Is general intelligence, supposedly measured by IQ, meant to underlie all intelligence, be the thing that accounts for all intelligence / ability, or does all intelligence account for general intelligence? Who claims the former, that g is more basic, and why do they claim that?

I think the question matters a little, because, if it doesn't, then IQ scores are a product of learning and teaching successes, rather than vice versa -- given that ability in any sphere [mathematics e.g.] is not innate.

  • $\begingroup$ You should read into positive manifold $\endgroup$
    – faustus
    Commented Apr 14, 2020 at 1:32
  • $\begingroup$ how does that answer my question? thanks tho $\endgroup$
    – user7852
    Commented Apr 14, 2020 at 3:45
  • $\begingroup$ This is how I understand things: suppose i tested you on things you could learn: vocab; french; capital cities; numeracy and things you couldn't learn such as verbal reasoning; reaction time; auditory memory; visual reasoning. And in total, there are say, 20 tests. scores on those 20 tests are positive correlated with one another i.e. reaction time can help me predict french. why is htis? Well, what if each of these 20 tests are all measuring the same thing 'g' just like shadow length at noon, murder rate, ice cream consumption measure something much simpler to do with the sun. $\endgroup$
    – faustus
    Commented Apr 14, 2020 at 17:46
  • $\begingroup$ that's quite a weak analogy: we know that the sun exists and shines independent of ice-cream consumption, and ouor sweet tooth is clearly not underlying the weather $\endgroup$
    – user7852
    Commented Apr 14, 2020 at 23:07
  • $\begingroup$ I think more clarity is needed in the question. Can you please edit your question to include what have you read about different intelligences, IQ and the g factor? Can you also explain when you are talking about "all intelligence" are you including intelligences such as emotional, existential/spiritual and moral intelligence? $\endgroup$ Commented Apr 17, 2020 at 6:58

2 Answers 2


This is an interesting question. Before I even attempt a broad answer, I want to note that we do not have professional consensus on the details here. However, I will cite some research that you can maybe check out and see what you think.

Is general intelligence meant to underlie all intelligence?

To answer this, we first have to define what general intelligence is. A good working definition is the following: g denotes the shared variance in a set of intercorrelated cognitive tasks.

So, when you look at people's scores in a number of cognitive tasks such as arithmetic, vocabulary-based tasks, etc, you find that this performance is highly correlated. Using factor-analysis, we can load these performances onto a general intelligence factor.

We are basically claiming that this high degree of correlation is the result of some underlying factor. (Spearman, 1927; Flanagan, 2014).

Now, it's important to note here that we can't directly test for g. We can only test for other cognitive factors that load onto g.

Test scores as a product of learning and not internal ability

So, you suggested that IQ could be a result of teaching success and that's a problem. I think IQ is a result, at least partly, of teaching success. The IQ test isn't designed to differentiate between biological tendencies and learned abilities.

g is also not necessarily purely biological or learned, it's usually seen as an factor that combines these together. In fact, most cutting edge models suggest that both innate ability to learn and ability that is gained in life load onto g. (Flanagan, 2014).

IQ Scores and g

Now, IQ isn't supposed to be a measure of g. It is rather a measure of a more limited kind of intelligence that combines reasoning, working memory, and a couple other cognitive abilities. (McGill et al., 2018)

It's got its uses, though these are limited and we are probably paying too much attention to it at the moment. IQ test scores are highly sensitive to test-taking conditions, internal and external. (motivation (Duckworth et al., 2011), attention, environmental conditions, etc).

So, while there is a credible theory for general intelligence, IQ probably isn't measuring it. It probably loads onto it, so it may reflect some aspect of g, but it's not directly measuring our general intelligence.

Other Theories and Literature

So, as far as I understand it, the idea of a general intelligence is widely accepted in the literature right now. However, there are detractors, famously Gardner (1983) who proposed that there are different types of intelligence that can't be loaded onto the same one.

While there is some support for this (Visser et al., 2006), I find that the evidence is largely unconvincing at the moment. There is evidence to suggest that these "different" intelligences just load onto g, they are second-stratum. MacCann (2014) does this for emotional intelligence and there's others abound for the rest. (The exception is possibly kinaesthetic intelligence? I don't have that much research on this).

(I would be remiss if I didn't mention that Gardner himself suggests that multiple intelligences can't really be tested empirically since they are only exhibited properly in naturalistic settings. I wouldn't want to hold a position on this matter that isn't empirically supported so I can't defend him.)


So, long answer short.

  1. There is (probably) a general intelligence factor
  2. This general intelligence factors includes stuff that was learned and stuff that's biological, so it does include teaching success
  3. IQ tests are not testing for the general intelligence factor, it is testing for a subset of cognitive abilities
  4. In fact, we probably can't test for the general intelligence factor with a single overarching test anyway
  5. I'd recommend looking into CHC intelligence models for a cutting-edge cognitive model of how intelligence works

Is general intelligence meant to underlie all intelligence?

