Thursday, April 29, 2010

Salt is controversial

NewScientist magazine claims that a salt conspiracy has planted articles in the NY Times:
There's no doubt about the health dangers of salt

SALT hidden in food kills millions of people worldwide. Reducing dietary salt is therefore important for public health; it is also one of the cheapest and easiest ways to save lives. So why are efforts to cut dietary salt being met with fierce resistance?

First the facts. Decreasing salt intake substantially reduces blood pressure, thus lowering the risk of heart attacks and strokes. An analysis of all the available evidence, published in 2007, suggested that reducing salt intake around the world by 15 per cent could prevent almost 9 million deaths by 2015. ...

Most people agree that even in free-market economies, governments have a duty of care. This is especially true for children, who are particularly vulnerable to high salt intake.

This is the ethical justification for public health interventions in salt consumption. Governments legislate to make public spaces smoke-free, and they mandate cholera-free drinking water. They should also aim to progressively reduce the salt hidden in food. ...

The salt industry's annual turnover is several billion dollars and it has no plans to downsize. Thus, in advance of the new US guidelines, articles have appeared in The New York Times and elsewhere claiming that the evidence for reducing salt is not clear-cut.

This controversy is fake. The evidence for salt reduction is clear and consistent.
I am suspicious any time some left-wing conspiracy-monger tries to promote some far-reaching policy on the grounds that there is a scientific consensus.

Salt is not comparable to cholera. Cholera is undesirable and harmful in all quantities. Salt is essential to life, and has no known harm to children and adults with normal blood pressure.

A science article should be telling us the trade-offs, not lecturing us on how govt authorities should be telling us what to eat. Salt is in food for reasons, and not just because of pressure from the salt lobby. Whether it is for taste or as a preservative, reducing salt will have its costs. Whether it is worth the costs is a political question, not a scientific one.

Tuesday, April 27, 2010

Poor study on teacher quality

AAAS Science magazine reports this study:
Teacher Quality Moderates the Genetic Effects on Early Reading
J. Taylor, A.D. Roehrig, B. Soden Hensler, C.M. Connor, C. Schatschneider

Children’s reading achievement is influenced by genetics as well as by family and school environments. The importance of teacher quality as a specific school environmental influence on reading achievement is unknown. We studied first- and second-grade students in Florida from schools representing diverse environments. Comparison of monozygotic and dizygotic twins, differentiating genetic similarities of 100% and 50%, provided an estimate of genetic variance in reading achievement.
This is okay so far, except that "reading achievement" seems to be just reading aloud from a book, without testing comprehension.
Teacher quality was measured by how much reading gain the non-twin classmates achieved. The magnitude of genetic variance associated with twins’ oral reading fluency increased as the quality of their teacher increased. In circumstances where the teachers are all excellent, the variability in student reading achievement may appear to be largely due to genetics. However, poor teaching impedes the ability of children to reach their potential.
No, this does not measure teacher quality. One classroom might do better than another classroom for many reasons besides teacher quality, such as the IQ of the classmates and whether misbehaving students are disrupting the class.

The full paper is behind a paywall, but I checked it, and it admits that the study just assumed that test scores reflect teacher quality.

This is a simple twin study to quantify nature-nurture differences. Apparently, it had to slap on some bogus conclusions about teacher quality in order to get it published in a leftist science magazine.

Dead people had bad habits

AP reports on a widely publicized study:
Four common bad habits combined — smoking, drinking too much, inactivity and poor diet — can age you by 12 years, sobering new research suggests.

The findings are from a study that tracked nearly 5,000 British adults for 20 years, and they highlight yet another reason to adopt a healthier lifestyle.

Overall, 314 people studied had all four unhealthy behaviors. Among them, 91 died during the study, or 29 percent. Among the 387 healthiest people with none of the four habits, only 32 died, or about 8 percent.

The risky behaviors were: smoking tobacco; downing more than three alcoholic drinks per day for men and more than two daily for women; getting less than two hours of physical activity per week; and eating fruits and vegetables fewer than three times daily.
No, this study does not prove that those bad habits age you. Maybe the exercise does not make you healthier or make you live longer at all. Maybe the folks who are in poor health are about to die are physically incapable of exercise. Then this study would make it appear that exercising is making people live longer, but the exercise could be just a symptom, not a cause.

Monday, April 26, 2010

Virginia stamps out coded message

The Wash. Post reports:
A few hours later, the DMV agreed that the plate contains a coded message: The number 88 stands for the eighth letter of the alphabet, H, doubled to signify "Heil Hitler," said CAIR's Ibrahim Hooper. "CV" stands for "Confederate veteran" -- the plate was a special model embossed with a Confederate flag, which Virginia makes available for a $10 fee to card-carrying members of the Sons of Confederate Veterans. And 14 is code for imprisoned white supremacist David Lane's 14-word motto: "We must secure the existence of our people and a future for white children."

