Are family, marriage, pair bonding a certainty or are they a combination of preference and a necessity of paternal inheritance? Matrilinial societies have been studied where marriage is not a norm and care of children is a collective responsibility.

In a study of an Australian indigenous society, children were found to have a lot of autonomy in their actions. They may wake up with a different group of people to those present when they fell asleep, follow their own schedule and join in the activities ongoing at that time. This makes school, with a focus on discipline and regimentation an alienating experience.

Evolutionarily speaking, did such collective responsibility, where a child’s survival is no longer tied to their parents’, allow a longer childhood and greater capacity for learning in humans?

Is individual parental responsibility then a convenience found in wealthier (or at least city building) societies, perhaps providing a larger labour force, a necessity of urban life, or a consequence of economic competition?

Alienation from school is hardly unheard of for young children in western society, could discipline and strict routine be an unnatural imposition of economics on the human condition and counterproductive to learning and development?

During the 20th centuary, colonial europeans believed themselves superior to the populations they conquered. Ibn Khaldun however, in seeking cause for the collapse of empires through a detailed study of their history, thought them inferior to their userpers due to a breakdown in social cooperation enabled by the very economic and military advances responsible for their earlier success.

I ask these kind of questions not to assert any claim to truth, but rather where I see blind spots in the discussion of what is natural. People tend to substitute what ought (according to morality and expectations) or their own observations (what appears to be) for enquiry into what is.

I find such blindness goes well beyond theology or philosophy, the stories we tell ourselves about the world influence how we interpret scientific results. It was until recently popular to assume a competitive dynamic equilibrium was the reason ecosystems existed. However the iterative prisoner’s dilemma showed a model where incidental cooperation between unrelated entities would be favoured and selected for over competition, despite the strategy appearing disadvantageous to the individual when assessed as an isolated logical problem.

Perhaps the simplest natural example is pollination by insects. Insects that take nectar without pollinating dont gain from the promotion of their food source, while plants that attract insects without providing pollen don’t gain from promoting the survival of those insects.

If one is looking for a basis of human morality, promoting cooperation between unrelated individuals might be a hypothetical start to the line of enquiry.

These northern Eurasians were thus mentally pre-adapted, despite their simple social organization, for later technological developments, even though such developments were possible only in more southern environments for which these populations were less ecologically adapted.

Failing to explain exactly why such developments were only possible in “more southern environments� and not the Arctic or subarctic is a missing link in this thesis.

Charles Cornwallis and Carlos Botero have suggested in their ‘Cooperation facilitates the colonization of harsh environments’ that hierarchical social organisation, which you point out as absent in these proto-European hunting societies, was difficult or impossible to maintain in the Arctic and subarctic. It is also true that domestication of plants or animals – excluding the highly specialised reindeer – to create agricultural and/or pastoral societies was impossible in high latitudes and also the lowland Western Hemisphere. Indeed, it is precisely because of nonhierarchical social structures (previous point) that animal domestication was and remains impossible in these regions, because herds will never follow a human leader.

If it is not one of these two, what else it is and I would be most grateful for a detailed explanation.

I’m late in the discussion, but the author has to answer my points before he can convince me parents don’t matter (outside their genes) :

1) How could your genes only react to specific environmental factors ? It doesn’t make any sense from a logical standpoint. It’s like saying gravity only works in New York but not in Paris. No, either gravity works for everybody or nobody. It should be the same for environmental influences : either any environmental influence has an effect or envinronment has no influence. Actually, everything react to everything, that’s why causality means something to physicists…

– The only logical and possible explanation is that the studies are unable to properly measure shared environmental influences or don’t look at the right things. Usually, they only care about psychological traits while what really matters are life outcomes, not psychological traits, even if they are correlated. For instance (and by caricaturing) if you score really high in agressiviness, you could become either a succesful boxer or an inmate.

– Let’s say you have a high genetic susceptibility to develop mental illnesses under stressful events : how an unstable family could not affect your innate propency to develop a mental illness ? Once again, it doesn’t make sense.

2) If genes and luck are so powerful, then this article doesn’t matter too, because as said the author : Beyond that it’s in the hands of “fateâ€�.

– Or perhaps the author acknowledge that knowledge can make a difference in your life. And i’m certain that many people here would live their life differently if they knew what they know today. If your parents say you genes matters a lot (and i don’t dispute this fact) then it may influence how you choose your furtur partner for instance…

3) My last point is this one : what we can conclude from those studies is that parenting may not make children more similar in their psychological traits. This doesn’t mean parents can’t affect their child’s life in a positive or negative way. Once again, only actual life outcomes matter and twins studies typically don’t measure that. People with similar personalities and IQ can totally have different life outcomes. Good parents may not make their children more similar psychologically, but this doesn’t mean they don’t make their children more similar in how successful they were in their life.

– For instance, by many aspects, Bill Gates is closer to someone like Snoop Dogg (status, money, etc.) than a random engineer who only earns 2000$ by months.

Excuse me if you don’t always clearly understand me because english is not my native language.

This is not quite correct, I’m afraid.

“The violent young male went from hero to zero, his place now taken by the law-abiding man who bettered himself not through plunder but through work and trade. ”

According to James Sharpe in A Fiery and Furious People: A History of Violence in England , the murder rate in England around 1350 was 120 per 100,000 – double that for Honduras today.

One wonders if the Normans had such a pacifying effect as supposed.

