Saturday, September 27, 2014

Twins reared apart

For those interested in studies of identical twins reared apart, see IQ Similarity of Twins Reared Apart: findings and responses to critics, Bouchard (1997). A question sometimes raised by critics concerns the extent to which twins reared apart actually experienced different environments. Norms of reaction, GxE interactions, and other (conceptually trivial but potentially obfuscatory) topics are also discussed.

Susan Farber wrote a 1981 book that was critical of twin studies. Click below for larger image.

See also Heritability 2.0.

Monday, September 22, 2014

Piketty on Capital

Piketty on EconTalk (podcast) -- a lively discussion between Russ Roberts and guest Thomas Piketty. See earlier post here.
Piketty: ... to summarize very quickly our conclusion, we feel that the theory of marginal productivity is a bit naive, I think for this top part of the labor market. That is to say when a manager manages to get a pay increase from $1 million a year to $10 million a year, according to the textbook based on marginal productivity, this should be due to the fact that his marginal contribution to the output of his company has risen from 1 to 10. Now it seems a bit naive. It could be that in practice individual marginal productivities are very hard to observe and monitor, especially in a large corporation. And there is clearly strong incentives for top managers to try to get as much as they can.

... Now, when the top tax rate is 82%, now of course you always want to be paid $1 million more, but on the margin when you get a pay increase of $1 million, 82% is going to go straight to the Treasury, so your incentive to bargain very aggressively and put the right people in the right compensation committee are going to be not so strong. And also your shareholders, your subordinates, maybe will tend to tell you, look, this is very costly. Whereas when the top tax rate goes down to 20, 30% or even 40%, so you keep 2/3rds or 60% of the extra $1 million for you, then the incentives are very, very different. Now, this model seems to explain part of what we observe in the data. In particular, it's very difficult to see any improvement in the performance of managers who are getting $10 million instead of $1 million. When we put together a data base with all the publicly traded companies in North America, Europe, Japan, trying to compare in the companies that are paying their managers $10 million instead of $1 million, it's very difficult to see in the data any extra performance.

... But let me make clear that I love capital accumulation and I certainly don't want to reduce capital accumulation. The problem is the concentration. So let me make very clear that inequality in itself is of course not a problem. Inequality can actually be useful for growth. Up to a point. The problem is when inequality of wealth and concentration of wealth gets too extreme, it is not useful any more for growth. And it can even become bad, because it leads to high perpetuation of inequality over time, so it can reduce social mobility. And it can also be bad for the working or for the democratic institutions. So where is the tipping point--when is it that inequality becomes excessive? Well, I'm sorry to tell you that I don't have a formula for that.

... In the United States right now, the bottom 50% of the population own about 2% of national wealth. And the next 40% own about 20, 22% of national wealth. And this group, the middle 40%, the people who are not in the bottom 50% and who are not in the top 10%, they used to own 25-30% of national wealth. And this has been going down in recent decades, as shown by a recent study by Saez and Zucman and now is closer to 20, 22%. Now, how much should it be? I don't know. I don't know. But the view that we need the middle class share to go down and down and down and that this is not a problem as long as you have positive growth, I think is excessive. You know, I think, of course we need entrepreneurs. I'm not saying, look, if it was perfect equality the bottom 50% should own 50% and the next 40% should own 40. I am not saying that we should have this at all. I'm just saying that when you have 2% for the bottom 50 and 22 for the next 40, you know, the view that we cannot do better than that [[ because ]] you won't have entrepreneurs any more, you won't have growth any more, is very ideological.

... I am actually a lot more optimistic than what some people seem to believe. I'm very sorry some people feel depressed after they read my book because after all this is not the way I wrote it. In fact, I think there are lots of reasons to be optimistic. For instance, one good news coming from the book is that we've never been as rich in terms of net wealth than we are today in developed countries. And we talk all the time about our public debt, but in fact our private wealth as a fraction of GDP has increased a lot more than our public debt as a fraction of GDP, so our national wealth, the sum of private and public wealth, is actually higher than it has ever been. So our countries are rich. It is our governments that are poor, which is a problem; but it raises issues of organization and institution but that can be addressed.

