There are several important factors to consider when evaluating aptitude and personality together. Aptitude testing measures specific skills required to perform a job, personality predicts how a person will go about that job day after day.

General cognitive aptitude, which commonly includes measures of verbal, numerical and abstract reasoning, is significantly related to job performance. The more complex the job demands, the more basic mental aptitude plays a part in successful job performance.

However, aptitude testing alone is not enough to assure that an employee candidate is a good fit and will perform successfully at a job. Hiring managers should test personality, in addition to aptitude, to get a full and accurate picture how an employee will perform.

Personality tests measure different aspects of future job performance – so using mental ability tests and personality assessments can significantly increase the predictive power of an assessment battery.

There are a few more important points to be aware of when combining cognitive aptitude testing with pre-employment personality assessments.

Aptitude Assesses Maximal Performance; Personality Predicts Typical Performance

Aptitude tests only measure how well a candidate can potentially perform job-related tasks, not how well that person will actually perform them on a day to day basis. Personality tests help identify if a candidate possesses traits that would impact factors as quality, timeliness and efficiency. The classic example of relying solely on aptitude testing to make hiring decisions is the “smart, but undependable or sloppy worker.” Making a hiring decision based on a worker’s aptitude results alone may result in problems with their work – oftentimes not long after hire. Personality testing gives employers deeper insights about how employees will perform over the long term, helping to identify potential high performers.

Abilities Change; Personalities are Stable

Abilities and aptitudes can change as employees age, as experiences and skills evolve or as an employer’s needs change. These developments might challenge a manager to help employees grow with the company. An accurate understanding of required skills helps employers match workers with jobs and manage change in that regard.

Personalities, however, are enduring over years and even decades. The hard-working employee who works hard and shows up on time every day is likely to continue to do so, even as skill and knowledge requirements for a job change, or as their abilities change over a period of years.

A Complementary Conclusion: Use Both for Best Results

Selecting the right test for the job is an important activity. Many employers make a mistake of ‘one size fits all’ – this does not work with either aptitude or psychometric tests.

When used as pre-hire assessment tools, aptitude and personality tests should complement one another. They should never be used in isolation, but should be used along with other hiring measures to provide evidence and support to make a solid hiring decision.