A Stable Father Prevents the Early Onset of Puberty(?)

Connor Murphy presents below an article that I am broadly sympathetic to but the social scientist in me causes me to have reservations.  He fails to consider that pervasively influential variable:  IQ.  Many people are aware that a high IQ leads to greater educational success but far fewer are aware that it also goes with better health and longer life.

So:  There is no doubt that there is a tendency for girls to mature physically rather earlier than they used to.  There is quite a lot of estrogen or estrogen mimics in modern processed foods so that is really no surprise.  The food freaks are in a constant state of uproar about phytoestrogens, BPAs and the rest in our food. They even warn us that you can get BPAs out of babies' bottles.

But Mr Murphy has other ideas.  He thinks that stress is the culprit.  It may of course be involved but the evidence he adduces for the claim is ambiguous.  He says:

"Boys who grow up in hardship are more than four times as at risk of starting puberty aged 10 than those who grow up in safer, wealthier households. And girls who grow up disadvantaged are twice as likely to start puberty early than others."

But hardship families are very likely to be low IQ families and low IQs are associated with early maturation. American blacks, for instance, arrive at full growth about two years earlier than whites.  And chimpanzee infants go on to reach maturity as early as 8 years of age. So on balance stress has nothing to do with the tendency observed. The tendency is inborn.

Let us go on. Mr Murphy believes that the presence or absence of the father impacts female maturation:

"On average, a girl whose father divorces or separates from her mother and leaves the family home before she is 10 comes into puberty five months earlier than a girl from an intact family."

But absent fathers are by far commonest at the lowest end of the socio-economic scale.  And that is also the low end of the IQ range.  So again we most probaly have an IQ effect.  The finding can parsimoniously be explained by reference to IQ.  Both the absent father and the earlier maturation are explained by one underlying factor:  IQ

Mr. Murphy then goes on to associate the greatly increased divorce rate with earlier maturation.  But he offers no evidence to that effect. Living with a divorced single mother could well be less stressful that living in an unhappy family where parents are hostile to one-another.  Divorce is normally undertaken as the lesser evil and maybe it is in general.

So I share Mr Murphy's concerns and agree that girls benefit from a good relationship with their fathers but I doubt that he has established that.  On purely observational grounds, however, I have recently argued in favour of a similar view


The cult of modernity requires its adherents to believe that civilisation is on a linear upward path of progress and improvement. Coming to harsh conclusions about the degeneracy and sickness of our epoch is not allowed, despite the evidence of steep decline in core facets of existence like social cohesion, happiness, education, health, relationships, fertility rates, wages and governance.

Every now and then though the commissars of thought in the press make a mistake and accidentally report reality without a view to subversion, normally because they don’t realise the ramifications of what they are reporting on.

The Sydney Morning Herald recently published an extract from a book entitled "The New Puberty" by Amanda Dunn, under the title "Something is happening to our kids, and it’s time we talked about it". The subtitle was "We are seeing a major shift in the development of children, particularly girls. We cannot afford to ignore it and hope it will go away".

The extract observes that children, and particularly girls, are reaching puberty earlier. The main cause that the extract discusses is childhood obesity, i.e. previous generations did not have calorie surpluses like children do now, therefore the body is effectively receiving calories at such a rate that it "believes" it has the raw materials to begin the adolescent growth and transformation process and therefore does so earlier. In addition, the evidence indicates that menarche has also gotten earlier due to better nutrition as well, i.e. the additional calories are signalling to the body that it now has the availability of resources to create a baby.

Another article from the Herald observed that there was a clear socio-economic and stress link:

"Boys who grow up in hardship are more than four times as at risk of starting puberty aged 10 than those who grow up in safer, wealthier households. And girls who grow up disadvantaged are twice as likely to start puberty early than others."

The findings suggest that early-onset puberty may be an evolutionary response to trauma and struggle. "When we are raised in sub-optimal living conditions that means we have a higher risk of premature death," associate professor Sun said. "That means maybe we will die before we’re successfully reproductive, so we would choose an adaptive strategy to mature earlier, to have our first baby earlier, and maybe we could have more kids to ensure our genes transfer to the next generation."