Broken link:

which, as of this writing, is reaching critical levels in Spain.

https://www.google.com/hostednews/ap/article/ALeqM5hyJdb-8EEhBjETpyrnKh92lMQU0w?docId=af84f7d4f42d4b8e9b5b90605ce95267)

I agree with your conclusion that the rate of regression is 0.6. However, I don’t agree that shared environment has no effect. Heritability is not inheritance blah blah blah.

Let’s say I live in a favorable environment that raises my IQ. When I have kids, I’ll pass on some of this environment to them—we might go to the same school and live in the same neighborhood for example. Our shared environment prevents regression toward the mean. However, it doesn’t cause any of the variation between us.

If everyone goes to the same school and lives in the same neighbourhood, it would of course cause little variation between them. (After all, they’re the same!) If only a few people go to a great school and live in a great neighborhood and they pass this on to their children, preventing regression to the mean, but causing none of the variation between us.

I can’t find your sources on the percentage of the different contributors to trait variance. However, the additive heritability (narrow-sense heritability) of fluid intelligence and crystallized intelligence are actually 40% and 51% respectively. What raises the rate of regression to the mean to (allegedly) 60% may actually be shared environments.

I have a similar question to @Not Here

What is the basis of adding those three components, namely:

effect of measurement error, the heritability estimate, and the negative gene-environment correlation values?

Indeed, when we consider the effect of measurement error (adding it to the heritability estimate and to the somewhat nonsensical negative gene-environment correlation values), the heritability of political attitudes and social values skyrockets, being upwards of 85% (74%) for views towards pornography in women (men). The heritability of overall political orientation, when accounting for measurement error, teeters on 100%!

I think I am getting a bit confused here, regarding the bolded…

Why would you add Measurement Error to the Additive Genetic value? I thought the reason that it is removed from the original Additive Genetic value itself is because it is an error and being corrected for.

Nothing in the paper itself says to Measurement error to the Additive Genetic value…

Wouldn’t assortative mating show itself in certain college populations such as the creation of traditional Black colleges creating an environment where higher IQ than average students tending to marry within the population and then sending their children to the same colleges create sustained increase in average IQ for the group? That would be a strong argument for certain types of environments supporting increased IQ, since assortative mating can be an environmental factor.

Regression to the means happens due to unassortative mating. Regression to the mean is a statistical phenomenon not a biological one, there is no evidence IQ regresses towards the mean, it happens because highly intelligent and wealthy men marry attractive but less intelligent women, i see it everywhere around me. If mating is 100% assortative there will be NO regression. What happens is very simple, a man is born with a high IQ, his IQ puts him in a high status job, he marries a very attractive woman, with an above average IQ but not as high as his, and his offspring regress back to the mean of he and his wife’s IQ level. I’ll guarantee that since women don’t marry attractive and less intelligent men, that most offspring of very high IQ women don’t regress to the mean.

social mobility is WAY higher than Clark’s estimate. It’s common for high ability men to marry attractive but less intelligent women, resulting in a sharp socioeconomic and IQ decline in the next generation, especially if they’re boys, since boys tend to be closer to their mother in IQ than their father. Women will try to marry into more intelligent families, raising the IQ of their offspring above their own level, whereas men marry into less intelligent families lowing the IQ of their offspring. The idea that assortative mating is greater today is preposterous, during most of history people practiced arranged marriage, to keep intelligence and wealth from diluting back to average. India’s caste system was specifically designed to ensure intelligence and wealth maintained itself over the generations. People today marry people they “love” it doesn’t matter if her father was a truck driver or elite, people marry by education level, which is’t a great proxy for IQ unless it’s STEM.

Jayman,

I still have a question of your article regression to the mean. I accept the breeder equation to be correct if the model underlying it is accepted, but that may not be the case. You answered before, which was kind, I hope you answer still to this one. Let us take a selected population, say by an IQ test we discard
half, all below 100. The accepted half has the mean sigma*sqrt(2/pi), where sigma is the standard deviation. Thus, with mean 100 and sigma=15, the mean is about 12. The variance is Var(1-2/pi),
where Var=sigma*sigma. Clearly, the selection has reduced the variance, while if we measure SD
from the higher part, it will seem to be 15 and there will be twice as many over any level, like 150,
than in the general population. Then the regression to the mean reduces the mean for one generation,
and we get the mean to 110. Hope this reminds you of the US Ashkenazi. Terman has twice as many Ashkenazi over 150 than non-Jewish whites and Lynn estimated the average to be 110, while before it was measured to about 12. Now the question.

The distribution is truncated normal distribution with below 100 cut off. It cannot stay like that. For each pair of parents, the mean of the children is the mean of the parents, but is the distribution of
the children IQ normal with SD=15, or is it more probably so that for very high IQ, or very low IQ,
the distribution is skewed, because if genetic IQ is polygenic characteristics and both parents have
the good or the bad genes, the offspring cannot have too wide a range, there is nothing to cause
high variation. If so, the distribution is skewed, and therefore the average may actually not be the
mean of the average of the parents, but there may be exactly what you tried to deny, regression
to the mean over several generations.

To say is again. Your breeder equation is correct, provided that the model under it is correct. If
at the high and low ends of the distribition, the variance of IQ, or any property, is skewed, because
the property is polygenic and there is nothing to vary if both parents have all good or bad, then there is a push to the center because of this distribution and it is not true that the average of the children is the average of the parents.

hope I made this question clear enough. thanks for your previous answers, think if this is the case with the Ashkenazi.

Thanks for this answer. It is good enough. The simple formula actually is not the “real” formula,
since it does not take everything into account (women are supposed to have a narrower IQ distribution, parents also should have IQ composed of these parts etc.) but let it be. Rushton and Jensen use a
simpler formula, let it be. I guess this field is still too far from having any really correct formulas for anything.