I don't know what you are trying to ask. Are you trying to ask if general intelligence is the basis of all other intelligence? If this is what you are indeed asking, the answer is no. Long ago, scientists thought of g, general intelligence to be a number that encapsulates the sum of all of one's different intellectual abilities. (I know. It sounds vague and doesn't sound very scientific.) I don't think they intended to mean that g was like some precursor to each type of intellectual process and thus, the best indicator of a person's intelligence.

Is g, measured by IQ, the basis of a person's intellectual abilities or does a person's overall intelligence lead to a number, g? Who claims the former and why?

I reworded this person's question because it wasn't very clear as written. I also think the question is almost exactly the same as the first question, except the person also asks who believes in g as the basis of intelligence.

There was once a time that most scientists and other experts in the field of intelligence believed in the concept of g, a number that encapsulates all the intellectual abilities of that person into one simple score.

As it still happens frequently today, in the early 1990's, there was a remarkable discrepancy in what most scientists believed intelligence was and what popular news articles and media such as movies believed. (This is a topic for a different question but it amazes me sometimes the huge difference between what scientists believe and what the public believes. I personally don't think this vast difference just happens by accident. The information conveyed to the public is usually distorted intentionally.)

Anyway, going back. In 1994, scientists in the field of intelligence were shocked by the public's completely backward notions of what intelligence was. The media was apparently butchering what scientists were saying. As a result, some 50 leading scientists and experts in the intelligence community signed a list of statements that was published in the Wall Street Journal, expressing dismay at the media's incorrect depiction of intelligence. This public statement was titled "Mainstream Science on Intelligence". It stated facts that were widely accepted by scientists and experts in the study of intelligence. Some of these statements were:

  • IQ can be measured well and IQ tests are very accurate.
  • There are different types of intelligence tests but there is only one type of intelligence.
  • Intelligence tests are not culturally biased.

Such outrage by the scientific community! What a shock! Why would the media intentionally distort what the real science was?

Well, all these questions became moot because something really ironic occurred. It was determined that most of the claims made by Mainstream Science on Intelligence were wrong! It's ironic but no reputable scientist or expert in intelligence today would ever sign that statement that they had once so confidently signed and published in the Wall Street Journal. Studies made during and after the 1990's, actually disproved most of the statements in Mainstream Science on Intelligence. Scientists did a complete 180-degree turn. The lying media turned out to be right!

What's more ironic is that there are now laypeople who believe in the statements made by Mainstream Science on Intelligence. Not scientists but laypeople who haven't been keeping up with the science. They are accepting the statements made in the Mainstream Science on Intelligence as true. They believe things like IQ is an accurate and precise measure of general intelligence, g. Or, g actually is a great indicator of how smart a person generally is. Funny, no?

Anyway, the original question had asked who claims that general intelligence underlies all intelligence. I don't think anyone believes this. I never heard of anyone who believes that there are some group of genes (aka g) that has an effect on all our intellectual abilities and is the factor that mainly accounts for a person's intelligence. Next question...

I think the question matters a little, because, if it doesn't, then IQ scores are a product of learning and teaching successes, rather than vice versa -- given that ability in any sphere [mathematics e.g.] is not innate.

I didn't understand this question. How did you logically conclude "IQ scores [are] a product of learning and teaching successes" since "IQ scores [are] incorrect representation of intelligence"? It happens to be true but how did you conclude that from anything you said before or after? And, what do you mean by vice-versa? It doesn't make sense.

To set the record straight, there is no such thing as a g that represents the general intelligence of a person. Just because you are good at one thing, it's been determined that you might not be necessarily good at other intellectual pursuits. I strongly believe this to be true. Research has proven it. And, you personally see instances of this in real life.

Let me also state that an IQ test is also a very inaccurate method to measure intelligence, especially at the tail-end of the distribution on the right side. Furthermore, please keep in mind that the scientific field of intelligence is actually still in its infancy. Many basic concepts are still unproven to be true or not. We are still learning about ourselves. Current studies include determining what types of events appear in what part of the brain. It's all so very new.

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    $\begingroup$ Opinion-based answers are discouraged on this science forum. Please provide references for claims made. $\endgroup$
    – Arnon Weinberg
    Commented May 15, 2020 at 1:46
  • $\begingroup$ Arnon, I know what you are saying but I know that you know that is a lot of work. The above answer didn't come from any specific source. It's all from memory - my general knowledge of the field. If the answer was even slightly controversial, I could see the necessity of citations but this answer is just describing the general history of intelligence research over the last few decades. Nobody is disputing anything I said. I could cite Wikipedia but I hate doing that because Wikipedia's facts are actually wrong more than you would expect. $\endgroup$ Commented Jun 9, 2020 at 6:10

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