Matthew Yglesias Falls into a Trap...

Matthew Yglesias writes:

Matthew Yglesias: Horatio Alger's IQ: One thing that always occurs to me when these race/IQ blowups occur is that this issue is kind of in the neighborhood of a different point that doesn't merely recapitulate the race science of yore, does seem to me to have real policy implications, and is really well-supported by the data. This is the fact that IQ test results are meaningfully predictive of various indicators of success in the United States and the main factors that influence how people score on these tests all happen in childhood or earlier (in the fetal environment, in the genes, etc.).

This then becomes one of several available lines of argument that the image of the United States as a magical place where hard work always pays off and the rewards go to those willing to put in the effort is wrong. What's more, the imagine of the United States as a fallen version of that magical place — a country that could become magical if we just improved urban high schools or adopted a better student loan system — is also wrong. Better high schools and better student loan systems are things worth doing on their own terms, but absolutely nothing one can do changes the fact that where people end up is substantially out of their hands...

This seems to me to be substantially wrong. The inheritance of inequality is strikingly large in America today: if the father's lifetime was 100% above the American average for his day, the son's lifetime income will on average be 65% above the American average for his day. That's a lot of inherited inequality. Is this unequal distribution of wealth, income, and status in the United States today the result of the fact that a genetic elite has risen to the top in an IQ-driven meritocracy?

No.

This high degree of inherited inequality isn't because high IQ genetic eliteness genes are being passed down from fathers to sons. As Samuel Bowles and Herbert Gintis (2002), "The Inheritance of Inequality," report:

The direct effect of IQ on earnings... presented in Bowles, Gintis, and Osborne (2002a)... is 0.15, indicating that a [one] standard deviation change in the cognitive score, holding constant... remaining variables... changes... earnings by about one-seventh of a standard deviation.... An estimate of the causal impact of childhood IQ on years of schooling... is 0.53 (Winship and Korenman 1999). A rough estimate of the direct and indirect effect of IQ on earnings... is then... 0.15+(0.53)(0.22) = 0.266....

h is the heritability of IQ.... The value cannot be higher than 1, and most recent estimates are substantially lower, possibly more like a half or less.... [C]ouples tend to be more similar in IQ than would occur by random mate choice.... [The] genetic correlation of parent and offspring [is] (1 + m)/2....

Using the values estimated above, we see that the contribution of genetic inheritance of IQ to the intergenerational transmission of income is (h²(1+m)/2)(0.266)2 = .035(1 + m)h². If the heritability of IQ were 0.5 and the degree of assortation, m, were 0.2 (both reasonable, if only ball park estimates) and the genetic inheritance of IQ were the only mechanism accounting for intergenerational income transmission, then the intergenerational correlation [of lifetime income] would be 0.01, or roughly two percent the observed intergenerational correlation [of lifetime income between parents and children]...

If inherited genetically-based IQ were the source of the extra edge that the children of the rich get in our society, than we would expect a parent with 4 times average lifetime full-time earnings--say $200,000 a year--to have a kid with a lifetime average income of $51,500 instead of the average of $50,000. But it is not $51,500. It is $150,000.

I agree with Matt that "where people end up [in our society] is substantially out of their hands" (although not by any means completely): luck and inheritance of many kinds of things are incredibly important. But this does not mean that equality of opportunity is a mirage. For most of the things that are out of the hands of the individual are not out of our collective hands at all. Genetic influence on IQ is one of the big things that are out of our collective hands--and it turns out it is really not that big a thing at all.

Comments

[Jim]

You might want to ask James Watson about that. Oh, of course, he might now be fearful to give you his honest opinion. You know...chased out of the UK, etc., etc.

[Jim]

You might want to ask James Watson about that. Oh, of course, he might now be fearful to give you his honest opinion. You know...chased out of the UK, etc., etc.

[Jim]

You might want to ask James Watson about that. Oh, of course, he might now be fearful to give you his honest opinion. You know...chased out of the UK, etc., etc.

[bakho]

Matt gets it wrong. Inheritance is important. However, most of the IQ is related to the Inheritance X Environment interaction term and not Inheritance itself. This is why parents of bright children send them to advanced schools and advanced programs, to put the in an environment that maximizes their potential. The best genetic stock could be made into an idiot by being placed in a sterile environment.

[bigTom]

A pretty well stated argument. Beyond inhertited genes, we have nutritional environment, and intellectual environment. The question should arise, how can society positively those variables? Would programs to improve pre-natal, and early childhood nutrition/health be worthwhile? Would pre-school education help? I suspect that a good bit of the variance of the result may already be determined before the child reaches kindergarden. If that is true, then some sort of intervention prior to the child entering public schooling might be a good societal investment.

[whick]

Brad DeLong, I think you misread this.

