The Number One Predictor for Success in the STEM Professions

February 28, 2019


The recruitment and staff selection process is about prediction – you are trying to predict how well a particular candidate will perform, technically and behaviourally, in the advertised position.  To make predictions you need information and data.

So what data is the best data to collect?  What data is the best predictor for success in the STEM professions of science, technology, engineering and mathematics?

General Intelligence

Firstly, in broad terms, general intelligence, or more commonly known as IQ, is the single most effective predictor of job success.  The importance of general intelligence in job performance is related to complexity.  Occupations differ considerably in the complexity of their demands, and as that complexity rises, higher general intelligence levels become a bigger asset and lower levels a bigger handicap.  In more complex jobs, a person’s level of intelligence predicts success better than any other single factor, including education and job experience.

General intelligence has been shown to be the most consistent predictor of performance across a variety of jobs because it indicates a candidate’s ability to learn and thus reflects how quickly a person can be trained.

Other Factors

Of course, there are other factors that contribute to a person’s chances of success, including aspects of their personality, motivation, socio-economic status, and luck, but there is also ample evidence that general intelligence is the single most valid predictor of productive work behaviours and training performance.  Conversely, high-IQ individuals may lack the resolve, character or good fortune to capitalise on their intellectual capabilities.

In relation to recruitment decisions and gathering data, IQ is easy to measure and is without a doubt the most objective piece of data you will get about a candidate.  All other data, including reputable personality profiles, have degrees of subjectivity.

Spatial Awareness

In relation to the STEM professions there is something else to consider beyond general intelligence and that is spatial awareness.  Spatial awareness, defined by a capacity for mentally generating, rotating, and transforming visual images, has been shown to be a better predictor of success in the STEM professions than general intelligence and plays a critical role in engineering and scientific disciplines.  Tests for spatial ability might include matching objects that are seen from different perspectives, determining which cross section will result when an object is cut in certain ways, or estimating water levels on tilted bottles of various shapes.

The Study of Mathematically Precocious Youth (SMPY), a talent search initiated at Johns Hopkins University in the early 1970s, identified gifted adolescents using quantitative, verbal and spatial tests.  These participants have been followed for over 25 years and those who earned bachelors, Master’s, and doctoral degrees in science and engineering fields had especially strong spatial abilities compared to the rest of the sample.

The findings, which are consistent with those of other recent studies, suggest that spatial awareness plays a major part in creativity and technical innovation and those who score high in tests of spatial ability often excel in the STEM professions.

Thus, if you are recruiting employees in the STEM professions I would recommend you incorporate tests of general intelligence and spatial awareness.  Whilst all your candidates will have the appropriate university qualification, there will nevertheless be differences between them and gauging that difference is difficult, if not impossible, from a transcript of their scores.  University results are not standardised across different institutions and a distinction at one university may be a credit at another.  A degree is a good starting point, however, if your business is aiming for excellence, selecting staff who score well on intelligence and spatial awareness tests is a good starting place.  Even marginal differences in rates of return will yield big gains – or losses – over time.  Hence, even small differences in general intelligence among people can exert large, cumulative influences across the life of a business.