Average IQ by State: Honest Numbers at Last

One of the most popular Web postings of November 2004 was a table purporting to show that John Kerry had swept the 16 states with the highest average IQs (such as Connecticut with its 113 mean). George W. Bush, in contrast, had carried the 26 dumbest states (such as Utah at only 87).

The first person to post these data after the election exulted: "Wow, what can I say, in the first 24 hours over 540,000+ people viewed this page!"

I would guesstimate that total viewership of the IQ table ultimately approached ten million fellow Democrats —all consoling themselves with the thought that what they lacked in quantity of voters, they more than made up for in quality of brainpower.

But it was all a complete hoax. And I had already pointed it out the previous May. Then, The Economist magazine fell for an earlier Bush v. Gore 2000 version, which it later retracted.

Still, the question of average state IQ scores is one that millions find fascinating, so I'm glad that the scientific journal Intelligence has in press an article entitled Estimating state IQ: Measurement challenges and preliminary correlates [PDF file] by Michael A. McDaniel, a widely published professor at the Virginia Commonwealth University school of business. (Thanks to Dienekes's blog for the tip. We publish this new state IQ table here. The earlier hoax data is in the right hand column.)

How did McDaniel come up with these estimates? He used the federal government's National Assessment of Educational Progress math and reading test scores. That's a technique that I introduced in 2004 at the suggestion of Ken Hirsch.

In the second column of the new table are Dr. McDaniel's reasonable-sounding estimates of IQ, setting the national average on the NAEP tests at 100 and the standard deviation at 15.

McDaniel has added a refinement to my approach. There was this problem: NAEP scores for 4th and 8th graders are just from public school students. But in states with large black or Hispanic populations, there is substantial white flight from the public schools , lowering NAEP scores. For example, 13.7% of South Carolina's white students and 10.6% of California's are not in public schools. McDaniel adjusts for this, raising slightly the IQ estimates of states with heavy white flight. (State IQ was defined as "the average of mean reading and mean math scores.")

The relationship between state average IQ and partisanship turns out to be quite mixed. (In the new table, I've marked states that voted Republican in 2004 as red, while Democratic states are blue.) Comparing McDaniel's estimated IQ scores to Bush's share of the vote in 2004, I see virtually no correlation: just -0.12.

In other words, if you were told the state IQs, you'd be only a little more than one percent (-0.12 squared) of the way toward fully predicting the state-by-state results of the 2004 election. (In contrast, the correlation coefficient for the hoax IQ data with Bush's percentages by state was -0.85, or 72% toward a wholly accurate prediction.)

How do McDaniel's results compare to other good faith state-by-state IQ estimates?

A massively representative national IQ test last happened in 1960, when Sputnik scared the federal government into giving an IQ test to 366,000 high school students as part of Project Talent. Four decades later, McDaniel's NAEP-based IQ estimate still correlated at the high 0.63 level with Project Talent's old results.

In a mid-1980s study of Vietnam veterans, 4,321 took an IQ test, with results tabulated by their state of birth. The findings correlate 0.59 with McDaniel's. (Data from Project Talent and the Vietnam veterans can be found here.)

The Social Quotient website estimated IQs from SAT and ACT college entrance exams scores. The results have a correlation coefficient of 0.71 with McDaniel's numbers.

Finally, for whatever it's worth, the free Internet-based Tickle IQ test has published its averages by state. Tickle correlates 0.53 with McDaniel's numbers.

Examining McDaniel's data, you should first notice that even the largest difference between states' mean IQ—the 10.2 points between Massachusetts and Mississippi—is actually not at all enormous. And that's especially true compared to the differences among countries. There, gaps of 30 points or more are not uncommon (e.g. Austria vs. Congo-Zaire ).

The median Massachusetts student would score at the 61% percentile nationwide, and the median Mississippi student at the 35% percentile. This isn't a tremendous difference—but it would be noticeable if you moved from one state to another.

McDaniel notes:

"States with higher estimated state IQ have greater gross state product [per capita], citizens with better health, more effective state governments, and less violent crime."

You'll also observe from the map below (where the brighter states are indicated by the brighter colors) that the highest IQ states are extremely, shall we say, Northern. Six of the top eight (marked in yellow) border on Canada . Overall, there's a clear correlation between latitude and NAEP scores.

 

Why is that? As George Will coyly hinted in his obituary for Daniel Patrick Moynihan:

"The Senate's Sisyphus, Moynihan was forever pushing uphill a boulder of inconvenient data. A social scientist trained to distinguish correlation from causation , and a wit, Moynihan puckishly said that a crucial determinant of the quality of American schools is proximity to the Canadian border. The barb in his jest was this: High cognitive outputs correlate not with high per-pupil expenditures but with a high percentage of two-parent families. For that, there was the rough geographical correlation that caused Moynihan to suggest that states trying to improve their students' test scores should move closer to Canada."

S-u-r-e, Dan and George! It must be proximity to Canada!! Everybody knows that playing hockey makes people monogamous and smart!!!

What else could it be?