Yglesias was talking about genetics and environment together as giving some people an inherited advantage. He didn't say that the advantage was mostly genetic, or even largely genetic. The key point in the quoted passage seems to be, "... the main factors that influence how people score on these tests all happen in childhood or earlier (in the fetal environment, in the genes, etc.)". It seems to me that Yglesias mentioned genes only as one factor relevant to inborn advantage, while acknowledging that other factors have their influence during childhood. The point wasn't whether determinants of IQ were genetic or not, it was that they mostly take hold before people reach high school age, so policies that try to remedy inequality at the high school level or later don't have a good chance of wiping out inequality. (Even so, he says, those remedies are still worth something.)

So where did everyone get the idea that Matthew Yglesias was pushing genetics = destiny?

[Brad DeLong]

Touche...

Well, we can change the fetal environment by having barefoot doctors wandering around giving people vitamin, protein, and calcium supplements. We have Head Start. We can do a lot--and would be doing it, if we as a society really cared.

I, by contrast, have to go home to make sure the fourteen-year-old does her practice SAT question this evening.

[mistah charley, ph.d.]

Horatio Alger's name always is taken in vain. I mean, the cause of the social mobility in his novels is not that years of competent hard work are recognized and rewarded - instead, as our friends at Wikipedia put it, "a young boy struggles through hard work to escape poverty. However, it is not the hard work itself that rescues the boy from his fate, but rather a wealthy older gentleman, who admires the boy as a result of some extraordinary act of bravery or honesty that the boy has performed. For example, the boy might rescue a child from an overturned carriage or find and return the man's stolen watch. Often the older man takes the boy into his home as a ward or companion."

Of those who are offering themselves as candidates for President, the ones who have actually risen from a low place in society to a higher one by their own efforts are Kucinich and Edwards, by the way.

[Lemmy Caution]

This adoption study hints that the genetic component of intergenerational earnings transfer is a big deal :

http://www.washingtonmonthly.com/archives/individual/2004_11/005224.php

(even if the IQ portion of that genetic component isn't)

[Lemmy Caution]

This adoption study hints that the genetic component of intergenerational earnings transfer is a big deal :

http://www.washingtonmonthly.com/archives/individual/2004_11/005224.php

(even if the IQ portion of that genetic component isn't)

[wood turtle]

Well, maybe you should consider that the people who knew the answers wrote the tests.

[Steve]

The fallacy here is that correlation isn't the same as effect size. In a complex system with many factors, such as human affairs, a single factor (such as IQ) can have a low correlation with a dependent variable (such as income) but still have a sizable effect (or vice-versa).

The impact of individual IQ on individual income is not high in an absolute sense (although it is high relative to most other potential influences), but if you compare two sizable groups that differ in average IQ but are otherwise similar, the impact of IQ is striking.

Charles Murray quantified this in an ingenious study of pairs of American siblings raised together in non-poor homes. Murray described his findings in the Sunday Times of London in 1997:

"Each pair consists of one sibling with an IQ in the normal range of 90-110, a range that includes 50% of the population. I will call this group the normals. The second sibling in each pair had an IQ either higher than 110, putting him in the top quartile of intelligence (the brights) or lower than 90, putting him in the bottom quartile (the dulls). These constraints produced a sample of 710 pairs. How much difference did IQ make? Earned income is a good place to begin. In 1993, when we took our most recent look at them, members of the sample were aged 28-36. That year, the bright siblings earned almost double the average of the dull: £22,400 compared to £11,800. The normals were in the middle, averaging £16,800." [IQ Will Put You In Your Place, Charles Murray, Sunday Times, UK, Day 25, 1997]

[General Specific]

Steve Sailer said: "The fallacy here is that correlation isn't the same..."

Your entire response is incoherent. It seems as if you've patched together some words that sound like an argument.

Or am I missing something?

BTW: It's clear it's you, since you posted the same response as Steve Sailer to Arnold Kling's "Swindle" post. I would have responded there but they've--once again--banned me from Econlog. The free market of ideas in action.

[General Specific]

You're right. Your patched together words don't even sound like an argument.

My bad.

Thanks for the correction.

[Steve]

All these questions can be studied using the federal government's National Longitudinal Study of Youth that has been following 12,000 people (and their children!) since 1979. They were all given the military's AFQT IQ test in 1980.

The results look much different than Dr. DeLong would wish you to believe. Charles Murray reported in the London Times in 1997 on his study of sibling pairs in the NLSY:

"To make the analysis as unambiguous as possible, I have limited my sample to brothers and sisters whose parents are in the top 75 per cent of American earners, with a family income in 1978 averaging 40,000 (in today's money).

"Families living in poverty, or even close to it, have been excluded. The parents in my sample also stayed together for at least the first seven years of the younger sibling's life.

"Each pair consists of one sibling with an IQ in the normal range of 90-110 ,a range that includes 50% of the population. I will call this group the normals. The second sibling in each pair had an IQ either higher than 110, putting him in the top quartile of intelligence (the bright) or lower than 90, putting him in the bottom quartile (the dull). These constraints produced a sample of 710 pairs.

