about me
game theory
... more
Subscribe Weblog



Taken from Paul Watzlawick's book How Real is Real?[1]:

Professor Alex Bavelas, a noted expert in small-group interaction, has shown in several experiments that [misinformation] has a powerful influence on a human being's sense of reality.

In one experiment, two subjects, A and B, are seated facing a projection screen. There is a partition between them so that they cannot see each other, and they are requested not to communicate. They are then shown medical slides of healthy and sick cells and told that they must learn to recognize which is which by trial and error. In front of each of them are two buttons marked "Healthy" and "Sick," respectively, and two signal lights marked "Right" and "Wrong." Every time a slide is projected they have to press one of the buttons, whereupon one of the two signal lights flashes on.

"A" gets true feedback; that is, the lights tell him whether his guess was indeed right or wrong. His situation is one of simple discrimination, and in the course of the experiment, most "A" subjects learn to distinguish healthy from sick cells with a fair degree of correctness (i.e., about 80 percent of the time).

"B's" situation is different.
His feedback is based not on his own guesses, but on A's. Therefore it does not matter what he decides about a particular slide; he is told "right" if "A" guessed right, "wrong" if "A" guessed wrong. B does not know this; he has been led to believe there is an order, that he has to discover this order, and that he can do so by making guesses and finding out if he is right or wrong. But as he asks the "sphinx" he gets very confusing answers because he does not know that the sphinx is not talking to HIM.

In other words, there is no way in which he can discover that the answers he gets are noncontingent -- that is, have NOTHING to do with his questions -- and that therefore he is not learning anything about his guesses. So he is searching for an ORDER where there is none that HE could discover.

A and B are eventually asked to discuss what they have come to consider the rules for distinguishing between healthy and sick cells. "A"'s explanations are simple and concrete; "B"'s are of necessity subtle and complex -- after all, he had to form his hypothesis on the basis of very tenuous and contradictory hunches.

The amazing thing is that A does not simply shrug off B's explanations as unnecessarily complicated or even absurd, but is impressed by their sophisticated "brilliance." "A" tends to feel inferior and vulnerable because of the pedestrian simplicity of his assumption, and the more complicated "B"'s "delusions", the more likely they are to convince A. <>

Before they take a second, identical test (but with new slides), A and B are asked to guess who will now do better than in his first test. All B's and most A's say that B will.

[1] Watzlawick, Paul: Wie wirklich ist die Wirklichkeit? Wahn, Täuschung, Verstehen. Piper, 4. Auflage Mai 2006, S. 61 ff.

I stumbled across a blog written by a "40-year old hedge fund manager" called Spartacus, which is kind of spooky because I'm a 40-year old hedge fund manager who occasionally blogs. Even more fun, the findings of the Bell Curve continue to resonate, especially with economists. It seems Charles Murray wrote a new defence of his original position entitled The Inequality Taboo. Not many subjects create as much name calling as this subject, which I find instructive because no one gets mad when you say something wrong like 2+2=5.

Anyway, Brad Delong's critique of Murray's latest makes mention of this note by Bowles and Gintis:
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 [of] the observed intergenerational correlation [of lifetime income between parents and children].
That's curious. The link provides some more data behind those back-of-the-envelope calculations, but it seems low from my own experience (2%?), and contrary to this study Murray did when he addressed many issues about the correlation between IQ and income in this brief article.

First Murray defines these IQ segments: Very Dull <75, Dull 75-89,
Normal 90-109, Bright 110-124, Very Bright 125+. Then he notes:
The National Longitudinal Study of Youth (NLSY), included in its sample 5,863 subjects who shared the same household with at least one other NLSY subject as brother or sister, thereby enabling researchers to replicate The Bell Curve's analyses without worrying about the ambiguities that arise when different data bases are being compared.

To qualify for the sibling sample I use here, both siblings had to have a valid score on the Armed Forces Qualification Test (AFQT) administered in 1980. To make matching for background as unambiguous as possible, I further limited the sample to pairs of subjects who were full biological siblings and who lived in the same home with both biological parents through at least the younger sibling's seventh year.
In 1992, the median earnings for the Normals was $20,000. Their Very Bright siblings were already averaging $33,500 while their Very Dull siblings were making only $7,500. Once again, the Brights and Dulls each fell about halfway between ($26,500 and $14,000 respectively).
Thus he documents considerable correlation between IQ and income independent of SES. I find this hard to reconcile with the Bowles and Gintis estimation of 2% that DeLong finds so convincing. Of course, I remember Bowles mostly for his vigorous championing of East German productivity from state-sponsored production plans in the months prior to the wall falling in 1989.

