presentation will have people coming in and out during preparation.

The same steps can be applied to any exercise (e.g. group discussion, role play), and with any personality trait. Just break the task into smaller tasks that look at the different facets of the personality traits that are of interest.


Recap on Personality strength: the hidden ingredient to better personality assessments

Although personality plays an important role at the workplace, the way it is currently measured may not be sufficient enough to answer the question it seeks to answer. 

By taking personality strength into the equation, we can more accurately capture a candidate’s personality, and therefore better predict work-related behavior.

While methods are still being developed, three ways you can incorporate into your personality assessment practices are:

  • Use a Frequency-based response format 
  • Add personality elements into real world situational judgment examples
  • Incorporate personality measures into Assessment Center Exercises by dividing up big assignments into multiple smaller assignments that each introduce a specific element of the personality trait that you are interested in.

Following these tips will give you a good head start into more accurately assessing your potential employee’s personality. Still it is advisable to, from time to time, check up on the progress of the aforementioned methods and see whether they can be implemented in your company.

For more information on how to retain the employees you’ve selected please take a look at our post on Psychological contract breach.