Friday, January 29, 2016
IQ and health: More discomfort for the Left
The Left hate IQ because it conflicts with their crazy "all men are equal" gospel. So they never give up hope of discrediting the whole concept. They have tried all sorts of arguments but the phenomenon is so robust and so pervasive that it has easily survived all the assaults aimed at it. It cannot be explained away.
But the unending stream of scientific findings showing how important IQ is to one's life chances has now mostly driven Leftists back to their most basic defence-mechanism: Denial. They just refuse to think or talk about it. They act as it doesn't exist -- with results that range from the hilarious to the disastrous.
For those of us who think reality is important, however, the recent report below should be of interest. The basic finding -- that high IQ people are healthier -- actually dates back to the 1920s but it is nice to see current research coming to the same conclusion. That's the pesky thing about IQ: Careful research into it always leads to the same conclusion
The findings below in fact support something I have been saying for a long time: That high IQ is an index of general biological fitness. The brain is just one of the body's organs and if it is functioning well, it is likely that the rest of the body is functioning well too. As a great Rabbi once said: "To him that hath, more will be given him" (Matthew 13:12). Jesus was not an egalitarian
Clever people are more likely to be healthier than those with a lower IQ due to a genetic link between how our bodies manage diseases and intelligence.
Researchers from Scotland analysed data from around 100,000 people held in the UK Biobank.
They compared each person's mental test data with their genome and found that traits linked to disease and thinking skills shared the same genetic influences.
In particular, the international team of scientists led by the University of Edinburgh found 'significant negative genetic correlations' between a person's education and verbal-numerical reasoning skills and Alzheimer's disease, coronary artery disease and strokes.
In other words, well-educated people who excel at problem solving are less likely to contract the conditions.
Clever people were also less likely to be overweight. [I like that one]
The team found there was a negative genetic correlation between body mass index and verbal-numerical reasoning, while a greater risk of high blood pressure was associated with lower education.
The researchers explained: 'Our results provide comprehensive new findings on the overlaps between cognitive ability levels, genetic bases for health-related characteristics such as height and blood pressure, and physical and psychiatric disorders even in mostly healthy, non-diagnosed individuals.
'They make important steps toward understanding the specific patterns of overlap between biological influences on health and their consequences for key cognitive abilities.
'For example, some of the association between educational attainment - often used as a social background indicator - and health appears to have a genetic [cause].'
However, the team added: 'It has not escaped our notice that there are multiple possible interpretations of these genetic correlations.
The results of the latest Edinburgh-based study build on previous research that found 95% of the link between intelligence and life expectancy is genetic.
Using a study on twins, experts from the London School of Economics found brighter twins tend to live longer and noted the pattern was much more pronounced in fraternal - non identical - twins, than identical pairs.
By looking at both fraternal twins - who only share half their twin's DNA - with identical twins, researchers were also able to distinguish between genetic effects and environmental factors, including housing, schooling and childhood nutrition.
'Not only might particular genes contribute both to cognitive and health-related traits, but genetic variants relating to health conditions could have indirect effects on cognitive ability and vice versa, [on] lifestyle choices.'
As an example, poorly educated people may be less likely to make informed choices about what they eat and how much they drink.
The study is not all good news for intelligent people, though.
The team did find that the genetic variants associated with obtaining a degree were also related to a higher genetic risk of schizophrenia, bipolar disorder and autism.
Edinburgh University Professor Ian Deary, who led the research, said the study could help in understanding some of the links between low levels of cognitive function and poor health.
Psychologist Saskia Hagenaars, who worked on the research, added: 'The study supports an existing theory which says that those with better overall health are likely to have higher levels of intelligence.'
The UK Biobank, launched in 2007, is a major long-term investigation into the respective contributions of genetic predisposition and environmental exposure in the development of disease.
The findings are published in the journal Molecular Psychiatry.
Posted by jonjayray at 8:33 AM
Sunday, January 24, 2016
Poverty and IQ again
Charles Murray showed a couple of decades ago that the poor tend to have lower IQs. And it was hardly a surprise that being dumb might keep you poor. But the Left purport to love the poor so Murray was furiously attacked over his findings -- though he had not in fact said most of the things he was alleged to have said. It was a very cautious and scholarly book rather than any kind of polemic. The Leftist rage at Murray finally exhausted itself but Murray still has his marbles and is an active Facebooker so I imagine that he could give you more details of the "controversy".