Ivy admissions discussed by parents of gifted kids

At this link you can find pages of discussion about Ivy admissions, stimulated at least in part by Pinker's recent article (see here and here), among parents of highly gifted children. Most of the discussants realize that there is a lot of room in the tail beyond the SAT ceiling. (Hint: parents of gifted kids tend to be fairly sharp themselves ... I wonder why? ;-)

I am not one of the commenters on the thread. Bonus points if you click the link above and read through to the Bezos quote ;-)
I suspect the 10 percent comment means something along the lines of 10 percent have been Intel semifinalists, have published significant research, qualified for USAMO, etc. That doesn't mean that the other 90 percent are dumb jocks and clueless legacies. The 90 percent probably includes some very bright, gifted kids, but they haven't cured cancer (not yet at least).
It means that 5%-10% are selected on academic merit alone. The rest are selected on a combination of factors. They may (mostly) have quite high academic merit, but other factors are considered, and so the overall academic merit of the class, though high, is less than it would have been if academic merit played a larger role in admissions. Students are admitted who are less academically meritorious than some who are rejected.


Regardless of what colleges supposedly should do, and what they do do, there is still the inescapable fact that SAT/ACT test have too low a ceiling, and the colleges are missing a huge amount of information about the academic ability of their applicants, and there is no excuse for them not actively pushing for harder tests.


They have a very good reason for refusing harder tests--it restricts their freedom. The first goal for colleges are self preservation and growth, hence the preference for legacies and athletics, both of which fuel alumni donations. But once self-preservation and growth has been achieved, college believe themselves to be forces for social engineering, helping right what they see as wrong in society.


Maybe it isn't about a harder test. Let's say that current perfect scores get you a group at a top school with IQs of 135+. Maybe it is 140+. With a different test, do you get 150+. But do you get a group that you want? Do they have the social skills to have a good mix, good clubs? There are factors that you want to have a certain type of school whether you are Harvard or Penn State. Harvard doesn't want a whole school that could pursue graduate work in Physics. They want fencing teams and rowing and a football team to play Yale. So for those of you wishing for a harder test, what does that mean to the student body, the college experience if you don't take into account all the other things. Because how much does it change if your roommate has an IQ of 175 in math, but 125 in ELA or 145 overall? I can see MIT wanting the 175 in math but Ivy's? Do you really want your kid going to a school where they just sit and have deep discussions about theories with other students?


But that assumes that those people are only interested in their peculiar "pointy" things. And that PG people lack social skills. Which is where my A versus B archetypes came from to begin with. Assume that they are BOTH HG+.

HG+ people come in a lot of different varieties there.

Just because someone has a FSIQ of 150+ doesn't mean that s/he is necessarily passionate about particle physics. It might mean that s/he is capable of learning it, but even that probably depends on the individual.

[[ IIUC, PG = Profoundly Gifted ; HG = Highly Gifted ]]

Do you really want your kid going to a school where they just sit and have deep discussions about theories with other students?
Where they just talk about big ideas? No. But I suspect that no one talks about nothing but big ideas, so the question is exaggerated.

As for a place where talking about big ideas is a normal part of the culture, yes, absolutely. Isn't that supposed to be the point about being at a place that calls itself a top-tier university --- that the people there are very bright and interested in big ideas in science, philosophy, history, and so on?

Saturday, September 20, 2014

How to build the future

I just bought 10 copies for my team at MSU. More here. The book is based on Thiel's Stanford class CS 183: Startup -- see course notes.

Earlier posts on Thiel.

Thursday, September 18, 2014

Excellent Sheep and Chinese Americans

Two recent podcasts I recommend. I disagree with Deresiewicz on many points (see my comments on Steve Pinker's response here and here), but the discussion is worth a listen.
Do the Best Colleges Produce the Worst Students?

As schools shift focus from the humanities to "practical" subjects like economics and computer science, students are losing the ability to think in innovative ways, argues William Deresiewicz. When he was a professor at Yale he noticed that his students, some of the nation’s brightest minds, seemed to be adrift when it came to knowing how to think critically and creatively and how to find a sense of purpose in life. Deresiewicz explains why he thinks college should be a time for self-discovery, when students can establish their own values and measures of success, so they can forge their own path. His book Excellent Sheep : The Miseducation of the American Elite and the Way to a Meaningful Life addresses parents, students, educators, and anyone who's interested in the direction of American society, exposing where the system is broken and presenting solutions.

Chinese Americans and the American Dream

In many ways, Chinese Americans today are exemplars of the American Dream—moving from indentured servitude to second-class status and outright exclusion to economic to social integration and achievement. But this narrative leaves a lot out. Eric Liu, author, educator, and entrepreneur, pieces together a sense of the Chinese American identity and looks at what it means to be Chinese American in this moment. His new book A Chinaman's Chance: One Family's Journey and the Chinese American Dream is a collection of personal essays that range from the meaning of Confucius to the role of Chinese Americans in shaping how we read the Constitution to why he hates the hyphen in "Chinese-American."