By the way, I read this your article of ivy collage admissions and the endless discussion of Jewish
overrepresentation. Quite a discussion, so I will not continue this discussion any longer. Must be hard being a blogger.

In Rushton,Jensen 30 year of studies Section 9 (in the web) there is a more simple and maybe
better verified version of regression to the mean. Assuming that an individual has IQ equal group mean+x, then full sibling (or parent-child) has IQ close to group mean=x/2. Using this one would
calculate, group mean=100, son IQ 155, thus father IQ is close to 100=55/2, which is quite fine.
Rushton, Jenkins claim the relation is linear and works from IQ 50 to 150, so there is no need to
make the more compilated calculation with A,B,C,D, which probably works less well.

Or let me present the question in a clearer way. Assume fathers/parents IQ is 2SD (130), son has
3.6 SD (about 155). Does it mean that father/parents additive IQ heritage is 142 and non-additive
heritage or environment lowered it to 130? This is because if additive is additive, there should not
be any distribution any more. Genes are inherited. The reasons for distribution are A,B,C,D, not
so that each or them has a distribution. Thus, father additive IQ 130 is inherited as son IQ od about
118. Then comes max 50% other effects, which do not raise son’s IQ to 155. So, father’s real additive
IQ is higher than 130. Is this what you mean?

Or as I suspect, none of these is what you mean, because this is pseudoscience and one cannot make
calculations with these half ready theories. If one does, very soon one can get to contradictions. Maybe
this is what you mean?

Anyway, I read your article and finally did not understand anything of regression to the mean.

I can’t believe you actually answered to a discussion from 2015!!! That’s very good and probably rare. So I have to comment in some way, I guess.

Assume the father (or the average or the parents) has IQ 130 and the son has IQ 155 (I know such a
case), so the son inherited 118 points by additive heritance of IQ and 37 point, that is 67% of his IQ
(about 3.6 SD) from non-additive heritance and nonshared environment. But you say nonshared environment is typically 20-30% and non-additive heritance is 10-20%, together 30-50%, somewhat
smaller than 67%. Is it so that the numbers you give are means and they still have some variance, or
can one count with them as constants and at the end assign some confidence to the result, such as:
in this case the son should have IQ 100+x, where x<=18+0.5x with probability y (y=?). To simplify,
x<=36 with probability y, and consequently x can be 155 with some probability y2. Is this what you
mean?

But there is another error here: in this calculation that follows your example the father has 130 in
additive heritance, since 0.6 of 130 is inherited, but actually the father has 130 as a sum of all his
three IQ components A,B,D (as C=0). So one could calculate as above only in the case of an average
father, where B and D are zero. Is this also as you mean it?

If you do not care to answer, do not do it, who cares anyway. I already was impressed finding an answer to my first comment.

Is there not some inheritance of luck also, that is, the parents of IQ 130 are probably better off than average and give a better environment, so the breeder equation should not only take the genetic inheritance, set here to 0.6, but inverited environment set to something, like 0.2 maybe. If so, the prediction from two parents is better than from four grandparents.

Regression to the mean would indicate high downward and upward mobility, if class structure was this rigid regression to the mean is clearly overstated. According to Stephen Hsu IQ can go from genius level (140) all the way back down to 110 in 3-4 generations. It’s not uncommon at all for upper middle class people to produce offspring who would be better suited to blue collar work. Regression to the mean is a powerful phenomenon and it indicates that one cannot maintain high intelligence over many generations. Stephen Hsu said that it’s common for super high IQ physicists to produce kids who can “only” become doctors, and doctors could also produce kids who could only become electricians.

You use dictatorship to mendaciously refer to a single party state ruled by a single strong man. Non disingenuous twats who bother to read Marx’s words and take him at his word (instead of interpreting their way around it by referring to every philosophy they fear as “pseudo” this or that) will have inevitably arrived at the heart of the matter he actually described in plain language. The dictatorship of the proletariat is a single party state ruled by the proletariat which would comprise all of society at the end of the revolution.

But by all means just home in on the word dictatorship because it sounds scary (see: bad faith reasoning)

Florence isn’t closed and if you actually read that article you wouldn’t be making demented pleas to genetics to account for this effect. It shows flat out that savings explains the largest explainable part of the effect.

The US is a terrible place to become rich if you’re poor. It falls consistently in social mobility every few years. I suppose you could handwave this away by saying its genetic drift but it isnt. From this we can infer the obvious; that it isn’t what you know, or how much you’re able to know, but who you know. Intelligent people often become rich because of the confidence it affords them, not the ability. One of my former employers was in most respects a fucking moron but he was ruthless and single minded as most HBDers/phrenologists are.

If you think single mothers are the victims of their single mother genes, there’s just no way to put this politely. You’re a fucking idiot. My IQ surpasses my mother’s and fathers by a long shot. Maybe I have a rare mutation? Maybe, just maybe the IQ test is worthless and contaminated beyond hope and you rely on it because it offers simple, convenient explanations for a confusing and frightening world that you pretend you can grasp on equal terms but can’t. Genes don’t code for behaviors, but proteins that form tissues which work in a complex, dynamic system which creates an emergent property known as consciousness. Try tying the preference of apple to pecan pie to genes. Try tying a fear of getting water stuck in your ears to genes. You can’t and you’ll always be putting the cart before the horse in any attempt to do that.