Murray seems to have won the war, however. Leftists do now occasionally mention the inverse correlation between lower social class and IQ. Rather than say that low IQ causes poverty, however, they try to prove that poverty causes low IQ. I dealt with the latest such attempt a couple of weeks ago.
There was another attempt in that direction back in 2013 that I commented on at the time. It claimed that poverty was very stressful and that the stress prevented your brain from working properly. I would have thought that middle-class careerists were under the greatest stress but let's leave that for the moment. The title of the article was "Poverty Impedes Cognitive Function". There is a journalistic rendering of the claim here.
I put the findings in context at the time, showing that the conclusions did not follow from the reported evidence. I was not aware, however, that Jelte Wicherts also looked at the study around the same time. Now that J.P. Rushton is deceased, Wicherts is probably the man who knows the research on IQ better than anyone else. And he is fair. If someone puts up a celebratory claim about IQ, Wicherts will look at that critically, and if someone puts up claims that disrespect IQ Wicherts will look at that critically too. So I have a very favourable impression of Dr. Wicherts.
I have now come across his criticism of the 2013 study and it does not disappoint. I reproduce the abstract below:
"Mani et al. (Research Articles, 30 August, p. 976) presented laboratory experiments that aimed to show that poverty-related worries impede cognitive functioning. A reanalysis without dichotomization of income fails to corroborate their findings and highlights spurious interactions between income and experimental manipulation due to ceiling effects caused by short and easy tests. This suggests that effects of financial worries are not limited to the poor"
Posted by jonjayray at 8:34 AM
Friday, January 8, 2016
Having a big family makes your children either badly behaved or low achievers at school, study claims
The academic article underlying the popular report below is "The Quantity-Quality Trade-off and the Formation of Cognitive and Non-cognitive Skills". In my usual pesky way, I have had a look at it
I don't have the time to look in great detail at this quite complex study so I will content myself with a couple of basic observations. For a start, the finding is unusual. Other studies have found no effect of family size.
The problem, if there is one, appears to be an artifact of social class, though the authors are not allowed to mention that naughty word, of course. The effect seems mostly found among the poor, who are also less bright and who are also more likely to have big families.
And here's the tricky bit: Mention of poverty in America immediately calls to mind the naughtiest word of all: race. Did the authors control for race? Would the effect drop to insignificance if you looked at whites only? The Abstract of their current paper does not mention that word. But here's the kicker. There is also online what appears to be a preprint of the paper. And that DOES mention the word. And they DID find that race had a big effect. The effect of family size was primarily seen among persons of sub-Saharan African ancestry ("blacks" in non-academic language).
And the effects overall were not large. The word "IQ" is another word that may not be mentioned in polite circles. It is too easily understood. But their statistics can be translated into IQ. And the result is that we are looking at only about an IQ change of 1.5 IQ points. So the whole thing hardly matters anyway.
The takeaway is that in most families parents can have as many children as they like without concern about dumbing their kids down
Finally: I don't like to do this but I feel that I must place this study in the context of the current uproar in psychology about the high rate of unreplicable results and the associated topic of research ethics. It is now clear that many scientists do not tell the full truth about their research results -- for various reasons.
In that context, any concealment of findings calls into question the integrity of the research and the integrity of its authors. And since scientific communication depends heavily on trust, any attempt at concealment of findings -- as we see in the published abstract of this study -- strongly suggests that the work was not honestly reported and should therefore be disregarded. I am not being cynical in saying that the abstract IS the article for most readers of academic journal articles. Only specialists in that field plough through the whole thing
In the circumstances it is open for one to conclude that the real findings concerned blacks only but that was too unpalatable ("politically incorrect") to publish. So that problem was "worked around" in one or more ways
A new study has found that for every additional child born, the others are more likely to suffer poor cognitive abilities and behavioural problems afterwards.
Boys were more likely to misbehave while girls saw their performance in maths and reading skills dip.
Using data from 1986 to 2012 taken by the National Longitudinal Survey of Youth (NLSY) and by the Children and Young Adult Survey, three economists analysed how older siblings performed before and after a younger sibling was born.
They looked at the number and timing of births into a family and matched these to various mental and behavioural traits.
Levels of parental engagement were also crucial - with factors like how often families eat meals together, one-on-one time with each child, affection and the safety of the home also affecting how a child performed.
As families got bigger, the time spent with each child reduced, which has been linked to worse outcomes for children, they found.
'Our fixed effect estimates indicate that the arrival of a younger sibling reduces measures of parental investment as well as cognitive and non-cognitive outcomes of older children by approximately one-tenth of a standard deviation,' the research paper said.