The giveaway that something was amiss, Hooper said, was the truck itself. An enormous photo of the burning World Trade Center towers covers the entire tailgate, with the words: "Everything I ever needed to know about Islam I learned on 9/11."
Where I live, thousands just celebrated April 20 because 4-20 is a coded message for dope smoking. What if 9-11 becomes a coded message for, "Everything I ever needed to know about Islam"?

Friday, April 23, 2010

New missing link

Here is a picture of the latest missing link, a Neanderthal half-breed. Nature reports:
Archaic humans such as Neanderthals may be gone but they're not forgotten — at least not in the human genome. A genetic analysis of nearly 2,000 people from around the world indicates that such extinct species interbred with the ancestors of modern humans twice, leaving their genes within the DNA of people today.
The theory is that today's Europeans are descended from people who migrated out of Africa and then interbred with Neanderthals. Sounds dubious to me, but I am sure we will hear more about this. There is current a project to sequence the Neanderthal genome, and we should be hearing some results soon.

There is also a far-fetched theory that autism is caused by Neanderthal genes. The article suggests testing the theory by seeing whether autistic kids have a natural ability to recognize Neanderthal faces better than human faces.

Monday, April 19, 2010

California seeks to ban public statements

AP reports:
Do gun-toters pose a danger when they carry their weapons in public, even if they're unloaded? ...

"What I'm concerned about is people who have no training can carry a gun for no other purpose than to make a public statement," said the bill's author Democratic Assemblywoman Lori Saldana of San Diego.
So the purpose of her proposed law is to censor that public statement?

The US supreme court says that we have a constitutional right to burn an American flag because flag-burners are making a public statement and because the laws against flag-burning were motivated by suppressing that statement. The same reasoning implies that people should be able to carry an unloaded gun as a public statement.

As the article explains, 32 other states allow people to openly carry loaded guns without any license or permit.

Saturday, April 17, 2010

Why are some people smarter?

NewScientist reports:
Martijn van den Heuvel, a neuroscientist at Utrecht University Medical Center in the Netherlands, found that smarter brains seem to have more efficient networks between neurons - in other words, it takes fewer steps to relay a message between different regions of the brain. That could explain about a third of the variation in a population's IQ, he says.

Another key factor is the insulating fatty sheath encasing neuron fibres, which affects the speed of electrical signals. Paul Thompson at the University of California, Los Angeles, has found a correlation between IQ and the quality of the sheaths (The Journal of Neuroscience, vol 29, p 2212).

We still don't know exactly how much genes contribute to intelligence, with various studies coming up with estimates ranging from 40 to 80 per cent. This wide range of estimates might have arisen because genes contribute more to IQ as we get older, according to a study published last year. By comparing the intelligence of 11,000 pairs of twins, Robert Plomin of King's College London found that at age 9, genes explain 40 per cent of the variation, but by 17 they account for roughly two-thirds (Molecular Psychiatry, DOI: 10.1038/mp.2009.55).
People sometimes mistakenly assume that if a trait is genetic, then it is measurable at an early age.

I mentioned below a study that correlates aggressive behavior in kids aged 3 to 5. It assumed that if a kid has an innate inclination towards aggressive behavior, then such an inclination would not change between 3 and 5. So if the kid became more aggressive, then it must be caused by something that the mom was doing. But it seems likely to me that, like IQ, genes explain a great portion of the variation in aggression as we get older.

Wednesday, April 14, 2010

No benefit to vegetables

CNN reports:
Eating an additional 200 grams a day of fruits and vegetables (about two servings) resulted in only a 3 percent reduction of cancer risk, which was described as "very weak," according to the study published online in the Journal of the National Cancer Institute. ...

Researchers raised the prospect that people who ate more fruits and vegetables could have lower cancer risks because they had generally healthier lifestyles, "such as lower intake of alcohol, never smoking, short duration of tobacco, and higher level of physical activity." These could've been factors rather than just fruit and vegetable intake.

Previous studies have touted the benefits of produce, with findings of 20 to 30 percent reduced cancer rates. The latest finding from the European study was low in comparison.
This is a neglible effect. Most of the supposed health benefits of eating fruits and vegetables are completely bogus.

Monday, April 12, 2010

New bogus spanking study

The pediatricians have a new study on spanking:
According to the study, kids who were spanked often were twice as likely as those who weren't spanked to develop aggressive behaviors such as getting into fights, destroying things or being mean to others. ...