All you do is cherry pick studies that seem to be saying what you think they are, deliberately misinterpret them to fit the a priori position that’s comforting to STEM seeking social retards and deriving a harebrained philosophy from that a priori position (everything everyone does is down to genes.)

We know shit all about genes but we know that they turn on and off all the time. We know that identical twins have contrasting personalities which shouldn’t be possible at all if we were clockwork men. We know now that there isn’t a single type of intelligence but there are many types of intelligence, and that a system that measures it by using a single numerical rating value is inherently ridiculous and should be laughed at. Your ego (and subconscious black shame) governs everything you believe, and it does so in concert with genes, not solely and unequivocally derived from the proteins they encode. You should be embarrassed and ashamed, but not because you have black genes, but because you don’t have the will to override them.

Single parenthood is merely the result of bad genetics, hahhaha. Morality police (or lab rats) ahoy
http://www.slate.com/articles/double_x/doublex/2013/01/single_moms_are_better_kids_raised_by_single_mothers_are_sturdier.html

Jayman, Don’t know if you will see this here, or another source.

http://blogs.wsj.com/economics/2016/05/19/the-wealthy-in-florence-today-are-the-same-families-as-600-years-ago/

Basically, if you live in Florence, and your ancestor was wealthy in 1400’s, odds are that you are also. It seems to fit your ‘son becomes the father’ It is worth noting that income mobility is higher in other areas, but this also could be explained by genetics. In the US, where a poor man can become rich and a rich poor more easily than about anywhere else, that dynamic is desired, so those who seek their fortunes migrate to the US and away from areas where they can’t.

Steven Pinker has this to say on epigenetics:

Molecular biologists have appropriated the term “gene” to refer to stretches of DNA that code for a protein. Unfortunately, this sense differs from the one used in population genetics, behavioral genetics, and evolutionary theory, namely any information carrier that is transmissible across generations and has sustained effects on the phenotype. This includes any aspect of DNA that can affect gene expression, and is closer to what is meant by “innate” than genes in the molecular biologists’ narrow sense. The confusion between the two leads to innumerable red herrings in discussions of our makeup, such as the banality that the expression of genes (in the sense of protein-coding stretches of DNA) is regulated by signals from the environment. How else could it be? The alternative is that every cell synthesizes every protein all the time! The epigenetics bubble inflated by the science media is based on a similar confusion.

https://www.edge.org/response-detail/25337

If you haven’t picked that book up yet, I recommend it JayMan. It’s a great read.

Ok, I contacted Peter Frost and also found a link to Greg Cochran and you are correct it seems. That would be enough to explain Aschenazi IQ right there then, wouldn’t it, assuming differential birth and survival rates for the merchant/scholar class and perhaps some out migration on the part of the poorest, least successful members of these endogenous communities (schtetls) in Eastern Europe?

Evo and Proud begs to disagree on 3rd generation resetting of mean:

Regression to the mean is something else. It happens because of genetic change. For instance, a man with above-average IQ will likely marry a woman with above-average IQ. But only part of their above-averageness is genetic. The rest is due to favorable circumstances. Or simply luck. So their children’s IQ will likely be a bit closer to the mean of the overall population. That second generation will in turn marry people with similar IQs. And their children will likewise be closer still to the population mean. Eventually, several generations later, the descendants of that original couple will have a mean IQ that matches the population mean.

I’d like to see more plain english confirmations of Jayman’s position on this important point. If Jayman is right it would be HUGE. But I am dubious.

Regression to the mean happens mainly when some individuals born comparatively more-evolved than its population. They tend to be the first of a novel genetic combinations.

It is not my experience in the least that BanglaDeshis are mild mannered. Those I knew in East London were quite rough. They are physically small but went in gangs and are therefore more than a match for blacks.

Who suggests physicists think they are masters of all sciences?
They have the right to have a go at any scientific issue like everybody else.

Shmigg, concur. Question for you, since you see the threat; Can you see our Hispanic influx one day battling Obama’s Muslim influx for control of the U.S., post-White-European society? Say, 50-80 years hence? Perhaps a new American civil war? It happened in South-Central L.A. Blacks hardly have a place to hang their hats anymore.

Obama’s people are the Syrians, the Muslims. He was happy to use Hispanics to his own ends, but is not the undertow of Africans from Libya, Syria, Iraq and the rest not Obama’s challenge to the Hispanics? My wonder is that Hispanics and Blacks in America are not protesting the Muslim undertow into the United States. Hispanics and Blacks will inherit the United States, yet they utter not one peep about the new competition being introduced.

Thoughts?

There are at least four caveats here.

1) There was self-selection in the case of László Polgár, he needed to be highly intelligent to even conceive of the idea, and to try to raise his children to become great chess players (as opposed to, say, great swimmers or whatever)
2) There was self-selection in the case of the wife, Klára. Many women would have opposed or obstructed his plan.
3) There was self-selection on the level of the story: we only here about the successful one. There might be a few other families who also planned to raise their kids to be geniuses, but didn’t succeed.
4) The three Polgár sisters’ chess skills are nowhere near each other. Judit Polgár (the youngest of the three) was the strongest female player of all time, Zsuzsanna (Susan) Polgár (the oldest of the three) is a Grandmaster, whereas Zsófia (Sofia) Polgár (the middle sister) is only a Woman Grandmaster. The point is not to belittle the latter title (I’d be proud of my daughter if she achieved that), but simply that they are not nearly all on the same level, in spite of having received the same education and upbringing.

Great post. Yes, you could have added the fact it’s a sampling effect.

