What are intelligence and IQ
Intelligence vs IQ
First, let’s go over some basic definitions so that we have a shared understanding of certain concepts.
Intelligence can be defined as a property of the mind that encompasses many interrelated abilities such as the capacities to reason, to plan, to solve problems, to think abstractly, to comprehend ideas, to use language, and to learn new things.
It is important to note that intelligence is not about how much knowledge or expertise a person has; rather, it is about how fast a person is able to acquire knowledge and expertise as well as how well a person is able to perform new kinds of tasks.
The IQ (intelligence quotient) is a measurement of intelligence. IQ presumes that there are differences in intelligence among the people of a population. It expresses, with one numeric score, how intelligent a person is in relation to the rest of the population.
Is the concept of intelligence worthwhile? How about IQ tests?
As you might have guessed, there is no full scientific consensus on this issue – although we all know that scientists disagree about numerous issues!
What problems do some experts point out? Many contend that intelligence does not relate to cognitive abilities and therefore criticize IQ tests for not measuring intelligence.
This criticism is not completely unfounded. It is true that intelligence is not clearly defined, nor is it easily measured. By contrast, other human dimensions (height, weight, muscular strength) are self-defining and can be measured objectively.
However, we can make certain indisputable statements about IQ and intelligence:
- A general cognitive ability exists, and human beings differ in how much of it they possess.
- All standardised tests of academic aptitude measure this cognitive ability to some degree, but IQ tests, which were designed expressly for that purpose, measure it the most accurately.
- IQ scores match well with what people mean when they use the word “intelligent”.
- Properly designed and administered IQ tests are not demonstrably biased against social, economic, ethnic, or racial groups.
IQ predicts various forms of success
Criticism of IQ tests can be countered by the successful use of IQ as a predictor of success in various domains.
Although IQ is not a perfect predictor of academic or work success, even critics recognize that there is a strong correlation between IQ and many forms of success. This means that a higher IQ is generally associated with higher achievements. What kind of achievements do we mean here?
IQ → academic success
The IQ test was originally designed as a predictor of school children’s academic success. Only later, in the 20th century, was its use extended to the workplace and other contexts.
While it is true that there are many diverse factors at play, IQ has repeatedly been shown to have a high correlation with academic success.
IQ → professional success
IQ can partially predict success at work. Measuring job candidates’ IQ and considering IQ in the recruitment decision is a useful tool. However, the use of IQ tests in the work setting is even more controversial than using them in the academic setting.
Fewer than 50% of employers worldwide use IQ tests as a means of evaluating job candidates, although there are significant differences between countries:
55% → China and Spain
30% → India and France
3% → U.S and Germany
Scientific research suggests that while an IQ test is not a perfect predictor of the future success of a job applicant, and while many other factors are relevant to work success, IQ should indeed be considered.
This is because the candidate’s IQ has a high correlation with future success at work. Recently, researchers compared the effectiveness of various methods of selecting employees: IQ tests, unstructured interviews, personality tests, and biographical questionnaires. The result was clear: IQ is the single best predictor of work success.
According to Schmidt and Hunter, “for hiring employees without previous experience in the job, the most valid predictor of future performance is intelligence.” IQ test scores predict performance ratings in all occupations. The effect is the strongest for military training and high-complexity jobs but lower for low-complexity jobs and, surprisingly to some, leadership roles.
That said, for highly qualified intellectual activities (research, management) low IQ scores are more likely to be a barrier to adequate performance, whereas for physical professions, athletic strength (manual strength, speed, stamina, coordination) is more likely to influence performance.
We can also find support for IQ’s usefulness in Justin Menkes’ article published in the Harvard Business Review titled “Hiring for Executive Intelligence”.
Menkes states: “Despite the very real shortcomings, IQ tests are still a better predictor of managerial success than any other assessment tool. The business world’s reluctance to use intelligence testing of any kind has robbed companies of a powerful tool for evaluating candidates for employment or promotion.”
IQ → wealth
As IQ correlates with success at work, it also does with income and wealth. In essence, the higher your IQ, the more likely you are to have a higher income, accumulate more wealth, and attain a greater social status.
Self-made millionaires’ average IQ is estimated to be around 115. Meanwhile, self-made billionaires’ average IQ is estimated to be around 120.
IQ → life outcomes
IQ has also been found to correlate with various life outcomes, although it remains uncertain whether their relationship with IQ is direct or rather caused by high-IQ individuals on average disposing of more wealth.
For instance, higher-IQ people are less likely to die in traffic accidents. In Sweden, higher IQ was found to correlate with decreased risk of mortality in adult men and therefore higher longevity.
The table above shows some astonishing facts about the relation of IQ to various life experiences:
- A person with a low IQ is 6 times more likely to be unemployed than a person with a high IQ.
- A person with a low IQ is almost 3 times more likely to divorce within 5 years after marriage than a person with a high IQ.
- A person with a low IQ is 10 times more likely to go to jail than a person with a high IQ.
- A person with a low IQ is 15 times more likely to live in poverty than a person with a high IQ.