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Comment by bambax | Hacker News Reader

> How about alcohol?

From the article:

> The lead researcher says he isn't surprised by the findings. "Previous research found for the most part people with high IQs lead a healthy life, but that they are more likely to drink to excess as adults," says James White a psychologist at Cardiff University in the United Kingdom.

What the article doesn't explore is the fact that drugs are expensive; isn't it possible that drug use is correlated with revenue?

The study apparently didn't make a difference between addicts and occasional users.

IQ is also correlated with revenue (probably because that's what it actually measures: socio-economic class), and so that may be a part of the explanation, at least for "recreational" drugs.

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From the ScienceDaily article:"The findings held true, irrespective of anxiety/depression during adolescence, parental social class, and lifetime household income."

"What the article doesn't explore is the fact that drugs are expensive"

Not really. Doing enough drugs to be counted as a 'drug user' shouldn't cost more than five or ten bucks a year.

This is true. From the link:

> Then when participants turned 30, they were asked whether they had used drugs such as marijuana, cocaine and heroin in the past year.

They only need to use drugs once in the last year to qualify.

Exactly. 3.5 grams of weed sells for about $35, and a reasonable recreational dose is about .03 - .05 grams when vaporized, i.e. about 30 to 50 cents per use. You could even use marijuana once per month for less than $5 per year total.

"IQ is also correlated with revenue (probably because that's what it actually measures: socio-economic class)"

False. Charles Murray compared brothers of the same household of different intelligence levels, and found significant disparities in income.

http://www.eugenics.net/papers/murray.html (article originally appeared in The Telegraph)

It's more accurate to say socioeconomic class measures IQ, rather than the other way around. To oversimplify, high IQ people are more productive, IQ at adulthood is heritable to a great extent (~80% of variation in IQ is due to genetic variation), so 1 + 1 = rich families have higher IQ children. Imagine if people were paid based on how tall they are, and replace IQ with height, and it'd be the same -> Tall parents + high heritability for height -> rich families have taller offspring. People don't recognize this with regards to IQ because they ultimately don't believe IQ is highly heritable, which it is.

Links:

IQ and productivity: http://www.onetest.com.au/awms/Upload/documents/whitepapers/...

IQ and heritability: http://en.wikipedia.org/wiki/Heritability_of_IQ (first paragraph)

     they ultimately don't believe IQ is highly 
     heritable, which it is

I don't think anybody sane questions that, but what people are saying and that studies so far have confirmed ...

1) small variations in IQ tests don't matter, like for example the difference between 120 and 140 being negligible and depends a lot on external factors, like rest, vitamins in your blood-stream and mood ... give a person several IQ tests over a period of time and he'll score differently every single time

2) you can increase your IQ score with a certain amount of points just by making your brain work harder. Physical exercises work too (professional athletes are above average)

Ultimately the most common complaint is that intelligence (while hereditary) is not something you can accurately measure and that IQ tests are inherently not reliable.

"give a person several IQ tests over a period of time and he'll score differently every single time"

Not sure what you mean by several. I took 4 (5?) over a 30 year period, and the results were all within a couple percentage points of each other.

I took the same number of tests (4) over a period of 7 years and the minimum I got was 119, while the maximum was 140. Clearly this has some significance, as over 100 you're definitely at least average, over 130 you're definitely gifted, while below 80 you're definitely challenged.

However, my point was that small variations are not significant. Also, the correlation between IQ scores and intelligence in general is highly debatable - and that's what people are arguing about.

Not all IQ tests use the same scoring system. Some use S.D. of 16 others S.D 15 etc.

http://www.paulcooijmans.com/intelligence/sd15.html

Interesting. My variation wasn't that marked. Some of the tests were different, so their scales may have been slightly different (IIRC). On at least one I remember I had when I was umm... 5(?) or 6? then again in mid 20s then again in late 30s - all were within 5 points of each other. I can't remember if it was stanford-binet or something else though. Hrm... no... I think earlier tests were stanford-binet, later were wisc and wj. To that end, the scoring models would have been different on the ones when I was a kid, and I know there's some issues between child scores vs adult scores - not necessarily directly comparable.