Link in previous comment: http://chronicle.com/article/Bringing-Up-Genius/234061

OT: Bringing Up Genius

Before Laszlo Polgár conceived his children, before he even met his wife, he knew he was going to raise geniuses. He’d started to write a book about it. He saw it moves ahead.

By their first meeting, a dinner and walk around Budapest in 1965, Laszlo told Klara, his future bride, how his kids’ education would go. He had studied the lives of geniuses and divined a pattern: an adult singularly focused on the child’s success. He’d raise the kids outside school, with intense devotion to a subject, though he wasn’t sure what. “Every healthy child,” as he liked to say, “is a potential genius.” Genetics and talent would be no obstacle. And he’d do it with great love.

H/T: Arts & Letters Daily

Interesting how they are a Hungarian Jewish family.
https://en.wikipedia.org/wiki/Susan_Polgar#Personal_life

I don’t think you really give a fair treatment of regression to the mean. A good theoretical model of regression to the mean is that given continuous unimodal symmetric independent random variables A, X, X’ with X, X’ identically distributed and m = A + X > E[A + X] then E[A + X’| A+ X = m] if m < E[A+X]) . In other words if we have some underlying ability (true IQ etc.. etc..) A and some noisy measurement of A then the result of that measurement is an overestimate of how extreme A is.

If we think of genetic outcomes as the result of some heritable component A and non-heritable component X (the effect of enviornment and lucky combinations of genes that aren't practically heritable) then this tells us that if mates are selected to share the same heritable component A then we should expect their offspring to be less smart. This DOES continue indefinitely in the following sense. If your ancestors IQs were m1, m2 … mk and the average m of m1…mk is greater than E[A + X] then your expected IQ conditional on your ancestors having IQs m1…mk is less than m. In other words part of the reason your ancestors are smarter than average is probably luck so you probably won't be as smart.

This isn't incompatible with any kind of selection pressure. Just because each generation is likely to be more average than their ancestors doesn't mean they become arbitrarily average. The size of the regression to the mean effect reduces as you condition on more trials.

In other words if your parents are geniuses you have good reason to think a great deal of that is probably luck and you will be much less smart than they are. If both your parents and grandparents are geniuses then the family intelligence is probably partly luck so you will be somewhat less smart. If the last 10 generations of your family have an average IQ of 121 that is probably only slightly due to luck so you should expect your IQ to be only slightly less than 121.

Of course using this model in genetic can be a bit tricky since deciding what A is to measure and what does and doesn't go into the heritable component isn't obvious (nor a perfect model).

I don’t see how any of the assumptions of this model hold up.

First, there is the idea that shared environment explains roughly nothing in terms of IQ variance. Many researchers who make this claim refer back to McGue’s 1993 review. However, Kaplan 2012 showed that this review was deeply flawed, especially with respect to its calculation of C. Specifically, Kaplan notes that McGue’s data most straightforwardly implied a C of -.06, an impossibility. Rather than finding this data to be problematic, McGue simply subtracted .06 from E to arrive at 0.00 for C. Kaplan was also able to show that the problem lied with elderly samples: if you restrict McGue’s sample to only include twins below the age of 60 you get a mean C value of .17. This is consistent with more contemporary studies, such as Hartworth et al. 2011 and Kendler et al. 2015, both of which showed significant effects for shared environment. Hartworth et al. is especially note worth because its sample size was dramatically larger than McGue’s was. Over all, contemporary intelligence research does not support the idea that C is zero for adults. (And, of course, it never supported this idea for children. This is especially note worth since regression to the mean studies often involve children or adolescents.)

Secondly, the assumption that E is random is counter intuitive and, so far as I know, not backed up by any significant evidence. There is no obvious reason to suppose that parents are totally unable to transmit non-shared environmental abnormalities that they experience to their children.

Lastly, D is certainly not random. If your parents posses some genetic feature which has a non additive impact on a trait you will be more likely than the general population to also posses that genetic feature. The fact that it isn’t assured doesn’t change the fact that the probability will be greater than average.

thanks ive been wondering about that. even without accounting for proles probably having more children one third is not a trifle contribution ide imagine they also are keeping the blue blood from turning green.

This whole discussion is shot through with misunderstanding of H2. The concept has no applicability to individuals. A group can have a mean weight, while the individuals of it have a weight. A group can have a mean H2 for some trait, but no individual has an H2.

So if H2 for some desirable trait T is .8 it is no more likely that a individual will inherit T than if the H2 is .3.

First you need define specifically what is “mean”. Where begin where finish the mean.
In my opinion and specially for this iq-context, mean is unlikely to be a single number but a spectrum where majority of people fit. Just look for bell curve that illustrates this post.

I want to second this. The reason to prefer this wording is that it doesn’t suggest that the regression is always complete or will be at some point in later generations. “regression to the mean” makes these misunderstandings more common I think.

Jayman, please remove my previous post. If I understand correctly, the problem I had with twins making environment more similar would result in inflation of C estimation, right?

Damn, I waited too long with edit. Sorry Jayman for the additional post.

With twin studies, for example I wonder what would be the impact of more similarity of MZ than DZ twins. MZ twins will have similar interests and will create more similar environments than DZ twins.

Well, I re-read “All human behaviour is heritable”, and C!=0 for:

#. Asocial behaviour (.09 for adults)
#. Conservatism (yes in females above 20 years old)
#. RWA (0-0.16 in adults)
#. Religiousness (0.2-0.4)
#. Psychological interests (0.08-0.12)

I’d say that this still opens a possibility that for some psychological traits C is non zero.