This was all logical to me so far, the body is responding to stimulus (more calories and/or stress) and reacting in a manner best suited to achieving Darwinian success by passing on its genes. The thing that piqued my interest though, is that while it is well established and acknowledged that our diets are more calorie intensive and that childhood obesity is a problem nowadays, I don’t seem to recall it being as widely acknowledged that modern childhood is significantly worse or sub-optimal, and much interest in analysis of why that is the case.

Let us start with the potential causes of these more stressful childhoods that we are allowed to discuss. Most people will concede that childhood may be more stressful nowadays due to social media and hyper-sexualisation via fashion and popular culture, but these forces are not unstoppable forces of nature. Children are exposed to social media and hyper-sexualisation because adults are choosing to let them be exposed to it. We could choose not to to expose them if we were so inclined. Given the consequences of early puberty, perhaps we should be inclined, "entering puberty young (before 11) correlates with a host of problems, from teenage pregnancy to depression. Only 2% of those who do so go on to enter higher education, regardless of their parents’ IQ and educational level."

Another major societal change is the large increase in divorce and single mother households. Now this is an area you are allowed to talk about as long as we don’t attribute blame to anyone or to particular social movements:

"On average, a girl whose father divorces or separates from her mother and leaves the family home before she is 10 comes into puberty five months earlier than a girl from an intact family. But the impact of fathers is not limited to whether they are physically present. In intact families, girls reach puberty later if they have a positive rather than a negative relationship with their father; the more he is involved in her upbringing, the later she will have her first period. If the father is absent through illness or work rather than as a result of divorce or separation, the girl’s pubertal age is unaffected. Interestingly, too, an absent mother or a girl’s quality of relationship with her, does not affect the point at which she comes into puberty."

The end of that quote bordered a little bit on thoughtcrime by implying that a father has a role to play that cannot be filled by a mother, but lets press on:

"Overall, the enormous increase in the divorce rate and in single-parent households since 1960 seems very likely to have played a major role in the decreasing age of puberty. However, it is not clear precisely why an absent or emotionally unengaged father should trigger earlier puberty. The strongest clue comes from the fact that if the father leaves the family home before the girl is six, she is twice as likely to have early first periods and four times more likely to start sex early. It suggests that the disruption to the mother, a lack of cash and all the other problems that go with single parenthood, probably make the girl more likely to be emotionally needy and to be eager to be able to use sexual allure as soon as possible to make people love her. The more times a girl’s family environment changes (with the mother taking new partners) in childhood, the greater the risk of early puberty. If there are three or more new partners, a girl is five times more likely to have a teenage pregnancy."

Hmmm it might not be clear to the author of that piece why an absent or emotionally unengaged father might be a trigger, but it stands to reason that children are consciously and subconsciously aware if they are under the care and protection of an adult male, i.e. a patriarch. When they know they are not, they are more stressed as a result.

More HERE

More nonsense research on IQ. Are high IQ people more racist?

Maybe I am missing something but I think that the research below has simply shown that people who are good at recognizing patterns are good at recognizing patterns.

It is true that the Raven's IQ test is a test of pattern recognition.  Pattern recognition is a major part of IQ. So the geniuses below did a study in which people were presented with some graphics that were patterned in a certain way.  They then tested the people who had been shown the patterned graphics  to find out if they had seen and learned the pattern in the graphics.  Some had seen it. Some had not.

They found that high scorers on the Ravens pattern recognition test were more likely to have learned the pattern that had been presented to them in the graphics of the experiment. People who were good at detecting one lot of patterns were good at detecting other patterns. In other words, they confirmed that good pattern recognition was part of IQ -- which  we already knew.

So what the heck is going on?  Why did this tomfoolery get published?  It is because pattern recognition is RACIST!  If you see a pattern in people who cry "Allahu Akhbar" when they kill other people and conclude that Muslims might be more dangerous than others, that is PREJUDICE.  I would argue that it is POSTJUDICE -- judging from experience -- but that makes me a racist apparently. Recognizing patterns is BIAS!  You are not allowed to learn from experience


A new study complicates the narrative that only unintelligent people are prejudiced. The paper, published recently in the Journal of Experimental Psychology: General, suggests smart people are actually more at risk of stereotyping others.

