[justin_vanw]

"A great deal of time has been wasted in the effort of measuring the heritability of traits in the false expectation that somehow the genetic nature of psychological phenomena would be revealed."

There is a strong cultural bias among much of the research community to go out of their way to deny any genetic factors in intelligence. Perhaps this is well intentioned, but it is absurd.

I have come across very few squirrels that have mastered fire, or could be taught calculus, or even addition. I doubt that this is cultural or due to the squirrels upbringing, diet, social status, or how many books the squirrel has available to it, or the quality of it's teachers, or pathogens. Clearly then, it is possible for genetics to completely dominate other factors in determining intelligence. In the animal kingdom at large heredity/genetics account for basically all of the variation in intelligence.

The unanswered question is whether there is enough genetic diversity across the human species to cause intelligence to be significantly hereditable. The fear among scientists that try to keep the lid on this question is that the answer might be yes, and worse that such variations will correlate with geographic or national groupings. This would put a very nasty perceived scientific stamp of approval on racism (even though this would be unjustified), and could over time lead to discrimination and 'scientific racism'.

Anyway, in the end science will uncover the truth here, and in the meantime it is probably very prudent to not make any potentially inflammatory statements and to be very cautious about any studies that could fuel hate. I just find it absurd that whenever this kind of question comes up people start denying that there is any hereditary component of intelligence, and that IQ is completely meaningless, etc.

[uncomfytruths]

You're not alone. I've always wondered, how come different dog breeds have different behavior and intelligence levels. Yet certain breeds are much smarter than others and capable of greater learning capacity. Any kind of comparison, even scientific, between human races would be seen as racist and thrown out immediately. It conjures up all sorts of negative emotions. Hitler, Nazis, Eugenics, Master Races, Holocausts.

I think deep down inside we are slaves to our genetics and many people know so and have significant evidence for it but are keeping quiet. And I don't blame them. The repercussions of telling the human race "Your success, happiness, intelligence, health, and entire life is limited by your genetics." would be horrific. Half the world would be on anti-depression medications if you told them that and proved it. No one wants to be told who they are before they're given a chance to discover themselves on their own. Also, genetics are not the end all of success. Just because someone doesn't have the genes that make them more likely to be successful doesn't mean they'll never be successful. There are other ways around. Aggression, luck, money, hard work, etc....

For instance, Ashkenazi Jews have the highest intelligence and very poor Spatial intelligence according to research. After them come north east Asians. Jews are disproportionately successful in numerous fields. 25% of Nobel prize winners are jewish and this is increasing. All of the major Hollywood studios were started by jews and are currently dominated by jews. The NYT's Joel Stein could only find 5 non-jewish executives in all of Hollywood. Most of the top writers are also jewish. Banking and finance is dominated by them as well. So is the fashion industry: Marc Jacobs, Ralph Lauren, Marc Echo, Calvin Klein, Estée Lauder, Kenneth Cole, and others are jewish. Levi's jeans as well. 2 of the internet's biggest companies, Google and Facebook were started by jews Larry Page, Sergey Brin, Mark Zuckerberg. People's refusal to acknowledge that genetics has anything to do with intelligence is exactly what has sprouted numerous conspiracy theories to try to explain why jews are so well achieved.

Also, look at men vs women. How many wars have women started compared to men? Nearly every war, genocide, and conflict has been caused entirely by men. Why is it that we never see the female versions of Hitler, Gangis Kahn, Napoleon, Stalin, etc... Because evolution has created extremely violent men (not all of us of course). Evolution wise, we're disposable. Women are not. The human race can easily be replenished with 99 women and 1 man. But not with 99 men and 1 women. And so women live much more "slow but steady" lifestyles while men are more likely to live "risky" lifestyles. Rewards are proportionate to risk. So men reap the rewards when it comes to inventions, companies, religions, nation building, etc...

[Eliezer]

> Evolution wise, we're disposable. Women are not. The human race can easily be replenished with 99 women and 1 man. But not with 99 men and 1 women

This is not how evolution works. It runs on which genes outreproduce which other genes within a species, and cares nothing for "the good of the species" or "the survival of the species". If men are more violent, it was because individually more violent males outreproduced less violent males - not because "males are disposable". (Even this is still a simplification relative to inclusive genetic fitness, but it's definitely not because "males are disposable!")

http://wiki.lesswrong.com/wiki/Group_selection

[uncomfytruths]

That's exactly how evolution works. Because there is an element of human choice as to which genes go on. We are a part of evolution. We choose what goes on. And we have chosen through war and death that violent men go on, and peaceful men die off. We have chosen that men are disposable, we build our armies with men, we sacrifice the men, and keep the women at home because they are the creators of humanity and men the destroyers and conquerers. Primative but it's reality.

