By: Keaton Fletcher
Work Science Center Advisory Council Member, Margaret Beier, recently published a commentary for a special issue of the Journal of Intelligence on the nature of mental ability. Research has supported a hierarchical structure of intelligence such that there is one general mental ability, that is related to more specific cognitive abilities. Historically, the prevailing wisdom has been that general mental ability is good enough, and capturing specific cognitive abilities does not add much information in predicting work outcomes we care about. However, for as long as this has been the dominant opinion, there has been dissent, arguing that specific abilities are valuable and should be considered. Beier and colleagues review and comment upon the findings of a set of articles that tackle this debate from both an empirical and a theoretical perspective.
First, Beier and colleagues highlight that there are genuine concerns with using a general mental ability for human resource management systems. Specifically, depending on the legal context, general mental ability may be seen as too broad to be considered job-relevant and may thus open an organization up to legal consequences. Similarly, measures of general mental ability consistently show minority-majority differences, which can result in legally questionable hiring or promotion policies. Further, Beier and colleagues suggest that measures of general mental ability provide very little diagnostic criteria, thereby limiting their utility for things like training and support.
Beier and colleagues then suggest potential avenues of research and practice that can resolve, or at the very least temper, this debate. For example, general mental ability should be used when outcomes are broad or poorly defined, whereas specific abilities should be used when outcomes are narrow, well-defined, and can be clearly mapped on to a specific ability. Measurement of both general and specific abilities needs to be improved and considered, such that multiple, diverse tests of ability should be used and aggregated to ensure that what is being captured is representative of the entire ability, not just idiosyncrasies of the measure. Here, Beier and colleagues provide the example of a verbal reasoning test. If it was made entirely of synonyms-antonym questions, it would miss out one one’s understanding of grammar, sentence formation, and many other relevant aspects to that specific skill. We also need to begin considering the complexities of the relationship between mental ability and outcomes. Specifically, as time progresses (both within a job and across the lifespan), general mental ability may be less important and specific abilities may become more important. Or, there may be non-linear relationships between outcomes and mental abilities, and the nature of these relationships may differ depending on the ability-outcome pair being examined. Lastly, one of the potential reasons Beier and colleagues suggest general mental ability may be viewed as good enough for predicting performance is that typically performance is poorly defined and measured. To maximize the utility of specific abilities, we need to better understand the specific aspects of job performance and improve our methods of measuring them.
If one thing is certain after reading this commentary, it is that the debate over the value of general versus specific mental abilities is alive and well. Researchers and practitioners should, therefore, give a little more thought into how exactly they are viewing (and measuring) cognitive ability. An apt metaphor Beier and colleagues use is a long nail and a big hammer versus a smaller nail and hammer. Certainly long nails and a big hammer will always get the job done, but the smaller nails and hammer can make a better end-product for very specific jobs. It is up to the craftsman to decide what tool best suits the job, just as it is up to the researcher and practitioner to decide which mental ability is most appropriate for their research question/application.