"How much difference did IQ make? Earned income is a good place to begin. In 1993, when we took our most recent look at them, members of the sample were aged 28-36. That year, the bright siblings earned almost double the average of the dull: 22,400 compared to 11,800. The normals were in the middle, averaging 16,800.

"These differences are sizeable in themselves. They translate into even more drastic differences at the extremes. Suppose we take a salary of 50,000 or more as a sign that someone is an economic success. A bright sibling was six-and-a-half times more likely to have reached that level than one of the dull. Or we may turn to the other extreme, poverty: the dull sibling was five times more likely to fall below the American poverty line than one of the bright.

"Equality of opportunity did not result in anything like equality of outcome. Another poverty statistic should also give egalitarians food for thought: despite being blessed by an abundance of opportunity, 16.3% of the dull siblings were below the poverty line in 1993. This was slightly higher than America's national poverty rate of 15.1%.

"...The young people in our selected sample came from families that were overwhelmingly likely to support college enthusiastically and have the financial means to help. Yet while 56% of the bright obtained university degrees, this was achieved by only 21% of the normals and a minuscule 2% of the dulls. Parents will have been uniformly supportive, but children are not uniformly able.

"The differences among the siblings go far beyond income. Marriage and children offer the most vivid example. Similar proportions of siblings married, whether normal, bright or dull - but the divorce rate was markedly higher among the dull than among the normal or bright, even after taking length of marriage into account. Demographers will find it gloomily interesting that the average age at which women had their first birth was almost four years younger for the dull siblings than for the bright ones, while the number of children born to dull women averaged 1.9, half a child more than for either the normal or the bright.

"Most striking of all were the different illegitimacy rates. Of all the first-born children of the normals, 21% were born out of wedlock , about a third lower than the figure for the United States as a whole, presumably reflecting the advantaged backgrounds from which the sibling sample was drawn. Their bright siblings were much lower still, with less than 10% of their babies born illegitimate. Meanwhile, 45% of the first-born of the dull siblings were born outside of marriage."

[Shay Begorrah]

Oh dear Steve, relying on a political scientist from the AEI for your genetics and social science is never a good idea.

See
http://ezraklein.typepad.com/blog/2007/01/a_charles_murra.html

for a by no means comprehensive list of the ways Murray's work has been debunked.

Wikipedia gives a slightly more charitable view of Murray under its review of "The Bell Curve" but a fair and balanced conclusion would be that there is a much stronger correlation between being a far right wing eugenicist loon and believing Murray's theories than there is between being a scientist with expertise in the area and doing so.

[Robert Scarth]

Hmm - I think there's a lot here that's flawed.

First, Brad says "if the father's lifetime was 100% above the American average for his day, the son's lifetime income will on average be 65% above the American average for his day. That's a lot of inherited inequality"

Income is roughly Pareto distributed - in particular it has a very thick tail ie big extremes (think Bill Gates). These huge extremes pull averages way out. This makes the above quoted fact a bit dubious. I think that the correct thing to do would be to plot quantile of parents' income against quantile of child's income (a "QQ-plot"). That would give a much more useful indication of inequality.

For similar reasons I think that Bowles and Gintis' calculations are bunk.IQ is normally distributed income is Pareto distributed, using correlations as blithely as Bowles and Gintis do is very ill-advised. Again I think it would be better to use rank correlations or QQ plots.

Later, in the comments, Brad says "We can do a lot--and would be doing it, if we as a society really cared".
I believe that this comment is fundamentally mistaken. Society is not a willing purposeful entity - it cannot care.

[General Specific]

"Society is not a willing purposeful entity - it cannot care."

reconsidered becomes:

"Family is not a willing purposeful entity - it cannot care."

Funny how I always hear libertarians tell me that families must be more responsible for this or that.

Maybe libertarians simply don't understand the nature of set theory, in which a collection of entities--individuals--with attributes such as "caring" can have that property ascribed to the entire set, particularly if enough of the entities in that set have that property. One could say that the set has a specified level of "caring" or whatever property you choose.

[General Specific]

Been thinking more about this whole IQ thing. Think of the possibilities: I'm going to bet there are people with a genetic predisposition to alcoholism. Or crime. Or violence. Or moodiness. Or petulance. Etc.

I suggest we start tracking these people. All of them. Everything.

Why educate the future drunkard when he'll just drink himself to death? Why put the petulant and moody students in with the happy students--thus interfering with their happy educational experience.

That's what we need. Separate classrooms. Separate schools. Heck, separate communities. Maybe even separate nations. Someday, when Julian Simon is risen from the dead, separate planets.

All the petulant people--please prepare to ship out to planet petulance.

Something to look forward to: a wonderful human engineered world. Just lovely. A brave new world. Has a nice ring to it, don't you think? Brave new world.

These IQ activists are so precious.

ps: Tomorrow's lesson: Tracking genetic predispositions for future health problems. Part of the brave new health plan.