Sunday, September 14, 2014

Harvard admissions and meritocracy

Motivated by Steve Pinker's recent article The Trouble With Harvard (see my comments here), Ephblog drills down on Harvard admissions. The question is just how far Harvard deviates from Pinker's ideal of selecting the entire class based on intellectual ability. Others raised similar questions, as evidenced by, e.g., the very first comment that appeared on The New Republic's site:
JakeH 10 days ago

Great article. One quibble: Pinker says, based on "common knowledge," that only ten (or five) percent of Harvard students are selected based on academic merit, and that the rest are selected "holistically." His implication is that "holistic" consideration excludes academic merit as a major factor. But that's surely not the case. Even if Harvard only selects ten percent of its students based on academic factors alone, it seems likely that academic and test score standards are high for the remaining 90 percent. We don't have enough information on this point, because, I suppose, it's not available. (To solve that problem, I join Pinker's call for a more transparent admissions process.)
I don't know exactly how Harvard admissions works -- there are all sorts of mysteries. But let me offer the following observations.

1. Pinker claimed that only 5-10 percent of the class is admitted purely on the basis of academic merit (see more below). The 5-10 percent number was widely reported in the past, including by scholar Jerome Karabel. No one knows what Harvard is up to at the moment and it's possible that, given the high demand for elite education, they have increased their academic focus over the years.

2. IIRC, the current SAT ceiling of 1600 (M+CR) corresponds to about 1 in 1000 ability (someone please tell me if I am mistaken). So there are at least a couple thousand US kids per cohort at this ability level, and several times more who are near it ("within the noise"). A good admissions committee would look at other higher ceiling measures of ability (e.g., performance in math and science competitions) to rank order top applicants. The 800 ceiling on the math is not impressive at all -- a kid who is significantly below this level has almost no chance of mastering the Caltech required curriculum (hence even the 25th percentile math SAT score at Caltech is 770; in my day the attrition rate at Caltech was pretty high -- a lot of people "flamed out"). The reduced SAT ceiling makes it easier for Harvard to hide what it is up to.

4. My guess is that Harvard still has a category, in the past called S ("Scholar"; traditionally 5-10 percent of the class, but perhaps larger now), for the top rank-ordered candidates in academic ability alone. Most of the near-perfect scorers on the SAT will not qualify for S -- it is more impressive to have been a finalist in the Intel science competition, written some widely used/acclaimed code, made (or nearly made) the US IMO or IPhO teams, published some novel research or writing, etc. Harvard sometimes boasts about the number of perfect SAT scorers it rejects each year, so clearly one can't conclude that a 1600 on CR+M alone qualifies for the S category. Along these lines, one even reads occasional stories about Harvard rejecting IMO participants.

5. In remaining categories Harvard almost certainly uses a more holistic approach that also weights athletics, extracurriculars, etc. Some of the people who score high on this weighted measure might not have qualified in S, but nevertheless are near the ceiling in SAT score. It has been reported in the past that Harvard used a 1-5 scoring system in academics, sports, leadership, music, etc. and that to have serious consideration (outside the S category, which is for real superstars), one needed to have two or more "1" scores -- e.g., valedictorian/high SATs + state-level tennis player + ...

From the comments above, it should be clear that one can't simply use the percentage of near-perfect SAT scorers in the class to determine the size of the S category.

See here for discussion of meritocratic test-based systems in other countries. For instance, the Indian IIT, the French Ecole Normale Superieure, and the Taiwan university entrance exams, have in the past explicitly ranked the top scorers each year. (The tests are hard enough that typically no one gets near a perfect score; note things may have changed recently.) I know more than a few theoretical physicists who scored in the top 5 in their entire country on these exams. Mandlebrot writes in his autobiography about receiving the highest ENS score in France.

Friday, September 12, 2014

Embrace the Grind

Talent, hard work, and success in jiujitsu. "Show up every day and keep pushing through."