The study consisted of a series of experiments, all of which suggested that people who performed better on a test of pattern detection—a measure of cognitive ability—were also quicker to form and apply stereotypes.

First, researchers from New York University showed 271 participants a series of pictures of red, blue, and yellow cartoon aliens with different facial features, paired with a statement of either a nice behavior (“gave another alien a bouquet of flowers”) or a rude one (“spat in another alien’s face”):

Most of the pairings were random, but two were skewed so that keen observers might pick up on a pattern: 80 percent of the blue aliens were paired with unfriendly behaviors, and 80 percent of the yellow aliens were paired with nice ones. The subjects didn’t know if the statements about the aliens were true or false. In this way, the study tried to mimic how people actually form prejudices about certain groups, like through anecdotes in the media or through portrayals in TV shows.

Later, the subjects were asked to pick which alien had committed a given behavior from a lineup:

The participants then took a test called the Raven’s Advanced Progressive Matrices, a pattern-based exam that’s a common measure of human intelligence.

The participants who were better pattern detectors were more likely to make stereotypical errors: They tended to ascribe the friendly behaviors to the wrong yellow alien, and the unfriendly behaviors to the wrong blue alien. Meanwhile, they were less likely to ascribe the behavior to a different-colored alien.

A second study showed similar results, but for measures of implicit bias. That is, smarter participants were quicker to stereotype the aliens in the course of a word-sorting task, even if they didn’t realize they were doing it.

Next, the researchers tried it with human faces, showing a new set of participants a series of computer-generated pictures of men with either wide or narrow nose bridges:

Here too, 80 percent of the narrow nose-bridge men were paired with friendly behaviors, while 80 percent of the wide nose-bridge men were supposedly unfriendly. The participants were then partnered with a new set of pictures of men for a trust game using fake money. Again, superior pattern detectors gave more money to the characters with narrow nose bridges, suggesting they had learned the stereotype about friendliness and employed it in judging the new men.

These depressing results suggest there’s a downside to being smart—it makes you risk reading too much into a situation and drawing inappropriate conclusions.

SOURCE  

Another set of findings showing that IQ scores are firmly grounded in DNA

Note that a particular DNA profile correlated .78 with educational attainment and .86 with IQ. That is about as high as you get in explaining human variation

A genome-wide association study for extremely high intelligence

D Zabaneh et al.

Abstract

We used a case–control genome-wide association (GWA) design with cases consisting of 1238 individuals from the top 0.0003 (~170 mean IQ) of the population distribution of intelligence and 8172 unselected population-based controls. The single-nucleotide polymorphism heritability for the extreme IQ trait was 0.33 (0.02), which is the highest so far for a cognitive phenotype, and significant genome-wide genetic correlations of 0.78 were observed with educational attainment and 0.86 with population IQ. Three variants in locus ADAM12 achieved genome-wide significance, although they did not replicate with published GWA analyses of normal-range IQ or educational attainment. A genome-wide polygenic score constructed from the GWA results accounted for 1.6% of the variance of intelligence in the normal range in an unselected sample of 3414 individuals, which is comparable to the variance explained by GWA studies of intelligence with substantially larger sample sizes. The gene family plexins, members of which are mutated in several monogenic neurodevelopmental disorders, was significantly enriched for associations with high IQ. This study shows the utility of extreme trait selection for genetic study of intelligence and suggests that extremely high intelligence is continuous genetically with normal-range intelligence in the population.

Molecular Psychiatry advance online publication 4 July 2017;    doi: 10.1038/mp.2017.121

Evolutionary biology:  Three theories

Evolutionary biology is an inherently speculative field and new fossil finds seem regularly to upset such theories. So I am going to concentrate on theories for which we have some solid data -- in the form of IQ scores.  I am going to look at just 3 populations for which average IQ has now been fairly securely assessed: East Asians, Europeans and Australian Aborigines. Why do the scores decline so markedly across those three groups? I think the main key is warfare or the lack of it.

