Does IQ predict job performance? This is the verdict

Whether it’s bragging on an internet forum or a haughty note on your resume, those with high IQs tend to have interesting ways of sharing that information with others. But even if a high IQ indicates performing well on a series of tests that measure problem-solving, literacy or math, studies give conflicting evidence as to whether or not a higher IQ might — or might not — take someone further in life.

A human being’s intelligence quotient is a difficult thing to define, and even more difficult to measure.

Mensa International, the famed high-IQ society accepting those only in the 98th percentile, defines IQ as “a type of standard score that indicates how far above, or how far below, his/her peer group an individual stands in mental ability.” Psychology Today adds that IQ tests are known to measure “problem-solving abilities, spatial manipulation, and language acquisition.”

Generally, Mensa says, the average IQ is 100, and contrary to popular belief about the inequality of these measurements, “this is obtained by applying the same test to huge numbers of people from all socio-economic strata of society, and taking the average.” These tests include the Stanford-Benet, the WASC, and even standardized tests like the GRE can determine IQ.

It might seem like an IQ is a fixed notion, an edge you receive at birth due to genetic or hereditary factors, but that’s not the case. In 1963, researcher Raymond Cattell put forth the notion that intelligence is either crystallized, which relies on prior learning and education, or fluid, meaning that the knowledge doesn’t come in facts, but is rather the ability to create inferences and draw points together. Over time, one’s crystallized intelligence is supposed to increase, while one’s fluid intelligence declines as the right cerebellum atrophies.

As to what an IQ can be used to measure, a study on IQ and job performance was done in 2015 by the Applied Developmental Science Journal states that an IQ “has utilitarian value because it is a reasonably good predictor of grades at school, performance at work, and many other aspects of success in life.”

As long as an IQ test is considered valid, and not just a Buzzfeed quiz or a clickbait article, it’s long been considered to reflect the mental potential of individuals.

As for how IQ directly correlates to job performance, it’s an ever-evolving field. “Hundreds of studies prior to the 1970s,” says the Applied Developmental Science Journal, “reported low and/or inconsistent correlations between IQ and job performance.”

This was due in part to the continued frenzy around race and IQ, fueled by the eugenics craze. Some might be familiar with Arthur Jensen’s famously controversial article, in the Harvard Educational Review, “How Much Can We Boost IQ and Scholastic Achievement?“, or the New York Times’ 1973 “Resolution Against Racism” after a flood of race and intelligence-related literature, from The Atlantic to full books.

Once the fad of race-related intelligence studies had largely been debunked as a pseudoscience in the late 1980s, with studies as recently as 2006 disproving this myth, the lens of IQ predicting job performance shifted to a more generalized perspective. Some studies focused on academics, some on time-based mediators, and some on individual differences, but they all generally state the same thing: smart people generally perform better at work because, well, they’re smarter.

In fact, the 2004 Journal of Personality and Social Psychology reports that IQ predicts not only performance but the level of occupation obtained over the course of one’s career.

Inc notes that in this very study, “researchers reviewed dozens of studies and found that smarter people generally perform better at work;” this is determined to ultimately be “because smart people learn new skills more quickly.”

However, while places like the Harvard Business Review might state that IQ “is the single best predictor of ability,” and consequently of job performance, sometimes that’s not the case. Inc also reports that “social skills, drive, and personality traits such as conscientiousness” are deemed to matter tremendously to employers, even if an employee comes off as bright, well-read or quick-thinking.

It’s even been claimed in the 2013 Industrial and Organizational Psychology journal that with the new trend of hiring for personality rather than brains, “companies currently place a much greater emphasis on personality traits than on IQ.”

That being said, it’s currently not known what kind of intelligence indicates one’s job performance in the workplace, and if crystallized intelligence or fluid intelligence plays a role in one’s success. For an airline pilot whose memory requires a great deal of procedure, buttons to push and levers to pull, higher crystallized intelligence might indicate further career growth. But someone hired for a spunky personality, more social skills or higher self-motivation might require more fluid intelligence to further their careers.

Finally, circling back to the Applied Developmental Science Journal’s 2015 study, we’re told to be wary of attributing one facet of an individual’s whole personhood to job performance.

We find that though correlations between IQ and job performance “have many strengths, theoretically,” they can be “compromised in these cases by the often uncertain quality” of many early studies. Ultimately, they state that “great caution needs to be exercised in using job performance as a basis for the validity of IQ tests and associated concepts.”