The Unz Review - Mobile
A Collection of Interesting, Important, and Controversial Perspectives Largely Excluded from the American Mainstream Media
Email This Page to Someone

 Remember My Information

 TeasersiSteve Blog
Birth Order

Bookmark Toggle AllToCAdd to LibraryRemove from Library • BShow CommentNext New CommentNext New Reply
🔊 Listen RSS
Birth order theories (e.g., first-borns tend to be more risk-averse) have been around for a long time without making all that much progress. The data is very complicated and how exactly do you specify what you are looking for?
Well, here’s an NYT article on a small study that is well-defined enough that they might have actually found something:

In the current issue of Personality and Social Psychology Review, Frank J. Sulloway and Richard L. Zweigenhaft went digging for evidence of siblings behaving differently in the vast database of baseball statistics. Given how younger siblings have been shown to take more risks than their older counterparts — perhaps originally to fight for food, now for parental attention — Drs. Sulloway and Zweigenhaft examined whether the phenomenon might persist to the point that baseball-playing brothers would try to steal bases at significantly different rates.

In fact they did: For more than 90 percent of sibling pairs who had played in the major leagues throughout baseball’s long recorded history, including Joe and Dom DiMaggio and Cal and Billy Ripken, the younger brother (regardless of overall talent) tried to steal more often than his older brother….

UPDATED: A reader tries to reproduce this just for brothers where both were batters (i.e., no pitchers) and finds younger brothers more likely to steal in only 56% of the pairs

“We tend not to exhibit birth-order differences all the time in adulthood — we employ them in situations with siblings, because that’s where the behavior comes from,” Dr. Sulloway said. “But we found that here, and that’s significant.” …

In other words, Sulloway is making a fairly limited claim for the effects of birth order — birth order has more effect within the family than in the outer world. The oldest son is much more likely to become CEO than the youngest son of the family firm, but not all that much more likely to become CEO of a publicly traded company.

And there remains the plausible issue of whether younger brothers learned baseball strategy more fully simply by watching their older brothers growing up, which Dr. Zweigenhaft, a professor of psychology at Guilford College in Greensboro, N.C., said could very well be a contributing factor.  

Another explanation about why this study’s finding might be restricted to baseball might be that when brothers play on the same team growing up, the older brother will usually be stronger (because he’s more mature), and thus be put lower in the batting order in a slugger’s RBI slot. In contrast, the younger brother will bat higher in the order where players are more expected to steal.

For example, say you are lucky enough as a high school baseball coach to have two future major leaguers on your team, a pair of brothers two years apart, Al and Ben. Both are much more coordinated at putting the bat on the ball than all your other players. Where do you put them in the batting lineup? When the older one Al was a 150-pound sophomore, you had him batting third or fourth (clean-up) to maximize the number of runs he could drive in because even though he was still thin, he was so much better at hitting the ball than anybody else. But when Al’s a 180 pound senior and and his younger 150-pound brother Ben is a sophomore, you still have Al in the RBI slot, but you put Ben in the leadoff slot so he can get on base and steal.

So, by virtue of being older, Al is never given training as a leadoff batter, but Ben, by virtue of being stuck on Al’s team, is trained to get on base and steal so his big brother Al can drive him in.

Here’s my 1996 book review from National Review of Sulloway’s book Born to Rebel.

(Republished from iSteve by permission of author or representative)
• Tags: Birth Order, Sports 
🔊 Listen RSS

Something that’s important to keep in mind in all the hoopla over the Norwegian study of conscripts showing a few point higher IQs for oldest brothers, with the New York Times running three articles on the subject over the last week, is that small differences in IQ scores like this can be influenced by methodological issues of specific tests.

Now, big differences in average IQ, such as 15 points (one standard deviation), are test-independent. For decades, the Holy Grail of cognitive test designers has been to invent a test on which blacks and whites would average the same, without losing most real world predictive power. The first psychometrician to accomplish this would be rich and celebrated. Unfortunately, it has turned out to be the equivalent of the perpetual motion machine for engineers and cold fusion for physicists.