Europeans are an interesting example of balance.  They have had frequent and ferocious wars with one-another but have also had substantial periods of peace. And they seem to have benefited from both.  Wars are often won by guile rather than by numbers  but that is never easy and requires ever-changing tactics.  So a general problem solving ability was selected for.  Europeans developed their IQs to help them win their many wars. A smarter tribe tended to win and therefore prosper, with more children being born for that tribe.

But the periods of peace were long enough for the pursuits of peace to thrive from time to time also.  And one of the most interesting peaceful pursuit is enquiry, scholarship, finding things out.  And because of that scholarship tends to be highly regarded.  Even in ancient Sumeria there is a record of a father bringing a fleece to give to a teacher. Which is something of an advance on an apple but we can see the same motive and the same respect.

So scholarly people tended to be well supported and hence were an economically successful group.  Sadly, many of the European scholars were celibate monks so the effect was probably much less than it might have been. The monks did however help to make scholarship prestigious so that was a useful function.

An interesting special case is the Germans.  For most of history, there was no German nation.  Germany was a geographical concept only.  It was a place where many large and small independent nations lived who all spoke a form of German.  And, ever since the Roman republic and probably before, Germans have always been warlike. And they as often made war on one-another as they did on others.  So they were heavily selected for martial ability.  Only good warriors survived.  And that selectivity did result not only in a healthy IQ but also in other advantageous attributes.  Their average IQ did not become outstanding compared with their neighbors because it was supplemented by other advantages, one of which is extreme: innovativeness.

It was probably the desirability of military flexibility that made Germans into master innovators, something I have written at length about previously. Leftist psychologists go to great lengths to isolate important intellectual abilities that are not captured by IQ tests but their suggested alternatives mostly reduce to absurdity.  So it is amusing that one of the few genuine alternatives is innovativeness.  That Germans are the masters in that attribute must grind a few gears, however.

Hollywood war movies portray German troops as rigid and robotic bunglers so my characterization of them as flexible will no doubt be a surprise to non-historians.  In fact however, flexibility in tactics was preached in Vom Kriege,  that great Prussian bible of military doctrine by Clausewitz, written early in the 19th century.  The big bunglers of WWII were allied troops.

Particularly in the case of the Prussians (North-Eastern Germans), their martial tendencies were channeled in another direction as well:  into a military personality, with self-discipline being a major part of that. For instance, punctuality requires self discipline and Germans are famous for that.

Speaking more generally, it once used to be said that you just had to drop any German into a military uniform and he immediately became the perfect soldier.  And the exploits of the Wehrmacht in WWII were amazing.  Although heavily outnumbered they very nearly won, despite the large handicap of Corporal Hitler's overall inept leadership.

Just to give you the flavor of that, the British air ace with the highest number of enemy aircraft shot down was "Johnnie" Johnson, with 38 "kills". By comparison, Erich Hartmann of the Luftwaffe had 352 "kills". A similar ratio was not unknown in WWII tank battles.

But Germany did have periods of peace so the arts of peace thrived there as well.  It might be noted that the contributions to the arts made by Germans as a group were however very unevenly distributed, with Austria being by far the greatest contributor -- particularly in music -- and Prussia the least. To this day, about two thirds of the classical repertoire in music was composed in Austria (Haydn, Mozart, Beethoven, Schubert etc.).

So what is distinctive about Austria?  It was a large empire that got big not by war but by intermarriage of its royal family with other royal families.  They did have wars -- particularly with invading Prussians -- but life in the empire was mostly peaceful.  So "useless" but beguiling things like music and literature could thrive.

And up to WWII, Vienna, the capital of Austria, was THE great city.  It was the intellectual capital of the world.  Most of the eminent philosophers (e.g. Schlick, Wittgenstein), psychologists (e.g. Freud, Jung), Economists (e.g. Boehm von Bawerk, Mises) and artists (e.g. Klimt, Klee) were there. And Vienna was also prominent in new music. It was the home of a great new musical artform, the operetta -- with operettas by composers such as Strauss and Kalman generating many perennially popular songs.  Dutch musical entrepreneur Andre Rieu is a great user of songs from operetta.

