IQ scores - How far do they predict academic and life success?
Updated: Jan 15, 2022
The first thing to clarify is that IQ, working memory, concentration and crystallized intelligence are all different aspects of cognition. These are some of the building blocks of what we commonly call 'intelligence'. IQ is simply one aspect of this group of faculties that relate to intelligence.
There are other important mental abilities that cannot be tested on IQ tests. Creativity - i.e. associative thinking and divergent thinking - is not tested. Logic as applied to multi-faceted situations - which is most situations - is not tested. Problem solving is not tested. Essentially most forms of intelligence are not related to an IQ test. The IQ test measures speed and acuity of certain types of abstract cognition. As a pure measure of mental ability it's extremely limited. As we move beyond academia, personal qualities such as a personable nature and social confidence are both important predictors of success, but again neither are measured on IQ tests. Finally, work ethic and diligence, perhaps the most important aspects related to both academic and life success are not measured on IQ tests. Essentially, most aspects of generalized intelligence and most other useful traits are not measured on IQ tests.
If IQ is such an overrated metric, why is it still so widely discussed?
The main reason that psychologists, particularly American psychologists, like IQ tests so much is because it's an easy thing to measure. Psychology is a discipline that can measure very little. For a field wishing to be recognised as a hard-science, IQ tests were a boon. This led to them being enormously over-emphasised in importance by psychologists, sociologists and eventually employers.
What do we know about generalised intelligence?
IQ tests are not particularly useful in measuring intelligence. In fact, even the concept of generalised intelligence is not that useful in the real world. Intelligence is largely domain specific and tends to be highly localized - i.e. my ability in languages does not assist me in Physics, much less in driving a car. Even within one domain, such as verbal ability, intelligence is highly localized: my ability in French does not assist me with Portuguese. The notion of 'generalised intelligence' has limited real-world application. One commonly used phrase by some commentators writing about IQ is: 'An IQ test tests your ability to do an IQ test'. In my opinion, this is the most accurate thing an IQ test predicts. It is true that IQ does have some relationship to generalised intelligence and speed of processing, but it's just one of many factors.
The importance of work and application in developing real-world intelligence When you go to your lawyer or doctor, you don't care what IQ he has, you care about whether or not he has the relevant knowledge or training to assist you. This knowledge and training is achieved through discipline and study, not having a high IQ score. Conversely there are many people of high IQ, but lacking other things such as emotional stability, cultural upbringing and work-ethic that are unable to attain the kind of knowledge required for long term success in any field. There are plenty of high IQ men on the streets and prisons unfortunately.
American education versus European and British Education:
The US has always been obsessed with that test, while other cultures are much, much more focused on knowledge. The American SAT for instance is largely an IQ test - completely different to the European baccalaureate or the English A-levels. The European and English qualifications are subject-specific and require months of study, regardless of your native intelligence, a great deal of knowledge is required to succeed in the tests. Being quick enough to score highly in an IQ test simply will not cut it in the Baccalaureate or A-levels.
One significant weakness I see in the American system is the simple lack of higher level knowledge expected. A student can be mentally agile, but without the knowledge they lack reference points. I personally find the UK and European balance between knowledge and critical thinking skills to be a well-rounded approach. Overall, I think the European Baccalaureate gives the best preparation to secondary school students. My experience has been that Chinese, Japanese and South Korean systems focus mainly on knowledge and tend to have less interest in developing critical thinking skills. The US is really the exception globally. I expect that is because Universities want to get any student with even a modicum of potential through the doors. The SAT test is a reasonable tool for identifying students with potential and it can very easily be administered on a vast scale at low cost and high profit by the College Board.
To illustrate the material difference between the systems,The American SAT involves a single three hour exam - which is extremely similar in format to an IQ test. The essay component on the optional SAT English paper that some students take lasts 15 minutes - not exactly much time for American students to demonstrate their writing skills. In fact it's so measly that it's hard to know why they bother. By contrast, to attain the English A-level qualification, students take three or four papers for each A-level with each paper lasts around three hours. On average students sit three or four A-levels. This equates to over thirty hours of written exams. Science and Maths students are required to solve high level problems while humanities students are required to write analytical, discursive essays requiring a high degree of subject specific knowledge. This requires a lot of arduous study, developing a work-ethic in students that will serve them in future years.
Are Higher IQ countries wealthier?
