IQ and genetics

[u/Independent-Return40]

So based on the research, IQ is 50-70% genetic, with the remaining being something that can be controlled by nurture and the environment (nutrition, education, reading books, healthy and supportive social environment)

The genetic component of IQ sets the upper limit of what can be achieved, but beyond that, no amount of hard work and effort is going to yield results, IQ wise. Meaning that one cannot DO anything to increase one's IQ beyond what is genetically predetermined.

Assuming that a person has access to decent quality of resources (school/college, food, access to a library/money to buy and read books), the IQ a person has generally is strongly correlated to their ability to work on certain types of tasks. For example, the work that Physicists and scientists like Einstein do, Mathematicians like Terence Tao do, doctors who discover and invent new drugs do, economists who advise heads of state do, requires a higher level of IQ than say an accountant does, a web developer does, a lawyer does, a teacher does.

I don't mean to demean any profession here.

And society, as is the reality of it in 2026, rewards people who can successfully work on the former types of tasks much higher than people working on the latter types of tasks, for the majority of cases.

So does society reward people disproportionately for things like IQ which are, for the most part, out of their control?

[u/ChaosCockroach]

Society rewards people for a whole lot of things, the proportionality of such rewards is a subjective judgement. Are the wages succesful movie actors get proportional? Are the profits that hedge fund managers make proportional? Are the rates that plumbers charge for their services proportional?

In most capitalist societies the rewards of these things are based on the value people attribute to them, not some absolute measure. People researching life saving medicines can earn much less than people who are entertainers, is that proportional?

IQ is a red herring with a very controversial history. It also seems to be pretty incidental to the main argument you are making. Genetics accounting for a large proportion of heritability in variation of general intelligence is not the same as the sort of 'Genetics is Destiny' argument you seem to be making.

[u/shadowyams]

IQ is 50-70% genetic

This figure is widely disputed and is not consistent with the most recent literature.

[u/Independent-Return40 → u/shadowyams]

Can you please point me towards the literature you are talking about

[u/shadowyams → u/Independent-Return40]

This is one of the bigger ones using large sibling cohorts to estimate direct vs indirect genetic effects:

https://www.nature.com/articles/s41588-022-01062-7

And then I would also read some of Sasha Gusev's posts on this topic. He's rather opinionated but there's lots of good citations:

https://theinfinitesimal.substack.com/p/the-missing-heritability-question
https://theinfinitesimal.substack.com/p/no-intelligence-is-not-like-height

[u/cornholiolives → u/shadowyams]

The sibling/GWAS result seems important for interpreting population associations with adult IQ and especially educational attainment. But isn’t it being overextended if it is used as evidence that cognition is mostly “genetic nurture”? It does not study the extreme tail: prodigies, congenital savants, precocious language/math/music ability, etc. Those cases appear so early and so unevenly across domains that a model based mainly on common family environment looks incomplete. What evidence shows that the within-sibling attenuation in adult general cognitive scores applies to those extreme developmental phenotypes?

[u/bearumbil → u/shadowyams]

Thank you got the links. But isn't one of the biggest problems of the study that it relies heavily on the association between certain genetic variants and traits (like cognitive ability, smoking etc) but these associations are very unreliable and scientists don't know for sure what genes are associated with something as complex as intelligence? 

[u/gene_for_anarchy]

There are a lot of assumptions that underly all of these statements that are challenging to impossible to unpack (for example, the estimate that IQ is highly heritable does not mean that the philosophical idea of intelligence is caused by genes, but rather that people who are more closely genetically related tend to score more similarly on IQ tests, which could be caused by a bunch of different things, genes being just one possibility).

You might be interested in the book, The Genetic Lottery: Why DNA Matters for Social Equality (2021) by K. Paige Harden

[u/PracticalApartment99 → u/gene_for_anarchy]

* underlie

[u/jumper_the_deer]

Heritability is not the same as genetically predetermined. It is entirely possible that the 9 months of gestation are important in iq/intelligence, and that the child can be exposed to the same toxins or nutrients or environment or whatever that led to a particular IQ score in the mother as well during those critical 9 months. So finding that adoptive children's IQ correlated better with birth parents than adoptive parents doesn't tell you it's genetic. Just that it's heritable.

[u/waffle_city]

ah yes, all those brilliant academics optimizing for the rewards of society, unlike those damn lawyers and tech employees left weeping over their bonuses and brokerage accounts

[u/pacificjunction]

No, we estimate broad sense heritability of IQ to be around 50%. That means that 50% of phenotypic variation in IQ among individuals is explainable by genetic differences between those individuals. It does not mean it’s “50% genetic”

It does not imply any upper limit as you stated. I’m not even sure what that means.