China

Compared with Europe, China had long periods of peace under the various dynasties.  So peaceful pursuits could flourish.  And one of those pursuits was scholarship, a much respected pursuit. So China developed its famous civil service examinations, which gave you access to the Chinese elite.  You reached the top in China not by the sword but by the ink brush. And that made scholarship universally respected and aspired to.

And a major factor in scholarly achievement is IQ. So it was the high IQ section of the Chinese population who got all the gravy. They flourished economically and thus tended to have more children.  So IQ was heavily selected for in China over many generations. And so we have the finding today that the Chinese are roughly half a standard deviation higher in average IQ than are Westerners.

And Chinese civilization was much admired in Korea and Japan.  Confucian thinking was adopted there. Chinese bureaucracy, culture, religion, and philosophy were closely studied.  Japan had a particular advantage there.  The Tokugawa shogunate gave Japan over 200 years of peace, an unprecedented achievement. So peaceful pursuits were of particular interest there as well. The Chinese model was largely adopted, with similar results.  So China, South Korea and Japan are closely similar in IQ.

Which leads to an interesting contrast:  Other East Asians, such as the Chinese and Vietnamese do quite poorly on average IQ.  How come?  They all look the same to us!  The Philippines is an easy answer. They are separated from China by rather a lot of ocean.  China did have some influence but the Filipinos mostly went on with their own ways.

And for Vietnam, the problem was the neighborhood bully:  China.  Vietnam was a minor issue in China but China was a big issue in Vietnam.  Little Vietnam kept being invaded from next-door China.  And because China could muster far more troops than Vietnam, Vietnamese had to develop as warriors if they wanted to keep China at bay. And they did.  Like Germans, the Vietnamese became a warrior race -- as both France and the USA found out in the 20th century.  So there was much less scope for peaceful pursuits in Vietnam. Keeping out foreigners became the Vietnamese specialty. And they are still good at that.

Aborigines

And so on to Australian Aborigines, who register one of the lowest average IQs that have been found.  And their unusual situation was very clear: isolation. They had virtually no contact with the outside world for as much as 60,000 years. So they developed with reference to the Australian environment only. And Australia as it was before white settlement tended to be an unforgiving place.  It was hard to make a living there.  For a primitive people the food supply was always precarious.  So the environment was the big challenge and the big shaping influence.  And shape them it did. 

Aborigines are not inferior to others intellectually.  They have just deveoloped different intellectual skills.  The skills they have are a very poor at dealing with IQ tests or modern life generally but are superbly adapted to their lives before the white men came along.  Each tribe usually had a fairly wide geographic range that they wandered over.  They had to.  They were hunter/gatherers, not farmers.  So food was scarce everywhere, particularly in the large dry areas of Australia.  So detecting from afar and creeping up on juicy herbivores was the big requirement for life.

So Aborigines developed a quite eerie ability to "read" and remember the landscape. If a few leaves on the ground had moved in the last day or two, an Aborigine would notice that as a message that there was an animal nearby.  He could probably even say which sort of animal. You have to see it to believe it.  They just have enormous visual abilities and a vast visual memory.

That extraordinary skill was in fact very useful to the white man in earlier days. It was useful in tracking down fugitives and criminals.  So the phenomenon of the "black tracker" arose.  Aborigines were hired by police to find people who would otherwise be unfindable.  An evildoer might think that he had made good his escape and he would be right in thinking that -- UNTIL the police put a black tracker on his trail.  The black tracker would see a clear trail that was invisible to whites.  Just a slightly turned leaf would be enough. So crooks who thought they were safe were often surprised to find police knocking on their door.

I could go on.  The way the environment often underlies human differences is fascinating.  I will forbear from mentioning Africans however.

Diversity doesn't make racial differences magically disappear

The point made below is unusually realistic for The Guardian but the author still has no idea why it is so.  He is perfectly right that minority/majority status does little to make one prosperous or not.  Whites are a prosperous majority in the USA and a prosperous minority in Brazil.  How come?  Shouldn't being in a majority always mean dominance in various ways?  Why are some minorities prosperous?

The fact that majority/minority status does not determine your wealth or other advantage, seriously undermines the common Leftist claim that American blacks are poor only because whites keep them down.