All throughout history, wars are fought almost exclusively by men. Men killing men is alright by nature, because back since tribal times, the testosterone induced violent winner got the women and reproduced. Thus passing on his genes. The violent genes outreproduced the peaceful ones. Look at nature all around us. The violent dominate the peaceful, the aggressive dominate the passive, the intelligent dominate the dumb. The animals at the top of any foodchain are more violent, aggressive, and/or intelligent than the others beneath it.

I have a feeling we're both talking about the same thing just from a different viewpoint.

[obfuscate]

And it's a shame that postulating genetic group selection is so attractive, since ISTM that this is a very plausible case of group selection of memes about male and female tasks.

[Claudus]

That example doesn't really apply if tribes continually split and the more violent tribes continually kill off the less violent tribes.

[malbertife]

"Also, look at men vs women. How many wars have women started compared to men? Nearly every war, genocide, and conflict has been caused entirely by men. Why is it that we never see the female versions of Hitler, Gangis Kahn, Napoleon, Stalin, etc... Because evolution has created extremely violent men (not all of us of course)."

One thing is to say that a war is unlikely to be started by a woman (your historical observation); another thing is to say that a woman is unlikely to start a war (your claim). That's because, historically, the people in a position to start a war have mostly been men.

If W means that a given leader (i.e., someone who could have started a war if he or she wanted to) was a woman and S means that the leader started a war, by Bayes' theorem the probability of the leader having started a war, given that she was a woman, is

P(S|W) = P(W|S) P(S) / P(W)

Likewise for men (if ~ means negation):

P(S|~W) = P(~W|S) P(S) / P(~W)

You observed that P(W|S) is much smaller than P(~W|S); but to compare P(S|W) and P(S|~W) you also need to take into account how much smaller P(W) is than P(~W).

[nhoj]

"Half the world would be on anti-depression medications if you told them that and proved it."

So at least their unhappiness isn't limited by their genes?

[nacker]

The horrific repercussions of loudly proclaiming the obvious are completely nullified by the near universal preference for comfortable illusions. Don't worry, be happy :)

[ralfn]

I love your example! Way out of my depth here, but i do have a question:

The squirrel obviously has a genetic trait that causes it to have a small brain. We can tell its iq just by looking at it, without considering its DNA. Would the same logic apply, when there is no visual/physical trait present?

Can one brain cell be dumber than another? Could they be wired in a less optimal way?

Genetics likely explain the difference between a retard and a functioning human, but csn they also explain the difference between an iq of 100 and an iq of 105?

When people have this debate about intelligence, the inevitable political argument is that maybe, we as a society could invest more in ourselves, our children and our neighbours children.

The relevant question, perhaps, should be: how much impact could "nurture" have? Is somebody with an iq of 120 physically limited to become smarter? Or is that person already in the range, where the genes were all good?

I dont think anybody doubts that a retarded person has a genetic disadvantage. But does the same apply to an average human being?

And if that limit exist, is it a personal limit, or one you share with most other humans on this planet?

[DividesByZero]

The squirrel example is absolutely absurd - there are clear physiological, morphological differences between human beings and squirrels that influence whether or not squirrels even have the capacity to master fire, or whatever other silly comparison you choose. Furthermore, I think you will find that environmental factors plainly influence the behavior of animal populations (squirrels, chimpanzees, birds - any kingdom, genus or species you choose) far more than any particular genetic variation among them - animals of the same species without abundant resources behave quite differently from animals of the same species in an environment of abundance (one need only look at any pest species - animal or plant - to see that this is true).

There does not exist much variation across 'societies' of animals within the same species - one tribe of baboons is much like another tribe - but there exist vast gaps between societies of human beings, so far as these gaps influence the environment of individuals among populations, and entire populations as a whole.

There is no physiological model for human intelligence, and since only physiological traits are inheritable (though psychological traits may be derived from morphological differences) there is no model for genetic influence on intelligence. Since there is no model, you can only blindly test a black-box hypothesis - and the results from those tests appear to support the conclusion that there does not exist any inheritable, physiological difference that would influence intelligence, controlling for societal factors.

[hazov]

I don't think it's absurd, I only think initially that it was wishful thinking, now I see that it was only a poor example to a good idea that he explained later.

Yes intelligence has to do with heritability, there was initially an animal with had cognition (a word I much prefer instead of intelligence) this animal actually had descendants some of which are humans, we initially inherited this intelligence from him but also from other ancestors that developed this cognition latter as well.

You provided that we do not have a physiological model for intelligence, and I believe we will not have one for some decades at least if I'm to be optimist. That's a real large problem, another one is to relate this to genetics and environmental development, these would be a hard problem as far as I was told by some friends that are biologists.

[DividesByZero]

My point regarding not having a model was to bring the genetics/environment statistics onto the same footing - the black box statistical evidence does not accept that genetics is a factor in measures of intelligence, but does accept that environmental factors such as income and health are.