Scientific American: A study ($) of Chinese and American students has found that the two groups looked at scenes in photographs in distinct ways. The findings indicate that previously observed cultural differences in judgment and memory between East Asians and North Americans derive from differences in what they actually see. There is a growing body of evidence to suggest that whereas North Americans tend to be more analytic when evaluating a scenario, fixating on the focal object, East Asians are generally more holistic, giving more consideration to the context. Researchers have not known, however, whether these differences originate during the encoding, retrieval, or mental comparison stages of perceptual-cognitive processing, or whether they might even be the result of reporting bias.

To try to pinpoint when these differences emerge, Richard E. Nisbett of the University of Michigan and his colleagues conducted a series of experiments in which Chinese and American students were shown a number of images, each depicting a single subject against a realistic and complex background. The participants--who wore an eye-movement tracker during the tests--were then shown pictures containing the same subjects on either old or new backgrounds and asked to judge whether they had seen the subjects before.

percept01As the team predicted, the American students homed in on the focal subject sooner and longer than did the Chinese students, who paid more attention to the background imagery. This suggests that the Americans encoded more visual details for the focal objects than did the Chinese, which would explain why the Americans fared better when it came to determining whether they had seen a given subject before, even when it was presented against a new backdrop.

Nisbett and his collaborators posit that these differences in attention to object and context arise through socialization practices. "East Asians live in relatively complex social networks with prescribed role relations. Attention to context is, therefore, important for effective functioning," the scientists observe. "In contrast, Westerners live in less constraining social worlds that stress independence and allow them to pay less attention to context. [Source]

percept02Proportion of fixations to object or background, across the 3-s time course of a trial. Data points are sampled every 10 ms for 0–1,500 ms, and every 50 ms for 1,500–3,000 ms, averaging over all 36 trials. The sum of percentages at each time point may not total 100% because, at times, participants were in the process of making a saccade, thus they were in between fixations. The graph illustrates distinct eye tracking patterns of Americans and Chinese during the 3-s period. Cultural differences begin by 420 ms after onset, when an interaction of culture and region was observed, with the Chinese, but not the Americans continuing to fixate the background more than the focal object. Averaging the data from 420 to 1,100 ms, Americans were fixating focal objects at a greater proportion than backgrounds, compared with Chinese. Averaging the data from 1,100 to 3,000 ms, Chinese were fixating more often to the backgrounds and less to the objects, compared with Americans.

drinkI have long considered anthropology a crock. Instead of analyzing human biodiversity objectively in its richness, it's infused with political correctness, tendentious descriptions of mores and customs without any theory other that all humans are identical except for the current distribution of resources. For example, witness the Seville Statement on Violence where anthropologists proclaimed it scientifically proven that war, violence, and agression are not natural to humans. Kumbaya.

But maybe I'm too harsh. The nice thing about a field of study built on good intentions is that it can be very fun if you do it right. For example, Dartmouth professor Hoyt Alverson studied "the drinking culture in college." A recent article in the Dartmouth newspaper notes this deep insight into bing drinking:
Beer pong and similar drinking games are not played solely to achieve inebriation, Alverson finds, but instead serve as a competitive outlet for high-achieving students, and a structured atmosphere for peer interaction.
I hope professor Alverson was smirking when he wrote this gem:
there is an apprehension about aloneness which is ameliorated by the plans and structures of ritual drinking

Many Eurovision viewers believe there are a several ‘cliques’ in the contest in which a number of countries all vote in a similar way. Using a framework of complex networks researchers from the University of Oxford analysed voting behaviour in the contest over a period from 1992 to 2003.