The fact is that it is your personal competence at economic tasks that generally dictates your economic status.  In general, whites are better at doing things that other people are willing to pay for -- so will always be richer than the less economically competent.  And why are whites more competent?  If you look at average IQ scores the answer is plain.  Whites are much smarter in general and they get it from their parents

Short of a race war that will not change.  And majorities don't always win wars either, as the Hutus found out


We can't screw our way beyond racism. Many think mixed-race babies and browner demographics will automatically usher in a post-racial world. They interpret the projections of a "majority-minority" shift in our nation – now set to take place in 2044 – as a sign of guaranteed progress. Changing faces in the US are seen as anti-racist destiny. But don't overestimate the power of this post-racial cocktail.

Jordan Peele's brilliant film Get Out reminds me of the importance of questioning overly optimistic narratives of racial progress. Made by someone who has been open about being biracial and married to a white women, this film creatively uses the genre of horror to depict the persistence of racism through a story about an interracial couple. In many ways, it can be seen as a strident critique of a liberal brand of racism that has blossomed in the post-Obama era.

The perspective that multiracial demographics naturally erode bias and inequality tends to lack historical and global perspective. Consider Brazil. There, white people are a minority – but are still dominant. Despite being outnumbered, their incomes are more than double than that of Afro-descendants; white men are also vastly over-represented in Brazil's new government.

If more mixed people guarantee greater tolerance, then Brazil – and most of Latin America – should be a racial paradise. Although a great degree of 'mestizaje' or racial mixing has taken place since the time of conquest, Indigenous and Afro-descendent people in Latin America remain disproportionately poor, discriminated against, and locked out from opportunity.

Sociologist Eduardo Bonilla-Silva, in his book Racism without Racists, has speculated whether the racial order in the US might eventually resemble that of Latin American and Caribbean nations. In this case, white supremacy and racial stratification will continue to operate in the US even as it becomes a "majority-minority" nation.

Even the idea of a "majority-minority" shift obscures the fact that the US will be better described as a racial plurality. It's not as if non-whites constitute one homogenous group.

The legacy of blanqueamiento ("whitening") in Latin America demonstrates that ideals of multiraciality can run alongside white supremacy. This theory, widely adopted and practiced by Latin American nations at the turn into the 20th century, encouraged racial mixing for the sake of moving entire populations towards whiteness. This is a reminder that desires for a mixed future can be, and have sometimes been, grounded in anti-blackness.

To be sure, all of this does not discredit the importance of diversity and the unique perspectives that people of multi-ethnic/racial backgrounds possess because of their social location. Speaking of the consciousness of the mestiza, Chicana thinker Gloria Anzaldתa writes: "In our very flesh, (r)evolution works out the clash of cultures."

People with mixed backgrounds can disrupt notions of purity that undergird race and synthesize vast cultural traditions. People with mixed backgrounds can also internalize and carry out racism.

Instead of reducing mixed people to being inevitable harbingers of a post-racial future, there needs to be an acknowledgement of agency in how mixed people choose to relate to the problem of racism and how society, in turn, chooses to receive mixed people.

Merely looking optimistically into the future erases the past that the US has with multiraciality. The figure of the "Tragic Mulatto/a" arose in US literature and film precisely because our racial architecture is based upon a series of denials. Speaking to the West Indian Student Center in London in 1968, James Baldwin captured this incisively:

"What is really happening is that brother has murdered brother knowing it was his brother. White men have lynched Negroes knowing them to be their sons. White women have had Negroes burned knowing them to be their lovers … the American people are unable to face the fact that I'm flesh of their flesh, bone of their bone."

Baldwin exposes the naןve belief that racial intimacy and mixture are some inevitable bulwark against racism.

Demographics are not destiny. Having a multiracial background may no longer be necessarily tragic but it is not automatically heroic.

What is the racial future of this nation? As a social construct tied to political and economic power, racism has proven itself adept at employing difference to prolong its entrenchment. Notwithstanding Trump's efforts to engineer a white nationalist future, where we go from here is not determined. It's up to us. It depends on what we all decide to do.

SOURCE

Very strong study shows health advantages for high IQ people across the board

This sort of finding emerges so often that I should probably stop putting them up.  But when the Left keep dismissing IQ as meaningless, what am I to do?