And I still don’t get twin studies ðŸ™� (why you can estimate C from difference between monozygotic and dizygotic twins. I would understand that if you would have monozygotic and dizygotic twins sharing the same environment – i.e. from the same family, but I do not get how the formulas can work if they do not share the environment, even if averaged over large number of different twins and environments ðŸ™� )

I read your article you linked to, and I don’t see what it has to do with my point. It says that if the additive effects are negligible, in practice we can expect that the interactive effects will be negligible as well (though they don’t have to be), because it would be surprising for the mechanism to exactly balance out additively.

I agree, but that doesn’t apply to my point. If there’s a (currently) rare treatment, then because it’s rare, we would expect the overall shared-environment effect to be negligible, even if the treatment had a strong effect.

Re your reply that a change in means over time “means nothing for behavioral genetic studies”: Well, it’s a type of environmental effect that’s totally invisible to the kind of studies your talking about. That says only that the studies themselves are limited, nothing wrong with that. But it also says that many people (including you, but you’re in good company) interpret the findings of the studies wrongly, by drawing conclusions that go far beyond what the data imply. By the way, there are plenty of people who have pointed this out, I’m not claiming any originality here.

Look, measure after measure (see my above comment) finds that C = 0. This is an empirical matter. And the case is closed.

You didn’t express this degree of certainty when responding to Aaron Gross: “Except that for the shared environment, the fact of the matter is we have reason to believe that zero means zero. See: Apples, Oranges, and Lesbians: The Nurture Assumption Just Will Not Die.”

I’ll read your piece before commenting on interactions; here I only seek clarification as to which position expresses your real degree of confidence. I doubt the degree of confidence you expressed in reply to me can be justified, when an informed and objective commenter like Ron Unz has concluded that there must be some undiscovered error behind the c = 0 conclusion. [Why isn’t c = 0 for height – to interject a question of my own.]

On the other hand, if the heritability studies only “give us reason to believe,” other evidence might give us greater reason to believe otherwise. Speaking now only hypothetically.

Pointing out that the issue is “empirical” is … I don’t know .. a bit demagogic. Of course it’s empirical. What else might it be? Logical? Metaphysical? But heritability studies aren’t the only relevant empirical evidence, good scientists don’t ignore evidence that hasn’t been scientifically verified.

Ok, about supposed nazi experiment, is very very likely to be a BS. 😉

But the rest is right, is not??

True but wouldn’t proles contribute at least as many high IQ university students as the elites?
{ Say elites produce 100% high IQ students and all go to university, and proles produce 1 out of 100 of the prole population with a plus 130 IQ and they all go to university, and prole pop is is 100x the elite population of over 130 IQ} I chose >130 IQ because i think that’s the 1%, adjust if im off.
So now we have an equal number of stabilized high IQ elite children and regression prone prole High IQ children at university together. Even without any further mating proles have doubled the number of the nations high IQ quotient. Further assuming the elites can and want to still mate only with their class, and the prole university kids all marry out of the prole elites group to average prole mates. The proles will continue to add as many cognitive elites every year as the elites do.
BUT what I think will/ does actually happen is elites have a much harder time identifying each other at university and very little interest in perpetuating a class division and so in reality they are mating as often with high IQ proles as high IQ elites.
Now if you agree with me so far the question I am not informed enough to answer is how much regression are the elites picking up and how much are the proles losing in these mixed mating’s what is the net gain or loss in the next generation as measure against a pure bred model.
I would think if it is even a wash its still quite a gain because the elite pool is growing but it could be there’s a increase in breadth and a loss of height to be considered, but I suspect the diminishing odds of of super high IQs in the long run benefit more from larger pools than more concentrated input.

No, no please I want to see this great shitting refutation of epigenetics.

…Please.

I’d prefer that you would rather write a detailed explanation on methodology behind twin studies. For example, after reading both Hanscombe, Trzaskowski et al article (about heritability in UK twins) and wikipedia articles on twin studies, I feel dumber than before.

I mean I understand that you prefer not to answer to question you think are stupid, or your first reaction to someone writing “I feel dumber than before” may be “maybe it’s because you are dumb”, but still quite a lot of readers would gain a lot from simple (simplified?) explanation of the twin studies models.

I think we also have look for regression to the mean as individual proportion of favorable biological variables that produce a set of intelligence phenotypes spectrum. Everyone inherited a certain favorable proportion if intelligence(s) is(are) polygenic.

Would be interesting look for families with only sons and with only girls. Are there significant trends between couples of different sex ratio among their children?

I don’t know if it’s correct to say but we will go try…

Regression to the mean metaphorically speaking is like you threw a little quantity of red paint into a bucket with blue paint. The red color will appear occasionally, if you mix the paint.

The more red ink in the bucket you play, the greater will be your quantitative presence.

Another metaphor. Duplication of a cell. Do you have a population ” with ” average IQ of 90. So the smartest begin to interbreed, we think they decided to found a divergent worship where they secretly only those who score 3 digits in IQ can participate.

Initially, there will be many cases of regression to the mean, by logic, because you have many individuals with unfavorable mutational load for greater intelligence who are getting married to each other. Then, over time, going with progressive segregation those with (contextually, i mean intelligence) favorable mutational load and over time, it will occur to fixation / prevalence of these favorable genes.

First we have the emergence of a genetic insularity within a larger gene pool. Then over time, you have the separation of this deviant group until the moment they are not as related as before.

Let’s assume that you ‘have’ a iq 130 within a community where the average IQ is 90.