> Ultimately the most common complaint is that intelligence (while hereditary) is not something you can accurately measure ...

Individual IQ cannot be precisely measured. However heritability and economics studies show that it can be measured with good accuracy.

http://en.wikipedia.org/wiki/Accuracy_and_precision

A Scottish study found that IQ is stable, over a 66 year period. http://homepages.ed.ac.uk/ijdeary/papers/SMS32_98.pdf

Also, just because one can game the test, or make its result less accurate, it doesn't mean the population level data is much less accurate. I'm reminded of the Body Mass Index - men, by strength training, can put on lots of muscle mass and become classified as "overweight" or even (rarely) "obese" without being fat. But the fact is that most "overweight" men are in fact fat, and not muscular. The fact that a test for an individual can have reduced or zero validity, does not necessarily threaten the validity for the overall population.

If everyone were to start gaming the tests, things might be different. Then again, being able to game the test might be a highly IQ dependent task, so the IQ test remains an IQ test.

it's spectacularly unstable for comparisons between cohorts though, most notably in the case of the Flynn effect. I find it highly unconvincing the average person in the 1930s had the same fundamental level of intelligence as those people scoring 80 on the same tests today.

IQ is heritable, but the catch is that it may, in fact, only be heritable through the mother's half of the genes contributed to the child [1]. The jury is still out on this possibility, but it's being seriously considered in studies right now.

So all those uber-rich guys who select stereotypically dumb, hot trophy wives are doing their offspring no favors in this department. (On the flipside, they may be doing their offspring plenty of favors w/r/t looks, and countless studies have shown that looks are also highly correlated with professional success).

Finally, IQ is, for lack of a better word, malleable. It's not locked in at birth. It can be trained, and it can also wither on the vine if not properly used and challenged. And it's highly susceptible to environment: types of attention received as a child, education, socialization, and even environmental pollutants all play a big role. And they continue to play a big role throughout life, up until roughly the mid-20s, when the brain stops undergoing its rapid changes and loses a lot of its plasticity (though not all of it).

[1] This is something I think science should call the "Lisa Simpson Effect," inasmuch as it explains how a dolt like Homer and a smartie like Marge could produce a genius child.

Could you link to some more info about this? I'm interested.

"IQ is heritable, but the catch is that it may, in fact, only be heritable through the mother's half of the genes contributed to the child [1]."

Do you have a source for this that isn't, um, from the Simpsons? Geneticists have an equation for estimating the response to selection, the change in IQ from parent to offspring, and it uses an average of both parents' IQ. See http://en.wikipedia.org/wiki/Heritability#Response_to_Select... for the equation.

IQ is somewhat more malleable initially, but it seems to converge on a point set by one's genetics, by adulthood. The APA estimated heritability in childhood at .45 and .75 by adulthood.

"Do you have a source for this that isn't, um, from the Simpsons?"

My Simpsons reference was meant to be a colorful analogy, and not a "source." Sheesh.

The source for my statement was journal article I read a few months back. I can't seem to track it down online, but here's a blog that summarizes the studies:

http://flatrock.org.nz/topics/men/thank_mom_for_brains.htm

Like I said, the jury is still out on this. This is a relatively new hypothesis, and not a long-standing theory.

this so called 'new hypothesis' has been around for more than 50 years. It was just not written about because people couldn't accept the consequences have accepting that it was a possibility.

Novel claims require evidence.

Here is another link: http://discovermagazine.com/2005/oct/sex

There are more genes related to intelligence on the X chromosome than on just the X and Y chromosomes. There are still 22 other pairs of chromosomes, which in offspring, are a mishmash of the father and mother's chromosomes. Genes on these chromosomes have been experimentally linked with intelligence (eg, http://genepi.qimr.edu.au/contents/p/staff/CV453.pdf)

Plus, there are sex differences in intelligence; there are more male dullards and geniuses. Men score higher on visuospatial ability, and women on verbal ability. Given that these are distinctly sex related, their genesis lies in differences between the X and Y chromosomes.

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