[DividesByZero]

I would also add, that the political agenda is not from those advancing the idea that environment influences human development, but from those that contend it is genetics.

Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor - why would you support development for poor populations of people if it was found that they simply don't have the same development potential? You would simply screen for the 'genius' gene and push the rest of society toward a supporting role.

In the case of the environmental view, you must now implement policies that raise the living conditions for the majority of people in society - better and more schools, better and more social programs, better opportunity - that's expensive, and there's not much money to be made.

[justin_vanw]

"Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor..."

You have somehow completely missed and then parroted back my entire point. If it turns out that genetics plays a key role in intelligence, and therefore intelligence is hereditary, all sorts of nazi-like policies could be theoretically be falsely argued for using that as evidence. Seeing this obvious conclusion, some in the scientific community have become crusaders, trying to squash any debate or research into this topic, making it taboo.

Being taboo, or having very negative or even awful potential consequences doesn't make something true or untrue. The universe doesn't care that the consequences of some fact are moral or immoral.

I am not saying the truth is one way or the other. I am pointing out the willingness on the part of some scientists to refuse to allow investigation because of the potential consequences of knowledge of the truth.

[hazov]

Some? Who? I think that's an unfair accusation.

What I see sometimes in these discussions is people throwing the "hot potato" in the hands of their detractors, people that believe in the difference between groups throw the potato in the hands of the disbelievers and accuse them of being obtuse for trying not to advance an "obvious truth".

The other side just answer by accusing the others of being "racist".

The fact is the data is poor for a significant statistical analysis and for some reason this research has become heavily politicized, this in academia is a good enough reason for some people just ignore this entire field, but I never saw people trying to prevent this type of paper from being publicized or peer reviewed, last time I searched there's various being published every year.

EDIT: typos

[justin_vanw]

Are you serious?

How can you say "that's an unfair accusation." and then in the next line say "The other side just answer by accusing the others of being "racist"."

I agree that there is no consensus, and no evidence that clearly helps determine the truth here. That is why I said it was an "unanswered question" in GGP.

However, we do have some ability to reason about this. Clearly genetics can play a role in intelligence. We don't know if it does between humans, but we do know that it could. Humans are very abnormally (as successful species go) genetically similar, probably because of various population bottlenecks.

So, it could go either way. It is quite obvious to me that there is a very complex interaction between genetics and environment. Some populations benefit from breast feeding, other populations do not. This is genetic. There are clearly some hereditary differences which have a measurable consequence in brain development. To what extent do these explain that one random person might be an idiot, while another might be a genius? I honestly don't know, but we shouldn't shut down debate.

[hazov]

Yes, I am serious, and I am not disagreeing with your point, which as I wrote about in a comment bellow was clarified in your first response to me in this thread, I actually do agree about your last three paragraphs.

It appears however that you stopped reading my comment when you saw this the second quote that you wrote, here what I wrote before:

"What I see sometimes in these discussions is people throwing the "hot potato" in the hands of their detractors, people that believe in the difference between groups throw the potato in the hands of the disbelievers and accuse them of being obtuse for trying not to advance an "obvious truth"."

This type of accusation is fairly serious in academia it's akin to say that you just invented data to fit an experiment, mind that I do not have a side in all this, I'm interested in this as a statistician, my point was to get you to give some names of the people that "have become crusaders, trying to squash any debate or research into this topic, making it taboo." No one was given and I said that say this about a group of people and not give any name is unfair.

Everyone knows about who get accused of being racist, Linda Gottfredson for example who received grants from the Pioneer Fund, I do not know about others that received grants from this Fund but I can say about Gottfredson, she came to Brazil two years ago and talked to an audience of students in Brazil, some of whom have visible African ancestry and I can attest she's not racist, she does not differentiate people because of their ancestry and do not act different answering questions of asian-brazilians, people with jewish surnames or afro-brazilians, she's honest her research and that's all.

Mind also that I have spent some time in academia and the majority of people I saw really hates politicized research, there's exceptions of course, some social scientists, historians, some legal scholars and economists, but I did not count psychologists in this group. As I said to you I asked some psychologists to provide papers some of them fairly recent.

This was my last comment in this thread it was a good discussion.

[DividesByZero]

Refusal to allow investigation? According to these papers, their has been very extensive investigation with a largely null conclusion. However people continue to push the idea that intelligence is genetic.

[nitrogen]

A null result doesn't prove that intelligence is not genetic, it only says that whatever genetic components there may be have not yet been disentangled from other genetic and environmental influences.

Edit: Also, another HN commenter raised the possibility that the authors of the present study may themselves be biased (https://news.ycombinator.com/item?id=4257220).

[nitrogen]

Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor...