Childhood intelligence in relation to major causes of death in 68 year follow-up: prospective population study

Ian J Deary et al.

Abstract

Objectives: To examine the association between intelligence measured in childhood and leading causes of death in men and women over the life course.

Design: Prospective cohort study based on a whole population of participants born in Scotland in 1936 and linked to mortality data across 68 years of follow-up.

Setting: Scotland.

Participants: 33 536 men and 32 229 women who were participants in the Scottish Mental Survey of 1947 (SMS1947) and who could be linked to cause of death data up to December 2015.

Main outcome measures: Cause specific mortality, including from coronary heart disease, stroke, specific cancer types, respiratory disease, digestive disease, external causes, and dementia.

Results: Childhood intelligence was inversely associated with all major causes of death. The age and sex adjusted hazard ratios (and 95% confidence intervals) per 1 SD (about 15 points) advantage in intelligence test score were strongest for respiratory disease (0.72, 0.70 to 0.74), coronary heart disease (0.75, 0.73 to 0.77), and stroke (0.76, 0.73 to 0.79). Other notable associations (all P less than 0.001) were observed for deaths from injury (0.81, 0.75 to 0.86), smoking related cancers (0.82, 0.80 to 0.84), digestive disease (0.82, 0.79 to 0.86), and dementia (0.84, 0.78 to 0.90). Weak associations were apparent for suicide (0.87, 0.74 to 1.02) and deaths from cancer not related to smoking (0.96, 0.93 to 1.00), and their confidence intervals included unity. There was a suggestion that childhood intelligence was somewhat more strongly related to coronary heart disease, smoking related cancers, respiratory disease, and dementia in women than men (P value for interactions less than 0.001, 0.02, less than 0.001, and 0.02, respectively).Childhood intelligence was related to selected cancer presentations, including lung (0.75, 0.72 to 0.77), stomach (0.77, 0.69 to 0.85), bladder (0.81, 0.71 to 0.91), oesophageal (0.85, 0.78 to 0.94), liver (0.85, 0.74 to 0.97), colorectal (0.89, 0.83 to 0.95), and haematopoietic (0.91, 0.83 to 0.98). Sensitivity analyses on a representative subsample of the cohort observed only small attenuation of the estimated effect of intelligence (by 10-26%) after adjustment for potential confounders, including three indicators of childhood socioeconomic status. In a replication sample from Scotland, in a similar birth year cohort and follow-up period, smoking and adult socioeconomic status partially attenuated (by 16-58%) the association of intelligence with outcome rates.

Conclusions: In a whole national population year of birth cohort followed over the life course from age 11 to age 79, higher scores on a well validated childhood intelligence test were associated with lower risk of mortality ascribed to coronary heart disease and stroke, cancers related to smoking (particularly lung and stomach), respiratory diseases, digestive diseases, injury, and dementia.

BMJ 2017; 357 doi: https://doi.org/10.1136/bmj.j2708

More genes linked to IQ

Because IQ is linked to so much else, psychometricians have long expected it to be polygenetic: Many genes have an input into it.  I have always favoured the view that a high IQ is simply one aspect of general biological good functioning.  The brain is just another organ of the body, after all. So if that is the case, the number of genes linked to IQ should be very large indeed.  So the work below is just a first step.

Various reports of this study distort its results --  with the NYT in the lead on that.  So let me answer them here: 

The NYT says: "These genes do not determine intelligence, however. Their combined influence is minuscule".  That is exactly the opposite of what the study found.  I append the journal abstract below so readers can check for themselves.  The authors found that their 52 genes explained 5% of the variance in IQ.  That per cent of variance explained is about normal in psychological research and has been used to support many claims of causality.  And the 5% will rise as more genes are analysed.

Other reports misunderstood the links to Alzheimers and Schizophrenia.  The study found that people with high IQ genes had LESS Alzheimers and Schizophrenia, not more.  It is interesting, however, that high IQ genes are associated with autism.  As is well known, autistic people often have extreme mental abilities in some fields, so the finding is not too surprising.  Most high IQ people are not autistic, however.