McDaniel explicitly lays out what Moynihan and Will only dared joke about:

"IQ at the individual level has strong correlates with race. There are large and intractable mean racial differences in IQ at the person level. The differences are termed intractable because they have been relatively constant across decades and have not been appreciably affected by environmental interventions ( Murray, 2005).Because racial composition of the state is a large magnitude correlate of state IQ, one cannot expect meaningful changes in estimated state IQ as long as state racial composition is relatively stable. While increased education expenditures and smaller class sizes are to be encouraged, the stability of the rank order of NAEP test data suggests that states are not going to alter their standing on estimated state IQ dramatically through such efforts."

McDaniel uses NAEP data from 1990 through 2005, a period of widely-trumpeted educational "reforms". Yet he found little change over time in which states scored well and which poorly.

More subtle than the racial differences among states, but still highly visible in the map above, are very old disparities in the intellectual orientation of the descendents of the white settlers who arrived mostly before 1776, as described in David Hackett Fischer's Albion’s Seed

English Puritans, who were literate and middle class, primarily settled New England. Their descendents spread west along the northernmost tier of states. They established the most prestigious colleges , which continue to attract smart young people from the rest of the country.

The English Quakers of Pennsylvania invited in Germans of similarly peaceful and productive dispositions . They settled along the mid-northern tier. They also tended to be above average in their emphasis on education, although not quite as scholarly as the Puritans.

Farther south, from West Virginia and Tennessee, through the Ozarks, into Oklahoma and out to the Central Valley of California, the feisty Scots-Irish found their homes. The finest pioneers, they didn't mind raising their kids far from a schoolhouse.

The coastal South attracted the southern English, who erected aquasi-aristocratic society with a well-educated elite and a poorly schooled mass.

OK, so what are the problems with the Hirsch-Sailer-McDaniel method of estimating state IQ scores?

  •  First, the NAEP isn't an IQ test; it's a school achievement test.

As McDaniel points out, numerous studies show that results on achievement and aptitude tests are highly correlated. Nonetheless, it is possible for public schools to improve (or, far more easily, to deteriorate), so some of the variation is no doubt related to school quality rather than the underlying IQ of the students.

For example, the often-denigrated state of Indiana outscores neighboring, and more prestigious, Illinois (as well as some other more fashionable states such as Oregon and Colorado). This might indicate that Indiana has been doing something right educationally in recent decades.

Be wary, though, of that popular and pernicious myth—that "all" we have to do to solve the problems caused by diversity is to fix education, and then every student will be an above-average Lake Wobegon child.

The unpalatable truth: while we know how we could do a better job of keeping out low IQ foreigners, we really don't have a clue how to turn their children into high, or even medium, IQ adults on average.

America has spent enormous amounts of money since the Great Society trying to narrow ethnic IQ and achievement gaps . We have only a little to show for it.

It is simple, however, to mess up education. California's schools, for instance, have been terribly stressed by massive immigration, which is one reason California's NAEP scores are so miserable: 48th in IQ, ahead of only traditional laggards Louisiana and Mississippi.

  • A second limitation in estimating IQ our way: the NAEP is given in English, so very recent immigrants score lower.

This accounts—partly—for the catastrophic performance by California, the nation's most populous state and high-technology leader. California was 49th in 2003 on 8th grade reading, while finishing "merely" 44th in mathematics , the universal language.

But sadly, the low achievement levels of Hispanics don't vanish even when subsequent generations learn English. In 1992, the last time the NAEP asked test-takers about country of birth, American-born Latinos scored 0.72 standard deviations worse than non-Hispanic whites. That's two-thirds as bad as the notoriously debilitating white-black gap.

  • Third, the most important limitation on our NAEP method: it provides IQ estimates for children, not adults.

That has major electoral implications. Marriage and fertility rates among whites differ systematically between Republican and Democratic states. So the ratio of smart children to smart adults tends to be higher in GOP states. In 2004, Bush carried all 25 states in which white women are married the most years between 18 and 45. He also won 25 of the 26 states with the highest white total fertility rates.

As I've pointed out, Republicans thrive where cheap housing prices and high wages relative to the cost of living provide "affordable family formation". The GOP's "family values" platform doesn't resonate much where many voters can't afford to form families.

Because the majority of prestigious colleges and jobs are located in coastal Democratic-voting states, there is an outflow of higher IQ youths from Republican-voting inland states, offset somewhat by a return flow of young couples looking for a more affordable place to raise their kids.

Unfortunately, higher IQ people in Democratic states don't reproduce at the replacement rate—in California, for example, white women average only 1.65 babies, well below the replacement rate of 2.05 to 2.10.

To overcome their failure to reproduce, white Democrats, such as the indefatigable Ted Kennedy , campaign for more immigration.

Immigrants tend to vote Democratic.   And, by raising land prices and lowering wages, immigration prevents native-born Americans from forming families—which discourages them from voting for Republican family-values candidates.

Simple, eh? In contrast, why George W. Bush (who still hasn't signed the 700-mile border fence bill passed by Congress in September) wants what Ted Kennedy wants is much less explicable.

[Steve Sailer [email him] is founder of the Human Biodiversity Institute and movie critic for The American Conservative. His website www.iSteve.blogspot.com features his daily blog.]