The study was conducted by economists Chinhui Juhn, Yona Rubinstein, and C. Andrew Zuppann, who questioned whether the 'quantity' of children would effect the 'quality' of their upbringing.
It discovered that parental investment in older kids fell by 3 percentile points after a young child is born, while cognitive scores fell by 2.8 percentile points and behavioural problems increased.
'We have documented a significant trade-off between quantity and quality of children for NLSY mothers and their children. 'On average, children in larger families have lowered parental investment and worse cognitive and non-cognitive outcomes. '
Other factors found to influence the outcomes was the mother's intelligence and economic well-being.
Mothers were asked to take the Armed Force Qualification Test (AFQT), used by the military to assess skills including reading and reasoning.
Those who scored badly saw a larger drop in cognitive scores when they had their second child.
Posted by jonjayray at 5:18 PM
Thursday, January 7, 2016
Does poverty reduce your IQ?
Only in America, allegedly. That poverty CORRELATES with low IQ has long been known. Poor people are often that way because they make dumb decisions -- spending all their money on beer, drugs and cigarettes, for instance. A much more interesting question, therefore is whether poverty CAUSES low IQ. We know that low IQ causes poverty but does poverty cause low IQ?
A recent very extensive and very sophisticated study set out to examine that -- and the results have been reported enthusiastically -- as showing that poverty DOES have an effect on IQ. I reproduce a popular report of it below.
I have however, in my usual pesky way, gone back to the underlying academic journal article and read it. I have even looked at the numbers! Despite its great methodological care and statistical complexity, it is an amusing example of failing to do something that the best journals now recommend: Pre-register your expectations. Studies that do not do that are very prone to data dredging effects -- looking for any correlation in the data that seems large and changing your hypothesis to say that's what you expected all along.
And the authors below did not pre-register their expectations. They data-dredged. After all the hard work they did in gathering and analysing their data, they initially found NO EFFECT of poverty on IQ. So they desperately looked at their data to see what was in fact going on. And they found that if they used U.S. data only, there was a weak effect in the direction expected.
Findings that were not pre-registered can of course still be accepted and there are long-standing procedures to allow for data dredging -- adopting an experiment-wise error-rate approach, for instance. That is however very rarely done in fact. It would take all the fun out of a lot of research. But some approach to allowing for that sort of thing is now being given emphasis in journal review policies. In simple words, a much stronger effect is required for an unplanned relationship to be taken seriously. A weak relationship could be just a random oscillation.
The effects reported below were however very slight so I think that by current academic standards we should accept the null hypothesis. We should conclude that poverty does NOT demonstrably affect IQ.
I don't like to flog a dead horse but a second defect in the study is that the findings were not controlled for race. Could race alone account for the aberrant U.S. results? Knowing as we do how atypical are the IQs of persons with sub-Saharan African ancestry ("blacks", to use non-academic language) the researchers should clearly have excluded blacks from all analyses on the grounds that they are a quite separate population requiring study in their own right. The authors admit this but did not do it
The original study is rather misleadingly titled: "Large Cross-National Differences in Gene × Socioeconomic Status Interaction on Intelligence"
Poverty has long been linked with lower levels of intelligence, especially among children, but a new study has suggested its impact may depend on where you live.
Scientists believe a person's intelligence is formed by a complex interplay between the genes they inherit from their parents and the environment they grow up in.
But a study of twins has determined that childhood poverty appears to 'dampen down' the potential contained within a person's genes - and the situation varies from country to country.
The study, conducted by researchers at University of Texas at Austin and the University of Edinburgh in Scotland, found people born in the US tend to suffer the effects of poverty more.
Elsewhere, the link between poverty and a lower IQ was less noticeable in Western Europe and Australia, and in fact the opposite may be true in the Netherlands.
The study, which is published in the journal Psychological Science, analysed the findings of 14 peer-reviewed papers.
Combined, they drew upon almost 25,000 sets of twins and siblings from the US, Australia, England, Sweden, Germany and the Netherlands.
The researchers said the differences between the US and European countries may be due in part to more universal access to healthcare, which has helped to close some socioeconomic gaps.
Differences in the education systems in the countries may also play a role.
The researchers behind the study added that the results could prove useful in helping to tackle gaps between socioeconomic groups.
They said that providing more uniform access to education and healthcare can counter and even reverse the negative effect of poverty on genes involved in IQ.
Posted by jonjayray at 8:35 AM