'As a measure of each country’s actions, we form a data series consisting of the average number of points assigned to each other entrant in the years in which they both compete. The closeness of each pair of countries can then be measured by comparing these data series using Pearson’s correlation coefficient (ρ). <> The Pearson coefficients are then rescaled to produce a ‘distance’ between 0 and 2 using the relationship that the rescaled distance is equal to Sqrt(2(1 − ρ)). The most closely related countries have rescaled distances close to 0, while the least correlated countries have distances close to 2. This data is then used to plot a dendrogram which provides a visual aid for identifying clusters.dendrogram_songcontestThe figure above shows the resulting dendrogram obtained by consecutively linking the most correlated countries. For example, Greece and Cyprus have the smallest rescaled separation and so they are combined first. The next smallest rescaled distance is between Denmark and Sweden and so they form the next cluster. Once two countries A and B have been combined into a cluster, they are considered to be at the same distance from another country C, which is equal to the shorter of the distances AC and BC. This construction is then generalized up for clusters with more than two countries. The distance between any two clusters is the shortest distance between any two countries in the two clusters. Progressively more countries and clusters are combined in this way, with some countries combining with existing clusters, until all the countries are united into a single cluster. The dendrogram shows quite explicitly that the voting patterns of certain countries are highly correlated. Greece and Cyprus have a very small rescaled distance which demonstrates a very strong voting correlation. This particular finding thereby confirms a long-held belief among regular Eurovision viewers. There is a slightly less correlated cluster that involves the Nordic countries, Denmark, Sweden, Iceland, Norway, Finland, and somewhat surprisingly, Estonia. Many other clusters also arise: Bosnia and Turkey, Croatia and Malta, UK and Ireland (who also show a correlation with the Nordic clique), Belgium and the Netherlands and France and Portugal. The high correlations between the way in which countries assign points provides evidence in support of the theory that voting groups exist'[1].

Further analysis of voting patterns between countries allowed the researchers to identify several countries that appear to be more ‘in tune’ with the rest of Europe, that is, countries that are compatible with a greater number of countries than others. Compatibility between countries was measured by analysing how often a given country exchanged points with another country. If this number exceeded that expected for a ‘random contest’, the countries were judged to be compatible. The country that was found to be compatible with the greatest number of other countries was the UK, whilst at the opposite end of the spectrum France, and to a lesser degree, Spain, were found to be the least compatible with the rest of Europe. |University of Oxford News|

via Daily Favorite

[1] How does Europe Make Its Mind Up [pdf], Daniel Fenn et al.

rosesWhen we seek a partner in everyday life, we tend to gravitate toward people who are similar to us. But when we seek a romantic liaison online, we become much less selective and feel more free to investigate different types of people — people we would usually not consider. Our virtual selves are much more daring and open, thanks to anonymity. That's the word from a team of researchers at Stockholm University in Sweden... continue reading.

albionseedI just finished a fabulous book that I can’t recommend highly enough, Albion’s Seed by David Hackett-Fischer. It was published in 1989, and I truly regret not having read 15 years ago. It really gives one a good feel for where America came from, four distinct groups of Englishmen. Surely it doesn’t apply well to current America, where not only is English now a minor ancestry, but most people are a mix, and the community elders have long lost their monopoly on ethics. Yet it really helps understand history. The US Constitution, or the Civil War, or even figures like George Washington, make much more sense with an understanding the four major folkways of early America.

The four sects are:

Puritans: This bourgeois, intellectual and moralistic bunch largely originated in Eastern England. From 1629 to 1640, they settled New England, (Massachusetts, Connecticut, Maine, etc) Archetypes would be Cotton Mather (of Salem witch trial fame), or John Adams.

Cavaliers: aristocrats and their indentured servants from class-ridden Southern England moved to the lowland South (Carolinas and Virginia) from 1642-1675. George Washington and Robert E Lee illustrate the South's gentlemanly and aristocratic ways.

Quakers: Calm and business-like (think Ben Franklin) and others from the North Midlands of England and Wales settled Pennsylvania and the rest of the Delaware Valley in 1675-1725. They invited German Mennonites and others of compatible habits to join them. Pennsylvanians spread out across the Middle West

Scots-Irish: Finally, the belligerent folks from the violent Scottish-English border region came to the Appalachian backcountry from 1718 to 1775. Their descendents spread west across the upper South. The prototype: Andy Jackson or Daniel Boone. They're typically called "Scots-Irish," although they were culturally quite different from Scottish Highlanders or Irish Catholics.