But small differences are sensitive to test design trade-offs. For example, the U.S. military’s 1979 version of its very heavily g-loaded entrance exam for enlistment applicants, the Armed Forces Qualifying Test, found an anomalously large 18.6 point gap between whites and blacks when it was standardized on the National Longitudinal Study of Youth in 1980 (this is the study that provides much of the new data in The Bell Curve). The average study has found a 16.5 point difference, so this 18.6 point gap was strange because the AFQT is a test the military has spent a fortune developing, and the NLSY sample, with about 13,000 participants including an oversampling of minorities, was the gold standard for a nationally representative data set..

The 1979 AFQT was designed to be highly accurate around IQs of 100. For instance, from 1992-2004, the military took very few applicants with IQs of 90, but would take quite a few 95s.

So, the 1979 AFQT was designed to be extremely thorough for the average person: it was 105 pages long! As Charles Murray pointed out recently, in the 1990s it was finally realized by studying results on a question-by-question basis that the length of the test had a downside that explained the unusually large 18.6 point white-black gap. Low IQ applicants, especially black males, often got discouraged by all the questions they couldn’t answer and would give up, either not filling in the rest or bubbling in the rest of the way.

In 1997, the 105 page paper and pencil AFQT was replaced with a computerized test that dynamically changed the test to reflect performance so far. For instance, if you missed a lot of early questions, the computer would serve up easier questions. The white-black gap turned out to be 14.7 points on the 1997 normalization of the computerized AFQT.

Unfortunately, we don’t know enough to be able to divvy up this 3.9 point narrowing of the white-black gap from one version of the AFQT to the next between the test methodology change and actual change in the size of the gap.

Somewhat similarly, Half Sigma hypothesizes that the brother result on the Norwegian equivalent of the AFQT is caused by older brothers being more conscientious. Perhaps they study harder in school and thus do better on the parts of the test that are less g-weighted. Or perhaps they just don’t give up as easily.

Or this could be a real result.

The point is, however, that it’s exactly backward for the media to get all worked up over one study reporting a 3 point difference between demographic groups (older and younger siblings) while ignoring the dozens of studies reporting much larger differences between demographic groups, such as between whites and Hispanics — especially because the Senate is voting on an immigration bill right now!

The best estimate I’ve yet seen of Hispanic-American IQs is the 2001 meta-analysis by Roth of 39 studies covering a total 5,696,519 individuals in America (aged 14 and above). It came up with an overall difference of 0.72 standard deviations in g (the “general factor” in cognitive ability) between “Anglo” whites and Hispanics. The 95% confidence range of the studies ran from .60 to .88 standard deviations, so there’s not a huge amount of disagreement among the studies.

One standard deviation equals 15 IQ points, so that’s a gap of 10.8 IQ points, or an IQ of 89 on the Lynn-Vanhanen scale where white Americans equal 100. That would imply the average Hispanic would fall at the 24th percentile of the white IQ distribution. This inequality gets worse at higher IQs Assuming a normal distribution, 4.8% of whites would fall above 125 IQ versus only 0.9% of Hispanics, which explains why Hispanics are given ethnic preferences in prestige college admissions.

In contrast, 105 studies of 6,246,729 individuals found an overall average white-black gap of 1.10 standard deviations, or 16.5 points. (I typically round this down to 1.0 standard deviation and 15 points). So, the white-Hispanic gap appears to be about 65% as large as the notoriously depressing white-black gap.

So, the white-Hispanic IQ gap is about what you’d guess from observing life around you with your lying eyes: not as big and deleterious as the white-black gap, but not trivial either.

If a 3 point IQ difference between brothers is worth three articles in the New York Times, you might think that an eleven point gap between whites and Hispanics would be worth, oh, say, eleven articles, especially when the immigration bill is up for debate in the Senate. But almost nobody has ever mentioned Roth’s finding in the press.

(Republished from iSteve by permission of author or representative)
Steve Sailer
About Steve Sailer

Steve Sailer is a journalist, movie critic for Taki's Magazine, columnist, and founder of the Human Biodiversity discussion group for top scientists and public intellectuals.

The “war hero” candidate buried information about POWs left behind in Vietnam.
The evidence is clear — but often ignored
The unspoken statistical reality of urban crime over the last quarter century.
The major media overlooked Communist spies and Madoff’s fraud. What are they missing today?
What Was John McCain's True Wartime Record in Vietnam?