I liked the finding that high IQ people are tall, thin and unlikely to smoke. I am an example of that.  I am 5'10", was very skinny in my early life and have never smoked. 5'10" is not that tall these days but when I was born 73 years ago it was. The average male height in Australia has increased 3" in the last 50 years.


Intelligence is one of the most investigated traits in humans, but so far, only a handful of genes have been associated with the trait.

Now, researchers have made a major advance in understanding the genetic underpinnings of intelligence, uncovering 52 genes for the trait, 40 of which are new discoveries.

In particular they found that many people with these genes are more likely to have other traits, including being tall, thin and unlikely to smoke.

Scientists hope the findings could provide new biological insights into brain function and understanding, and help to define the genetic component of IQ.

The findings also turned up a surprising connection between intelligence and autism that could one day help shed light on the condition's origins.

"For the first time, we were able to detect a substantial amount of genetic effects in IQ," said Danielle Posthuma, a researcher at the Center for Neurogenomics and Cognitive Research in Amsterdam, and the main architect of the study. "Our findings provide insight into the biological underpinnings of intelligence," she told AFP.

An international research team led by Vrije Universiteit Amsterdam studied genetic data from over 78,000 individuals. The data included information on DNA genotypes and intelligence scores, which led the team to discover new genes and biological routes for intelligence.

Despite high heritability estimates of 45 per cent in childhood and 80 per cent in adulthood, until now, only a few genes had been associated with. But the new study uncovered 40 new genes, most of which are mainly expressed in brain tissue.

Professor Posthuma said: 'These results are very exciting as they provide very robust associations with intelligence. 'The genes we detect are involved in the regulation of cell development, and are specifically important in synapse formation, axon guidance and neuronal differentiation.

'These findings for the first time provide clear clues towards the underlying biological mechanisms of intelligence.'

The results showed that people with the genes were more likely to have high educational achievements, and were also likely to be taller, not to smoke, and to have autism spectrum disorder.

In contrast, people with the intelligence genes were less likely to have Alzheimer's disease, depressive symptoms, smoking history, schizophrenia, high body mass index, or obesity.

Dr Suzanne Sniekers, who also worked on the study, said: 'These genetic correlations shed light on common biological pathways for intelligence and other traits.

'Seven genes for intelligence are also associated with schizophrenia; nine genes also with body mass index, and four genes were also associated with obesity. 'These three traits show a negative correlation with intelligence.

'So, a variant of gene with a positive effect on intelligence, has a negative effect on schizophrenia, body mass index or obesity.'

The researchers stress that future studies will be needed to clarify the exact role of these genes in intelligence in order to gain a more complete picture of how genetic differences lead to differences in intelligence.

Professor Posthuma added: 'The current genetic results explain up to five per cent of the total variance in intelligence.

'Although this is quite a large amount of variance for a trait as intelligence, there is still a long road to go: given the high heritability of intelligence, many more genetic effects are expected to be important, and these can only be detected in even larger samples.'

SOURCE    

Genome-wide association meta-analysis of 78,308 individuals identifies new loci and genes influencing human intelligence

Suzanne Sniekers et al.

Intelligence is associated with important economic and health-related life outcomes1. Despite intelligence having substantial heritability2 (0.54) and a confirmed polygenic nature, initial genetic studies were mostly underpowered3, 4, 5. Here we report a meta-analysis for intelligence of 78,308 individuals. We identify 336 associated SNPs (METAL P < 5 × 10−8) in 18 genomic loci, of which 15 are new. Around half of the SNPs are located inside a gene, implicating 22 genes, of which 11 are new findings. Gene-based analyses identified an additional 30 genes (MAGMA P < 2.73 × 10−6), of which all but one had not been implicated previously. We show that the identified genes are predominantly expressed in brain tissue, and pathway analysis indicates the involvement of genes regulating cell development (MAGMA competitive P = 3.5 × 10−6). Despite the well-known difference in twin-based heratiblity2 for intelligence in childhood (0.45) and adulthood (0.80), we show substantial genetic correlation (rg = 0.89, LD score regression P = 5.4 × 10−29). These findings provide new insight into the genetic architecture of intelligence.

Nature Genetics. (2017) doi:10.1038/ng.3869