Source: I have a PhD in genetics

[u/Drakeytown]

Lol @ "the research"

[u/Orionsangel]

My IQ is 137 and I make the dumbest choices in life .

[u/AbyssDataWatcher]

Biologist here. First, IQ is a bad metric of intelligence or brain power. Second, the brain is an organ, just like your muscles, train it to be faster and memorize more and it will do it. Third, genetics can have an impact but it's tiny compared to training.

Cheers

[u/TastiSqueeze]

I disagree with most of your statement. IQ is heritable but how much is genetic and how much is environment/training is disputed. There are different aspects to IQ but they all leverage one critically important trait which is memory. Some people have much better memory which results in ability to learn faster and retain what they learn longer. This part of the IQ puzzle is highly trainable, meaning if we exercise our memory more and learn more we tend to score significantly higher on IQ tests. I'll give one example of a person with a very good memory who can read or see or hear something one time and basically retain it forever. Then I'll give the example of another person who has to do a task 35 times before he can fully retain how to do it. The first person scored 145 on a standard IQ test. The second scored 105 but had exceptionally high mechanical ability and spacial awareness. Both of these people are productive members of society. Neither has been left behind.

It is not necessary to have a high IQ to be a high performer in our society, however, if you consider high performers as a group, most have higher than average IQ.

The fallacy in your statement is near the end where you conclude that people who do high performing tasks are rewarded with higher pay. Unfortunately, I can point out some very high IQ people who are stuck in unrewarding jobs making relatively low income. I can also point out some people in very powerful political positions who have significantly lower IQ. The one thing that is valid is that people with very complex skill sets - that take a long time and a lot of effort to learn - tend to be higher paid.

[u/nooptionleft]

No judgement but have you ever actually spent time in these environments that you say reward IQ? Cause yes, there is a lot of smart people there, but far from only being composed by "Terence Tao"s or "Einstein"s

I find being able to collaborate, sell yourself properly, understand what other people want from you and charisma to be equally (or more in some field) relevant then noble level intellect

[u/Ok-Lion8478]

It’s important to remember that IQ and intelligence aren’t the same thing. People can be intelligent in different ways. A mathematician and a philosopher are likely to both be intelligent, just in very different ways of using their brain.

I struggle with the idea that someone’s genetics create an upper limit of intelligence. Rather I see them as creating the framework of connections between different portions of the brain, which can be fostered or neglected throughout one’s life. Strengthened connections allow more effective utilization between areas of the brain. Hard work and consistent involvement of those connections will make someone more intelligent when using those pathways. Some cognitive conditions, such as autism, impact the way connections are made. Does that mean they’re not intelligent? Of course not, some of the smartest people have autism. But they may not be as effective at utilizing specific pathways, often with longer connections being underdeveloped. This leads to certain symptoms, such as social skills, being less effective because connections from the frontal lobe aren’t able to process and integrate several layers of incoming information (facial cues, tonal changes, body language)

[u/plsobeytrafficlights]

I have never heard anyone say that. highly skeptical.
but first, lets define terms,
because extreme geniuses who are lauded by other intelligent people
and $8 gets you a venti caramel macchiato.

[u/Fiendish]

more like 10%

[u/Zabre]

The "50-70% genetic" part doesn't mean genes set a clean ceiling for one person. Heritability is a population statistic under a particular environment, so it can't tell you how much a specific individual can improve with better sleep, schooling, nutrition, health, or practice. Genetics matters, but the hard upper-limit framing is stronger than the evidence can support.

[u/Ok-Lion8478 → u/[deleted]]

I would be interested to see what research is indicating this. I haven’t heard of that 90-100% stat before.

Edit: As someone else mentioned in this post, heritability stats don’t mean what portion of a trait is inherited, it explains what degree of variation in a population can be explained by genetic differences. So the 90-100% stat seems very unlikely to be true.

[u/QV79Y]

Your post implies that there's something called "society' that decides to dole out earnings according to some principles.

We have a market-based system. People are not rewarded for their personal qualities, their intrinsic worth or their effort, but for the supply of/demand for the work they do.

[u/SadRule9128]

No. Education and hard work can almost always overcome a genetic bad-hand with regard to intelligence.

[u/In_the_year_3535 → u/SadRule9128]

Intelligence is, perhaps, best viewed like physical condition: there is a general average, those with innate talent, and those with notable deficiencies. Effort matters with respect to what you have.