One factoid. Prior to 1856 every President but one came from a single cultural stock (eg, John Quincy Adams the Puritan). The cultural homogeneity back then was amazing. And the regions tended to vote a single way too. Now while some ethnic groups still vote heavily as a block (African-Americans vote 90% Democrat), most variation is whether married (Unmarried women voted for Kerry by a 25-point margin while married women voted for President Bush by an 11-point margin) or have children (74 percent of the variation in Bush’s shares is explained by each state’s white fertility rate!). Thus now you can predict more based on choices (marriage and fertility) than by birth (with some exceptions), wich is a good thing.

As much as people complain about the great divide in America today, we seem significantly more agreeable than the four major cultures that founded what became the USA, each of whom considered the others savage or profane. “Early America,” observes John Roche, “was an open country dotted with closed enclaves.”

For many adolescent girls, pregnancy may be no accident.

As social scientists and health educators grapple with causes of adolescent pregnancy in the United States, some researchers suggest that one component of the problem has been largely ignored. Though most adolescent pregnancies are accidental, a substantial number of girls want to get pregnant.

Susan L. Davies, Ph.D., of the University of Alabama at Birmingham's School of Public Health and colleagues, questioned 455 low-income, African-American adolescent girls in Birmingham, Ala., aged 14-18 between 1996 and 1999, and found that nearly a quarter (23.6 percent) expressed some desire to become pregnant in the near future. /* Of 522 participants (14 to 18 years old), 67 (12.8%) [sic] were pregnant and were thus excluded from this analysis */

''Adolescent pregnancy research has predominantly focused on factors associated with pregnancy occurrence and overlooked the possibility that pregnancy is a desired outcome for some adolescents,'' Davies says. Instead, she adds, successful pregnancy prevention programs need to discern between factors that contribute to intentional versus accidental pregnancies among teen girls.

In their research, published in the August 2004 issue of Health Education & Behavior, Davies and her team tried to identify some of those factors. Self-administered questionnaires asked participants about their desire to be pregnant, their relationships with males and their birth control use.

The most striking data revealed that adolescent girls with at least some desire to be pregnant were three-and-a-half times more likely to have a boyfriend or partner at least five years older, were more than twice as likely to have had sex with a casual partner in the six months prior to the survey and also more than twice as likely to have used condoms inconsistently in the prior month.

While the researchers say the likelihood of a significantly older partner was surprising, the frequency of girls with a desire to be pregnant having casual sexual partners was more telling.

''These findings suggest that the perceived role of the male partner in parenthood, other than to assist with conception, may be minimal from the adolescent girl's perspective,'' Davies says.

Considering that adolescent girls who want to be pregnant behave in ways that will help them meet their goal, researchers say, public health practitioners and policy makers will need to address this particular population with a tailored campaign. Some suggestions the researchers make include education to help this population understand the realities of motherhood, amending health education programs that assume adolescents regard pregnancy as negatively as they view HIV and other STDs, and increasing public recognition that adolescent childbearing is ''a symptom of larger social and economic predicaments.''

Yup, teach 'em economics!

via Science Blog

BERLIN (Reuters) - More than 80 percent of single German women are perfectly happy without a man in tow and say living solo gives them more freedom to do what they want, according to a survey for Stern magazine. Coming amid mounting political alarm about Germany's low birthrate and aging population, the survey of 1,003 women showed only two percent did not enjoy their solitary lifestyle and 36 percent opted to stay single because it was more fun.

Almost half the women said they preferred single life because it was easier to keep their homes tidy and 36 percent said with no man on the scene they didn't have to endure watching sports on television.

/* ;-DDD */

"It is surprising that intellectuals oppose capitalism so. Other groups of comparable socio-economic status do not show the same degree of opposition in the same proportions. Statistically, then, intellectuals are an anomaly.

Not all intellectuals are on the "left." Like other groups, their opinions are spread along a curve. But in their case, the curve is shifted and skewed to the political left.

By intellectuals, I do not mean all people of intelligence or of a certain level of education, but those who, in their vocation, deal with ideas as expressed in words, shaping the word flow others receive. These wordsmiths include poets, novelists, literary critics, newspaper and magazine journalists, and many professors. It does not include those who primarily produce and transmit quantitatively or mathematically formulated information (the numbersmiths) or those working in visual media, painters, sculptors, cameramen. Unlike the wordsmiths, people in these occupations do not disproportionately oppose capitalism. The wordsmiths are concentrated in certain occupational sites: academia, the media, government bureaucracy..." click here to continue reading.

by Robert Nozick
Arthur Kingsley Porter Professor of Philosophy at Harvard University

via Jakub