While there is no perfect device for measuring general intelligence, g, the efficacy of IQ tests in predicting job capability and performance is well established in the research. Linda Gottfredson, one of the leading researchers in the implications of general intelligence, states: (Gottfredson, Linda S. “Why g Matters: The Complexity of Everyday Life.” 1997. Intelligence 24 (1) pp. 79-132.)
Personnel selection research provides much evidence that intelligence (g) is an important predictor of performance in training and on the job, especially in higher level work. … [In fact] g can be said to be the most powerful single predictor of overall job performance … no other single predictor measured to date (specific aptitude, personality, education, experience) seems to have such consistently high predictive validities for job performance.
On page 81 of that research paper, Gottfredson explains:
Research in job analysis and personnel selection refutes the claim that [general intelligence] g is useful only in academic pursuits. Intelligence turns out to be more important in predicting job performance than even personnel psychologists thought just two decades ago. And, very importantly, the research allows strong inferences about its causal importance.
Measures of IQ across large sectors of the population reveal that most of those who are in the professions, such as doctors, lawyers, or professors, have an IQ that is one standard deviation (15 points) or more above average. See: How does IQ Affect everyday life & career opportunities? – Intelligence and IQ
This is one reason why high school students, contemplating their career path, are interested in knowing their IQ. Evidence of intelligence, such as a high SAT score, increases a student’s chances of gaining entry into a top university. Bill Gates had an SAT score of 1590 out of 1600 and that was a contributing factor in his acceptance into Harvard.
However, the most common factor impelling people to compare their intelligence to others is embedded in our quest for self-esteem. Our physical attractiveness, stature, personality and intelligence are all attributes that we use to define who we are. When a psychologist measures your IQ to be 130, your confidence receives a huge boost. You can easily dismiss an adversary’s charge that you’re “stupid,” and you are more comfortable expressing your ideas. However, if your IQ is measured as substantially below average, you feel diminished and may be reluctant to express a thought, lest someone judge you as incapable.
It’s true that no one knows exactly what we mean by intelligence, but as Justice Potter Stewart of the US Supreme Court said in 1964, “Intelligence is like porn, difficult to define, but you know it when you see it.” While high intelligence is something that most people might wish to include in their self-image, there is also a potential downside to a high IQ. (see: How are Highly Intelligent People Different? – Intelligence and IQ)