"Causality is extremely difficult to prove," Taylor told Reuters Health. Still, she added, "the evidence is at a point where we want to encourage parents to use techniques other than spanking that can actually lower children's risk for being more aggressive." ...
The study only claims 1.49 times as likely, not twice as likely. I think that it is funny that "aggressive" is used to be synonymous with bad. Aggression is not necessarily bad.
"The evidence is clear that spanking does lead to aggression," psychologist Sandra A. Graham-Bermann, who was not involved in the new study, told Reuters Health in an e-mail. ...

Despite the opinion of professional societies, surveys show that as many as 90 percent of parents spank their children. Taylor encourages parents to talk to a pediatrician about how to better control their toddlers if they use this type of punishment.

"Children need guidance and discipline," said Taylor. "However, parents should focus on positive, non-physical forms of discipline and avoid the use of spanking."
So 90% of parents are doing something wrong? It is much more likely that their study is wrong. They should try to figure out how 90% of parents could be wrong before jumping to conclusions.

Here is the study:
Objective The goal was to examine the association between the use of corporal punishment (CP) against 3-year-old children and subsequent aggressive behavior among those children.

Methods Respondents (N = 2461) participated in the Fragile Families and Child Well-being Study (1998–2005), a population-based, birth cohort study of children born in 20 large US cities. Maternal reports of CP, children's aggressive behaviors at 3 and 5 years of age, and a host of key demographic features and potential confounding factors, including maternal child physical maltreatment, psychological maltreatment, and neglect, intimate partner aggression victimization, stress, depression, substance use, and consideration of abortion, were assessed.
Wow, that is a bizarre list of factors. So they tried to consider whether the parent was spanking the child because of an earlier consideration of abortion? Or whether the child was misbehaving because the dad was beating the mom?

All these factors make the study sound scientific, but ultimately they were just asking the mom whether the child was misbehaving, and asking whether she spanked the child. They found a correlation between misbehavior and spanking, as reported by the mom. This should not be surprising. Presumably the moms said that they spanked as punishment for the misbehavior.

But the study just found a correlation, and cannot determine whether the misbehavior caused the spanking, or the spanking caused the misbehavior. The researchers have chosen to interpret the results as the spanking causing the misbehavior. Such a conclusion might be valid if the misbehavior were predictable from all those other factors, but it is not, of course.

The study concludes:
Conclusions Despite American Academy of Pediatrics recommendations to the contrary, most parents in the United States approve of and have used CP as a form of child discipline. The current findings suggest that even minor forms of CP, such as spanking, increase risk for increased child aggressive behavior. Importantly, these findings cannot be attributed to possible confounding effects of a host of other maternal parenting risk factors.
Note the weasel words. The study definitely does not show that spanking increases aggressive behavior. So they say that the study suggests an increase in risk. By risk, they mean the chance that the study analysis is correct.

The AAP is an anti-spanking organization, and I am surprised that this the best anti-spanking evidence that they can find. As far as I know, there is no proof that any other form of child discipline works better than spanking.

Saturday, April 10, 2010

The Truth about Boys and Girls

A Scientific American Mind article says:
Boys and girls are different, but most psychological sex differences are not especially large. For example, gaps in intellectual performance, empathy and even most types of aggression are generally much narrower than the disparity in adult height, in which the average man is taller than 99 percent of women. ...

Most sex differences start out small -— as mere biases in temperament and play style -— but are amplified as children’s pink- or blue-tinted brains meet our gender-infused culture, including all the tea parties, wrestling matches, playground capers and cafeteria dramas that dominate boys’ or girls’ existence.
The article has some data on male-female differences, but does not really have any evidence that the differences are amplified by culture. It is possible for innate differences to become more significant over time. After all, the height differences increase with age, and that is not from culture.

Tuesday, April 06, 2010

10 kinds of people

You can categorize people based on how they divide up everybody else. For example, psychologists classify people according to the Big Five personality traits, or other systems. Cops tend to divide people into cops, civilians, and scumbags.

Computer scientists divide people according to this:
There are 10 kinds of people. Those who understand binary notation, and those who do not.
In other words, those who get this joke and those who don't.

Some people divide according to religion, right-left politics, IQ, or some other litmus test.

Mathematician T. Tao brilliantly describes how he divides people:
One can broadly divide the outcomes of any given action into three categories: the worst-case scenario, the average-case scenario, and the best-case scenario. ... One can roughly subdivide different modes of thinking by what upper bounds and lower bounds one chooses to set: ...
Some of these distinctions might be incomprehensible to those who do not make them.

The previous post can be understood as Friedman advocating an advantage to one of Tao's types, altho Friedman doesn't suggest actually doing anything to separate those types.