First, you’re likely to marry within this community, especially if the community is inbreeding,

Second, you will have trouble finding a spouse with the same average IQ than you,

Third, it is likely that you will have low genetic load for greater intelligence, especially if you’re a cognitive outlier within your family (one Lisa Simpson), because, high levels of inbreeding tend to depress ” intelligence ” (or type of intelligence that tends to be related to IQ and fluid moral intelligence, if it exists),

Room, you also need to know if the spouse to choose comes from a family with greater intelligence. Generally, families tend to cluster by social class,

Fifth, it is possible to conclude that heredity vary with its age. So, the older you are, the better the chances to pass mutant genes, which may or may not depress intelligence (this should also be investigated more hard). Having children too soon also may cause problems or reduce the biologic potential of its progeny.

I’m very curious about the Nazi experiment in a city in southern Brazil (and Argentina) where, it seems, an hour to the other, began to be born twins in a large percentage. If this was really true or if there were an excessive history of twins in this city.

It seems that there is an inheritance hierarchy, as did the experiment (quasi-unethical, but valid, not to cause suffering to the ” animal ”) with the mouse, it just got smarter.

Maybe you can make a recessive gene or even of polygenic nature, in a dominant gene. Anyway, I’m not a geneticist, just curious.

Please do.

One very easy way to see that it’s not a causal effect or process is to remember that it goes both forwards and backwards in time. For instance, just as our children regress towards the mean compared to us, our parents regress towards the mean compared to us as well. I think that fact can give people a better intuitive understanding of regression toward the mean.

You know, this is an interesting point. If the shared environment has no effect within cohorts (and there’s a whole lot of variation between families), then that greatly narrows down the type of environmental effects that could lead to observed differences between cohorts.

That doesn’t seem right. First of all, any new environment will by definition not have affected the variation within the previous cohort, although maybe that’s what you meant by “greatly narrows.”

But it’s not just new effects that can cause a big change between cohorts. For instance, suppose hypothetically that playing a certain obscure work by Mozart to infants greatly increases their IQs. If only a minuscule number of parents currently play that music, then the shared environmental effect will be negligible. But if everyone started playing that music, then there might be a huge difference between cohorts.

This goes back to a statistical or logical fallacy that lots of people make, including famous people like Judith Rich Harris. All variances – those explained by genes, shared environment, etc. – are averages. It’s a fallacy to say, “The shared environment effect is negligible, therefore none of the shared environments today have a strong effect on the trait.” But that’s exactly what some people say or imply.

Finally, your statement seems wrong for a much more general reason. While for a given cohort the mean is fixed, between cohorts the mean is changing. You have no way of knowing a priori what effects a change in the mean will have.

Hand waving away a whole new area of scientific study? You do realize that they have done DIRECT experiments that prove transgenerational epigenetics right?

May I ask you to turn your attention to a Hbd matter which is perhaps not an order of magnitude less important than IQ but rarely treated as a normally distributed characteristic?

I refer to the number of hours sleep different individuals need and the approximate inverse number of constructive hours work they can put in each day.

My starting point is countless articles and interviews telling us that we need (as adults) 7.5 or 8 hours sleep for various restorative and other housekeeping functions and that, ever since Thomas Edison became famous for only needing four hours sleep Western civilization has been infected with chronic sleep deficits. Well, maybe, but…..

It seems clear that our hours of sleep allow a great many different functions to occur from recharging some endocrine/hormone supplies or their glandular sources to arranging and consolidating memories to repairing muscle fibre damage and much more.

Presumably these processes are controlled by a large number of genes plus epigenesis and there is no reason to suppose that their identity and efficacy wouldn’t be distributed normally in much the same way as genes for IQ and other mental characteristics. A point which I have not heard raised but which seems prima facie correct is that there would be only a loose connection – if any – between genes for one restorative function and another. Thus there is no reason to suppose that the clever person who was blessed with being able to use his brain effectively for 17 hours a day (and become Chief Justice let us suppose) is necessarily going to be able to keep his cardio-vascular system healthy without another two hours sleep.

My guess is that the healthy adult’s requirement is on average about 7.5 hours and that the SD is about 50 minutes. Have you an opinion on this, even evidence? And do you know of anything bearing on my hypothesis that not all sleep’s functions would be performed equally effectively in the average individual? It could certainly help explain the collapse in health of some people whose brains had achieved great things although it is my experience that the imagination and lateral thinking which I really enjoy tends to fail me when I am forced to push myself without sleep to keep on exerting expertise in some reasonably testing situation in which one can perform satisfactorily because of practice and experience.

I think the point so many miss is that this is for averages for sufficiently large groups. We can all tell anecdotes about friends who are average height but their son is 6’5″ or some such.

Regression to the mean is generally true and true for sufficiently large groups. There are outliers.

So, Joe is the smartest from his family and Susie the smartest of her family. If they have ten kids, the average of those kids will regress toward the mean, but any given child could be quite far from the mean.

For populations, the equation works similarly. Hence, if a group of people with a mean IQ of 130 (who come from population with a mean IQ of 100) go off somewhere and have children, the next generation will have a mean IQ of 118. Now here’s the part that gives a lot of people trouble: the children of the children of this group, the third generation, will also have a mean IQ of 118. Why? Because the initial event changed the mean.

Isn’t it important to stress here that the first two individuals “come from population about which we know nothing more than that the entire population has a mean IQ of 100”? In particular, you have to be ignorant about their parent’s IQ. That would help people’s “trouble” with the statistics of the next generation.

It should be “towards the mean.”