Though I do realize that some people think this way, it strikes me as wholly bizarre. If you can identify a strong genetic component of intelligence, the obvious conclusion to me is to develop genetic therapies to boost the intelligence of the entire population, with the greatest gains to be had among those who would otherwise be on the lower end of the scale.

[Terretta]

> There is no physiological model for human intelligence...

No? I've read several. For example:

"The pronounced convolution of the human cortex may be a morphological substrate that supports some of our species’ most distinctive cognitive abilities. Therefore, individual intelligence within humans might be modulated by the degree of folding in certain cortical regions. We applied advanced methods to analyze cortical convolution at high spatial resolution and correlated those measurements with intelligence quotients. Within a large sample of healthy adult subjects (n = 65), we detected the most prominent correlations in the left medial hemisphere. More specifically, intelligence scores were positively associated with the degree of folding in the temporo-occipital lobe, particularly in the outermost section of the posterior cingulate gyrus (retrosplenial areas). Thus, this region might be an important contributor toward individual intelligence, either via modulating pathways to (pre)frontal regions or by serving as a location for the convergence of information."

http://cercor.oxfordjournals.org/content/18/9/2019.full

And:

When we examined the same regression model excluding ICV, some cortical measurements were associated with IQ frequently in frontal and temporal lobe. It might conclude that human intelligence is significantly correlated with the cortical complexity coming from brain size, rather than cortical shape itself. The combination of various cortical measurements explained 52.57% of IQ. The results showed that they were more useful for prediction of human intelligence than alone.

http://www.iaeng.org/publication/WCECS2011/WCECS2011_pp428-4...

I'm not defending these particular papers. I'm just baffled at the comment that there are "no" physiological models for intelligence.

The following paper appears to directly contradict your assertion that "there does not exist any inheritable, physiological difference that would influence intelligence":

"Variation in gray matter (GM) and white matter (WM) volume of the adult human brain is primarily genetically determined. Moreover, total brain volume is positively correlated with general intelligence, and both share a common genetic origin. However, although genetic effects on morphology of specific GM areas in the brain have been studied, the heritability of focal WM is unknown. Similarly, it is unresolved whether there is a common genetic origin of focal GM and WM structures with intelligence. We explored the genetic influence on focal GM and WM densities in magnetic resonance brain images of 54 monozygotic and 58 dizygotic twin pairs and 34 of their siblings. ... These findings point to a neural network that shares a common genetic origin with human intelligence."

http://www.jneurosci.org/content/26/40/10235.full

[DividesByZero]

I'll concede this point - there exists evidence that some physiological traits may correlate with intelligence. But there does not exist a model of why or how those traits influence intelligence.

[hazov]

I just curious how you can support your point about squirrels, besides you falling prey of the bias of trying to advance an argument with a sole point.

For example, can these squirrels ancestors had better nutrition than the average squirrel, can we know about that just after seeing they mastering fire or wondering if they could learn calculus? I believe this type of question, the relation between nutrition and intelligence, can be answered much easily than searching for genes and looking for some desirable psychological trait in there, this can be easily tested in animals as well in a large couple of generations.

Either way I am not a biologist or even an psychologist so this is my take as a mathematician/statician. Also I'm not so confident science will ever come as close to explaining this completely.

[justin_vanw]

My point is that humans are much more intelligent than squirrels. Is this because of environment? Not at all, it is because we have the genetic programming to develop huge brains. The difference in intelligence between humans and squirrels is determined almost entirely by heredity.

The reason I point this out is that it is very common to see comments about heredity not being a factor in human intelligence. It may well be that heredity does not explain differences in intelligence between two humans, or it may be that heredity almost completely explains any differences in intelligence among humans. Science will eventually figure out the truth of the matter. However, heredity plays a very dominant role in determining intelligence, the only question is whether humans are all so genetically similar with regards to intelligence that environmental factors dominate genetic factors.

EDIT: The way I phrased the first paragraph sets up a false choice. Intelligence differences among humans could be hereditary, environmental, or most likely a complex combination of the two.

[hazov]

In the comments of this post however I saw exactly the same point you're saying in your first paragraph, maybe in other discussion forums people denying this is more common.

[astrodust]

The performance of laboratory mice in mazes varies considerably among tested populations, with some mice clearly being "smarter" than others. It's possible to train a mouse to be smarter, to learn, but the effect is only a few standard deviations from the norm at best, not orders of magnitude smarter.

Remember that genetics is, at best, all about probabilities. Just because your parents are athletic is no guarantee that you're an athlete. There's always a one in four chance that you get the worst possible pairing of genes, after all.

Intelligence is a complicated thing. A child who can remember things easily will be considered very "smart" even if they can't do much with that information, whereas one who's very clever at figuring things out will be considered "stupid" if they aren't able to memorize as well.

IQ is such an arbitrary metric that it hardly deserves scientific consideration. It completely glosses over any unusual talents someone might have.