To draw an economic connection to IQ, even generalised intelligence, as the somewhat infamous psychologist Richard Lynne did in his work, The Bell Curve, is an obvious post hoc fallacy. IQs rise as countries become developed, but a populations IQ does not cause economic development. The question we should first ask is what generates wealth and development? It's somewhat complex, but in short, productivity, cooperative geographical features and economic and political models that are amenable to economic progress. At no point does IQ enter the equation. Even having highly trained academics and gifted intellectuals within a population is no guarantee whatsoever of economic success. Russian economists who set prices for each and every product in the Soviet Union were intelligent people and were certainly knowledgeable - yet their work generated numerous shortages, pricing problems that resulted in starvation - even in places such as the Ukraine where the base products were abundant. The Chinese party leaders of the late 50s were some of the most intelligent and studious men in China - the admissions tests to get into the Chinese civil service were notoriously demanding - yet it didn't stop them from enacting policy which resulted in the deaths of millions through starvation. If you have the wrong methodology and the wrong understanding of economics - the wrong policies - wealth will not be the result, regardless of how intelligent the politicians or population are. IQ tends to increase with wealth, as populations become better fed, better educated and more skilled at abstract thinking, but it does not of itself generate prosperity. Empirical examples of this abound.
What about Science - didn't Einstein have a huge IQ?
Again the primary question should be: What generates good science? The answer is essentially a good scientific education. A high IQ would certainly not be a hindrance to attaining this, but it's merely one small factor of many that are relevant. Far more important is scientific knowledge. Beyond that you need all of the background knowledge of the last hundred or so years of Science. That is acquired by work and study - IQ is not particularly relevant. In addition you need to understand and apply the scientific method - theory, empirical testing, review. What leads to this level of education and experience with the empirical method? Simple - work and study. What causes students to work and study? There are a few factors -culture, families, teachers, accountability, incentives, or just a straightforward motivation from the student. If you don't have the scientific knowledge and the scientific method, IQ, and even natural generalised intelligence are irrelevant.
How do cultures become more intelligent?
When you look back into history - intelligence was always developed through advanced cultures spreading and education. The Romans deemed the British and German tribes to be utterly stupid, totally incapable of any kind of thought, civilisation, advanced construction or even farming - and they were right at the time. However, over the centuries, in both geographical locations the cultures built upon the Roman colonial legacy. Eventually, building on the insights of the European enlightenment and rationalist thought Britain and Germany slowly but surely developed into what they would become in the 20th and the 21st centuries. Churchill famously said that we owe London to Rome - and in a very real sense he was correct. Nobody would have thought in early Roman Britain that the country would produce one of the greatest, if not the greatest Physicists to ever live in sir Isaac Newton, nor the most widely-read dramatist on planet earth in William Shakespeare, never mind some of the most distinguished centres of learning in the world in Oxford and Cambridge. British culture developed and the people became more 'intelligent', not because of a different native ability, but through exposure to education.
The country became wealthy for a number of reasons but by and large it was because people who knew how to create wealth were permitted, at times even encouraged to create it. It's no coincidence that the industrial revolution, the most free-market period in Britain's history, lead to growth rates above one percent for the first time in the nation's history and raised the standard of living for Britain and eventually the world for the rest of recorded history. Every country that has ever become wealthy has followed this model, even the likes of China under the CCP and modern India have allowed free-market principles to lift their populations out of poverty. It's not IQ that is the issue, nor is it native intelligence - it is economic models and political approaches that determine wealth creation.
How do minorities improve their educational and economic outcomes?
You see the answer over and over throughout different population groups - it's primarily cultural developments that create wealth and improve education levels. The Irish are a good example - as a population, their native capacity will not have changed much over the years, yet their educational and economic outcomes have improved vastly. In the early 19th century Ireland, the rural Irish peasants were living in a squalor that was described as worse than blacks on plantations in the American deep south. When the Irish first moved to England and America, they were often barred from entering many restaurants and bars, held only physical labour jobs and were known for violence and drink. Over the last two hundred years, Irish culture has steadily changed - now in the UK Irish families are one of the highest earning minorities and enjoy a higher standard of living than native British families. It's the same in the USA and mainland Ireland itself. This happened because over time the culture changed, not the native intelligence which presumably is genetic. IQ scores actually also change as cultures change and place a higher premium on study and abstract thinking. In the US, the statistics on a number of minorities confirm this pattern - the Chinese, Irish, Jews and American blacks have all seen improvements in wealth and education levels over the decades.
To illustrate how important culture and incentives are to developing a strong educational and economic culture, the unfortunate case of the native American population is an example of a culture that has failed to flourish economically and educationally. This is not due to innate ability, but due to a negative cultural pattern. Native American culture has failed to develop for a number of reasons with the result that those living on reservations have the highest levels of alcoholism and addiction, the lowest levels of both IQ and educational achievement and the lowest median income in the US - far worse than blacks or whites. Unfortunately, due to high levels of federal assistance a culture of dependency and hopelessness has taken route and has had highly detrimental effects. Those native American groups whose families did not settle on reservations and essentially integrated into European/American society have the same economic and educational levels as the rest of the US population. What is the difference? It's not genetics. It's not IQ. It's not native intelligence. It's not even material comfort. Different cultures and different values produce different lives with different outcomes.