Jay
I have been arguing against cognitive elitism in the reactophere on the basis that in addition to other benefits proles are a larger producer of high IQ people than elites are partly because of regression [which i now understand a bit better } but mostly because greater numbers and since these prole sired high IQs will meet and mate at university etc they will soon stabilize and improve their trait. can you calculate if this is true and to what degree. say for whites in the US or europe. my view is considered lefty which im not but you as a liberal might enjoy liberalizing the far right a bit

IQ is not everything. An extreme high share of german women have children with westafrican males. Those kids might on average become uni professors quite seldom, but popular culture, professional sports, etc. have a high demand for half-black kids, who are because of that in fact on average more successful than white german kids

For start to understand regression to mean you just need look for people around.

Family, friends, etc

Lets imagine two people having a kid who are both mixed race.

The father half white and half black. The mother is half Korean and half Ashkenazi Jew.

Would it be appropriate to just average these populations?

So if African American mean IQ is 85 and white is 100, take for the father’s mean 92.5. And if Ashkenazi mean IQ is 110 and Korean 105, take for the mother’s populational mean 107.5. Then average those two numbers out to 100, and expect 100 to be the mean that their kids would regress to?

candid observer #17,

As long as we are speaking about the breeder’s equation, we certainly have to look for groups with a tendency to inbreed. But even then it’s questionable if “academics” or “white race” or “Detroiters” would be the group of our choice. Of all three groups we can assume that they in a way tend to inbreed, but their “mean” would be completely different.

Even more so, if we are speaking about mathematical “regression to the mean” (I didn’t understand if Jayman looks at the “breeder’s equation” (or rather its outcome) as a variant of the mathematical regression or something completely different which only accidentally is subsumized under the same term).

At an individual level all probabilities are zero or one.

Nice article. We could talk about regression to the mean with professional athletes, and everybody would immediately get it, there would be no argument. But toss in intelligence as the example of luck evening out in the next generation and some folks get confused and positively cranky. Anyway keep up the good work Jayman.

What do you think about the claim that adoption studies are not really representative, because foster parents are selected, i.e. they do not show the whole variation possible within a population? I know you were very critical of this guy who claimed shared environment influence was higher when he researched poor families, but I can’t remember you have ever addressed this point (that parents in adoption studies are selected group with limited variability of environments).

There is a regression to the intellectual mean by three out of four offspring – but one in four offspring gets the best genes of both parents. This does not work for Newton and Darwin grate intellects – but it does for most others.

Generally the relevant group for determining these population means will be those groups across which a fair amount of breeding takes place. Obviously, the qualitative term “a fair amount of breeding” can be replaced by a quantitative one.

But, for example, there has been very little such breeding between any groups in SubSaharan Africa and those in Europe. Between countries in Europe, there’s been more such breeding, although it may be fair in many cases to treat each nationality as mostly a distinct group for these purposes — but, on still another hand, there may be relatively little difference on the relevant trait (such as IQ) in any case, for various obvious reasons (either both nationalities derived their IQs importantly from common ancestors, and/or they were subjected to very similar selection pressures.)

The outcome that C = 0 approaches being a reductio ad absurdum.

We won’t know that the common environmental variance has no effect for major life outcomes until you explain away the reasons the claim seems patently ridiculous. [For instance, that members of a species that is unique in the amount of long-term care it requires somehow is indifferent to the quality of that care. And if shared-environment effects IQ across birth cohorts (as by nutrition in advanced countries), what’s the plausibility that there will be no effect within cohorts?]

There seems to be a place where heritability calculations can go wrong: if the gene/common environment interaction differs from the gene/unique environment interaction. A recent exchange in Criminology suggests to me that the dispute comes down to a burden of proof argument regarding the equality or inequality of these components.

There’s something I’ve never understood. We can build categories or collectives of all kinds. For example, we can look at the child of parents as part of the population of American academics or of the white race or of the inhabitants of Detroit. Now I understand that “regression to the mean” means here, above all, regression to the mean of the parents A and B, and “regression to the mean of this or that collective” is only a comprehensive way to speak about all regressions of all individuals comprehended to the mean of their parents.
I also see that “regression to the mean of the population X” is a necessary concept as long as our contrahent Forces it upon us to speak about the future of this or that population. But it seems to be rather nonsensical if we aren’t forced to speak about this or that population.

Food for thought; it reinforces my view that seeking a mate from “a good family” is among the best ways for sons and daughters to “marry lucky.” Why anyone would ignore this, given its logical connection to happiness in life, is inscrutable.

Does your position shed any light on women who succumb to the current fad of producing children with people whose genetic contribution is probably down-market? This seems like entering Life’s Casino while yearning for Bad Luck.

Should be “recent” not “resist.”

trying to decompose this function with a best linear approximation is just mathematical jive

This is the thesis of a resist critique of heritability as applied to criminology. Has an hbder responded here?

Sorry but that is not all you need to know. Science marches on.
Want to be up to date? Check out Transgenerational epigenetic inheritance. (Easily done on Wiki. More intellectually honest checking out references).
Basically Lemark was at least a little correct. Responses to the environment can be inherited outside the schoolbook notions of neoDarwinism.
And of course any organism who figures out how to do this has a great Darwinian advantage.

I’m aware that parents aren’t perfect predictors. Obviously, meiosis is a large part of why. I don’t see the relevance to “if the parents were perfect predictors”, though.

Actually, grandparents (the average of all four, that is) are better predictors than parents

Can you point me to a good citation for this, or a good multigenerational data set?