Wednesday, September 10, 2014

What is best for Harvard

I highly recommend Steve Pinker's The Trouble With Harvard in The New Republic.
... Like many observers of American universities, I used to believe the following story. Once upon a time Harvard was a finishing school for the plutocracy, where preppies and Kennedy scions earned gentleman’s Cs while playing football, singing in choral groups, and male-bonding at final clubs, while the blackballed Jews at CCNY founded left-wing magazines and slogged away in labs that prepared them for their Nobel prizes in science. Then came Sputnik, the '60s, and the decline of genteel racism and anti-Semitism, and Harvard had to retool itself as a meritocracy, whose best-and-brightest gifts to America would include recombinant DNA, Wall Street quants, The Simpsons, Facebook, and the masthead of The New Republic.

This story has a grain of truth in it: Hoxby has documented that the academic standards for admission to elite universities have risen over the decades. But entrenched cultures die hard, and the ghost of Oliver Barrett IV still haunts every segment of the Harvard pipeline.

At the admissions end, it’s common knowledge that Harvard selects at most 10 percent (some say 5 percent) of its students on the basis of academic merit. At an orientation session for new faculty, we were told that Harvard “wants to train the future leaders of the world, not the future academics of the world,” and that “We want to read about our student in Newsweek 20 years hence” (prompting the woman next to me to mutter, “Like the Unabomer”). The rest are selected “holistically,” based also on participation in athletics, the arts, charity, activism, travel, and, we inferred (Not in front of the children!), race, donations, and legacy status (since anything can be hidden behind the holistic fig leaf).

The lucky students who squeeze through this murky bottleneck find themselves in an institution that is single-mindedly and expensively dedicated to the pursuit of knowledge. It has an astonishing library system that pays through the nose for rare manuscripts, obscure tomes, and extortionately priced journals; exotic laboratories at the frontiers of neuroscience, regenerative medicine, cosmology, and other thrilling pursuits; and a professoriate with erudition in an astonishing range of topics, including many celebrity teachers and academic rock stars. The benefits of matching this intellectual empyrean with the world’s smartest students are obvious. So why should an ability to play the bassoon or chuck a lacrosse ball be given any weight in the selection process?

The answer, ironically enough, makes the admissocrats and Deresiewicz strange bedfellows: the fear of selecting a class of zombies, sheep, and grinds. But as with much in the Ivies’ admission policies, little thought has given to the consequences of acting on this assumption. Jerome Karabel has unearthed a damning paper trail showing that in the first half of the twentieth century, holistic admissions were explicitly engineered to cap the number of Jewish students. Ron Unz, in an exposé even more scathing than Deresiewicz’s, has assembled impressive circumstantial evidence that the same thing is happening today with Asians.

Just as troublingly, why are elite universities, of all institutions, perpetuating the destructive stereotype that smart people are one-dimensional dweebs? It would be an occasion for hilarity if anyone suggested that Harvard pick its graduate students, faculty, or president for their prowess in athletics or music, yet these people are certainly no shallower than our undergraduates. In any case, the stereotype is provably false. Camilla Benbow and David Lubinski have tracked a large sample of precocious teenagers identified solely by high performance on the SAT, and found that when they grew up, they not only excelled in academia, technology, medicine, and business, but won outsize recognition for their novels, plays, poems, paintings, sculptures, and productions in dance, music, and theater. A comparison to a Harvard freshman class would be like a match between the Harlem Globetrotters and the Washington Generals.
Pinker's position is similar to that of some of his distinguished predecessors on the Harvard faculty (see below). The ideal school Pinker is describing is called "Caltech" :-)
Defining Merit:
[The Chosen, Jerome Karabel] ... In a pair of letters that constituted something of a manifesto for the wing of the faculty favoring strict academic meritocracy, Wilson explicitly advocated admitting fewer private school students and commuters, eliminating all preferences for athletes, and (if funds permitted) selecting "the entering class regardless of financial need on the basis of pure merit." The issue of athletes particularly vexed Wilson, who stated flatly: "I would certainly rule out athletic ability as a criterion for admission of any sort," adding that "it bears a zero relationship to the performance later in life that we are trying to predict." He also argued that "it may well be that objective test scores are our only safeguards against an excessive number of athletes only, rich playboys, smooth characters who make a good impression in interviews, etc." As a parting shot, Wilson could not resist accusing Ford of anti-intellectualism; citing Ford's desire to change Harvard's image, Wilson asked bluntly: "What's wrong with Harvard being regarded as an egghead college? Isn't it right that a country the size of the United States should be able to afford one university in which intellectual achievement is the most important consideration?"
E. Bright Wilson was professor of chemistry and member of the National Academy of Sciences, later a recipient of the National Medal of Science. The last quote from Wilson could easily have come from anyone who went to Caltech! Indeed, both E. Bright Wilson and his son, Nobel Laureate Ken Wilson (theoretical physics), earned their doctorates at Caltech (the father under Linus Pauling, the son under Murray Gell-Mann). ...
Some have quibbled with Pinker's assertion that only 5 or 10% of the Harvard class is chosen with academic merit as the sole criterion. They note the overall high scores of Harvard students as evidence against this claim. But a simple calculation makes it obvious that the top 2000 or so high school seniors (including international students, who would eagerly attend Harvard if given the opportunity), ranked by brainpower alone, would be much stronger intellectually than the typical student admitted to Harvard today. (Vanderbilt researchers David Lubinski and Camilla Benbow, mentioned above by Pinker, study a population that is roughly 1 in 10k in ability. About two hundred US high school seniors with this level of talent are available each year; adding in international students increases the total significantly.)
Defining Merit: ... Bender also had a startlingly accurate sense of how many truly intellectually outstanding students were available in the national pool. He doubted whether more than 100-200 candidates of truly exceptional promise would be available for each year's class. This number corresponds to (roughly) +4 SD in mental ability. Long after Bender resigned, Harvard still reserved only 10 percent of its places (roughly 150 spots) for "top brains". (See category "S" listed at bottom.) ...

