For 50 years we’ve known that the best predictor of recruitment success is mental ability. In fact, according to the most recent meta-analysis of research on the predictive power of recruitment assessments, mental ability, on it’s own, predicts 42%–45% of the variance in workplace performance (Schmidt, Oh, & Schaffer, 2016).
The following graph shows the overall distribution of the predictive power of various assessments and other hiring criteria.
So, what have we done with this information? Not much. Many of today’s recruitment processes weigh factors like culture fit, 360 results, emotional intelligence, and personality more heavily than evidence of mental ability.
Interesting tidbit: The original emotional intelligence tests were very poor predictors of recruitment success. Interestingly, many of today’s emotional intelligence tests look an awful lot like mental intelligence tests.
The measurement of mental ability, if it occurs, is conducted at the end of the recruitment process. In essence, the thing we most need to know first is left until last.
Why do we measure mental ability last?
Why do we conduct mental ability assessments at the end of the recruitment process? Because they’re expensive. Conventional mental ability assessments cost hundreds of dollars. This makes them one of the most expensive components of the recruitment process, so it simply isn’t financially feasible to employ them earlier when the number of applicants being considered is much larger than it is later in the process.
Why should we measure mental ability first?
The whole point of studying predictive validity is to determine which considerations should take priority when we make decisions. This means that assessments with the greatest predictive power should be used at the beginning of the hiring process as pre-screening tools. The only candidates considered should be those who have the basic mental capacity required in a given role.
Recipe for a rational recruitment process
Step 1: Start with the best predictor—mental ability
The first question a recruiter should be able to answer is, “Does this individual have the mental capacity to perform well in this role.” Once that question has been answered, the logical next step is to refine the candidate pool further with the second-best predictor.
Step 2: Factor in the second-best predictor—Integrity
The second-best predictor of workplace performance, after taking mental ability onto account, is integrity. Integrity tests measure traits like conscientiousness, agreeableness, emotional stability, sincerity, modesty, fairness, and honesty (Marcus, Lee, & Ashton, 2007 & Ones, 1993). They predict the probability of behaviors like fighting, substance abuse, lying, theft, sabotage, anti-social behavior, and excessive absenteeism. They also predict overall workplace performance (Ones, Viswesvaran, & Schmidt, 1993 &Schmidt, Oh, & Schaffer, 2016).
Integrity is a reasonably strong predictor of workplace success in its own right, while also measuring something quite different from mental ability. This is important because if it was simply another way of measuring mental ability, integrity wouldn’t add to overall predictive power, which is what we need a second predictor to do. As noted above, mental ability predicts 42%–45% of the variance in workplace performance. Integrity predicts an additional 11% –13% of the variance (after mental ability has been taken into account). Together, mental ability and integrity predict 60% of the variance in both training performance and overall job performance (Schmidt & Hunter, 1998 & Schmidt, Oh, & Schaffer, 2016). Importantly, these results hold for roles in all layers of an organization (Schmidt, Oh, & Schaffer, 2016).
Steps 3 & 4: Other relevant factors
Schmidt and his colleagues don’t offer a third predictor. As an employer, depending on the role, I’d turn next to resumes/CVs, and background checks (where required), then competency testing, and finally, personal interviews.
What’s the use of a recipe when you can’t afford the ingredients?
The title of this article promises a rational recruitment process. At this point, you would be correct to conclude that I have done no such thing. What’s rational about starting a recruitment process with an assessment that costs hundreds of dollars? The expense would be outrageous!
However, what if…
- it was possible to pre-screen every potential applicant for mental ability and integrity as the first step in your recruitment process?
- a specified number of pre-screened candidates could be delivered before you even asked for a resume?
- the relationship between the demands of the role being filled and the mental ability of pre-screened candidates had also been evaluated to ensure good fit-to-role?
- the mental skills measured with the assessment were core skills for real-world decision-making, communication, and cooperation?
- the mental ability assessment included an assessment of logical coherence?
- the mental ability assessment could be upgraded later with a report designed to be leveraged in onboarding and training?
- you knew that all applicants, successful or not, would receive an assessment report filled with information and tools designed specifically to support their personal development?
And what if none of this would add to the typical cost of recruitment?
Needless to say, you would have to conduct a rigorous examination of any organization that claimed to deliver such a service. At a minimum, you’d want to know more about…
- the organization and its mission,
- the credentials of its leader,
- the validity and reliability of its assessments, and
- the product.
If you’d like to learn more, please use the form below to sign up for our newsletter—or contact us directly.
Metaanalysis is an evolving discipline in which there is disagreement about methods. Since this paper was first published, alternative metaanalytical methods have been proposed that bring the size of the valididty evidence for recruitment assessments into question. (Sackett, Zhang, Berry, & Lievens, F., 2021). We’ll be keeping an eye on this debate.
Marcus, B., Lee, K., & Ashton, M. C. (2007). Personality dimensions explaining relationships between integrity tests and counterproductive behavior: Big five, or one in addition? Personnel Psychology, 60, 1–34.
Ones, D. S., Viswesvaran, C., & Schmidt, F. L. (1993). Comprehensive meta-analysis of integrity test validities: Findings and implications for personnel selection and theories of job performance. Journal of Applied Psychology, 78, 679–703.
Sackett, P. R., Zhang, C., Berry, C. M., & Lievens, F. (2021). Revisiting meta-analytic estimates of validity in personnel selection: Addressing systematic overcorrection for restriction of range. J Appl Psychol. doi:10.1037/apl0000994
Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124(2), 262–274.
Schmidt, F. L., Oh, I.-S., & Shaffer, J. A. (2016). Working paper: The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 100 years of research findings.