Monday, April 05, 2010

Attracting creative risk-takers

NY Times columnist Thomas L. Friedman :
If we want to bring down unemployment in a sustainable way, neither rescuing General Motors nor funding more road construction will do it. We need to create a big bushel of new companies — fast. … Good-paying jobs don’t come from bailouts. They come from startups. And where do startups come from? They come from smart, creative, inspired risk-takers. How do we get more of those? There are only two ways: Grow more by improving our schools or import more by recruiting talented immigrants. Surely, we need to do both, and we need to start by breaking the deadlock in Congress over immigration, so we can develop a much more strategic approach to attracting more of the world’s creative risk-takers.

... Think Sergey Brin, the Russian-born co-founder of Google, or Vinod Khosla, the India-born co-founder of Sun Microsystems. ...

Right now we have thousands of foreign students in America and 1 million engineers, scientists and other highly skilled workers here on H-1B temporary visas, which require them to return home when the visas expire. That's nuts.
His examples did not have H-1B visas, of course. Brin came here as a small child, and Khosla was just an investor in Sun, not a founder. The whole purpose of the H-1B program is to get cheap foreign labor that will be tied to a particular company. Those workers are prohibited from starting their own companies.

Google and Sun were famously successful, but only in rapidly growing markets that included many other American start-up companies with similar technologies.

We have a racist immigration policy that favors unskilled workers from Mexico and other countries. We get millions of legal immigrants and illegal aliens that way.

Sunday, April 04, 2010

The insult apology

The NY Times (or Int. Herald Tribune) has avery strange apology. You may know the non-apology apology, which pretends to apologize, but only expresses regret that anyone was offended. This Times apology is the insult apology. It pretends to apologize, but really repeats and emphasizes the insult for anyone who may have missed it the first time. It essentially says:
We made a deal with Lee not to call him a crook, but we broke that deal. So we are now saying that we did not intend the reader to infer that Lee is a crook, and we apologize to Lee for the distress of being labeled a crook.
This apology is much more insulting than saying nothing, because it suggests that the paper accidentally told the truth that Lee is a crook, in spite of some underhanded deal to cover up the truth. Perhaps the newspaper was only allowed to operate in Singapore if it was sufficiently respectful of the govt.

I had no idea that it was respectable to use such a brazenly insulting apology. I think that I will try it out myself.

I want to apologize for blog comments that some readers may construed to say that the new Apple iPad is a useless piece of junk. I had promised Steve Jobs that I would not point out the long list of shortcomings to that product, and not explain that it is a useless piece of crap. I wish to state clearly that I was not intending my readers to think that I had broken my promise to Jobs. I apologize to Jobs for any distress or embarrassment caused by any breach of my promise.

Saturday, April 03, 2010

Math textbook errors

The Sacramento California newspaper reports:
Five times three equals five.

Second-graders at 79 Sacramento-area schools can find that equation in their new math books.

Other students using the math series are being asked to count the flies in the playground – only there's no picture of a playground on the page. ...

It's not unusual to find occasional mistakes in textbooks, according to educators. But the errors popping up in the Macmillan/McGraw-Hill series are unusually pervasive: In Folsom Cordova – where some teachers have students looking for the bloopers as a learning exercise – the fourth grade has documented 90 errors in its textbook and related materials, said Assistant Superintendent Janie DeArcos.
It is a scandal that the taxpayers have to buy new math books at all. There are old math books that are much better than the modern ones, and they can be bought cheaply. Maybe the old books don't have DVDs, politically correct messages, and lobbyists vouching for them. But what is more important, learning math or watching an entertaining DVD?

Friday, April 02, 2010

The Male Brain

Psychiatrist Louann Brizendine has a new book on the male human brain, and writes:
The "defend your turf" area -- dorsal premammillary nucleus -- is larger in the male brain and contains special circuits to detect territorial challenges by other males. And his amygdala, the alarm system for threats, fear and danger is also larger in men. These brain differences make men more alert than women to potential turf threats.
I always thought that women were territorial. According to this blog, her statement was based entirely on rat studies that do not apply to humans.

Thursday, April 01, 2010

Mindreading is The Next Big Thing

The NY Times reports:
This layered process of figuring out what someone else is thinking — of mind reading — is both a common literary device and an essential survival skill. Why human beings are equipped with this capacity and what particular brain functions enable them to do it are questions that have occupied primarily cognitive psychologists. ...

Zealous enthusiasm for the politically charged and frequently arcane theories that energized departments in the 1970s, ’80s and early ’90s — Marxism, structuralism, psychoanalysis — has faded. Since then a new generation of scholars have been casting about for The Next Big Thing.

The brain may be it. Getting to the root of people’s fascination with fiction and fantasy, Mr. Gottschall said, is like “mapping wonderland.”

Literature, like other fields including history and political science, has looked to the technology of brain imaging and the principles of evolution to provide empirical evidence for unprovable theories.
I do think that a lot of fiction is particularly appealing to those with mindreading delusions.

It all seems very scientific if the publications show brain scans, even if it is an attempt to prove some unprovable theories.