Typology used for all applicants, at least as late as 1988:

1. S First-rate scholar in Harvard departmental terms.
In the end, however, I have to agree with old Wilbur Bender, the Harvard admissions dean who fought off idealistic faculty committees in the the 1950s. A Harvard that followed Pinker's advice would, after a generation or two, be reduced in status, prestige, and endowment size, to a mere Caltech or Ecole Normale Superieure. (Both schools, by some estimates, produce Nobel Prize winning alumni at a rate several times higher than Harvard.)

What is good for our nation, and for civilization as a whole, is not what is best for Harvard.

Monday, September 08, 2014

Common genetic variants associated with cognitive performance

This is a follow up to earlier papers by the SSGAC collaboration -- see First GWAS Hits For Cognitive Ability and SNPs and SATS. Effect sizes found are typically ~ 0.3 IQ points. Someone with 50 more good variants (similar to these) than the average person would be about 1 SD above average in IQ.

Note among the authors names like Pinker, Visscher, Plomin, McGue, Deary, etc. Thank god it wasn't the sinister Chinese who got there first! For more on this topic, including the status of the BGI study, see Genetic Architecture of Intelligence (arXiv:1408.3421).
Common genetic variants associated with cognitive performance identified using the proxy-phenotype method (PNAS, doi: 10.1073/pnas.1404623111)

We identify common genetic variants associated with cognitive performance using a two-stage approach, which we call the proxy-phenotype method. First, we conduct a genome-wide association study of educational attainment in a large sample (n = 106,736), which produces a set of 69 education-associated SNPs. Second, using independent samples (n = 24,189), we measure the association of these education-associated SNPs with cognitive performance. Three SNPs (rs1487441, rs7923609, and rs2721173) are significantly associated with cognitive performance after correction for multiple hypothesis testing. In an independent sample of older Americans (n = 8,652), we also show that a polygenic score derived from the education-associated SNPs is associated with memory and absence of dementia. Convergent evidence from a set of bioinformatics analyses implicates four specific genes (KNCMA1, NRXN1, POU2F3, and SCRT). All of these genes are associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory.

Saturday, September 06, 2014

GameDay: Spartans vs Ducks

The Spartans hung in there (amazing that they were leading at the half) but ultimately the Ducks were too much.

I started out in the Spartan section but I went up to the Oregon President's box at halftime.

My t-shirt says "Spartan For Life" -- didn't go over very well with the Oregon fans! I took abuse everywhere except in the elitist box.

This is very Eugene: a human traffic jam crossing the footbridge over the Willamette river.

Friday, September 05, 2014

Back in Eugene

New UO science building:

Setting up for ESPN College GameDay:

Across the river to the stadium:

Ducks and Spartans play tomorrow:

I'm wrestling with divided loyalties. I've been a big Marcus Mariota fan since he came to UO, and I'd like to see him win a Heisman and a national title.

Craft brewing mecca:

@ Amazon

I was at the Amazon campus in Seattle yesterday to give a talk. Unbelievable construction and development in this part of town.

This is the famous Bezos "door desk" :-)

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