Nonsense about Presidents, IQ, and War

Peter Singer outdoes his usual tendentious self in this review of Steven Pinker’s The Better Angels of Our Nature: Why Violence Has Declined. In the course of the review, Singer writes:

Pinker argues that enhanced powers of reasoning give us the ability to detach ourselves from our immediate experience and from our personal or parochial perspective, and frame our ideas in more abstract, universal terms. This in turn leads to better moral commitments, including avoiding violence. It is just this kind of reasoning ability that has improved during the 20th century. He therefore suggests that the 20th century has seen a “moral Flynn effect, in which an accelerating escalator of reason carried us away from impulses that lead to violence” and that this lies behind the long peace, the new peace, and the rights revolution. Among the wide range of evidence he produces in support of that argument is the tidbit that since 1946, there has been a negative correlation between an American president’s I.Q. and the number of battle deaths in wars involving the United States.

Singer does not give the source of the IQ estimates on which Pinker relies, but the supposed correlation points to a discredited piece of historiometry by Dean Keith Simonton, “Presidential IQ, Openness, Intellectual Brilliance, and Leadership: Estimates and Correlations for 42 U.S. Chief Executives” (Political Psychology, Vol. 27, No. 4, 2006). Simonton jumps through various hoops to assess the IQs of  every president from Washington to Bush II — to one decimal place. That is a feat on a par with reconstructing the final thoughts of Abel, ere Cain slew him.

Before I explain the discrediting of Simonton’s obviously discreditable “research,” there is some fun to be had with the Pinker-Singer story of presidential IQ (Simonton-style) for battle deaths. First, of course, there is the convenient cutoff point of 1946. Why 1946? Well, it enables Pinker-Singer to avoid the inconvenient fact that the Civil War, World War I, and World War II happened while the presidency was held by three men who (in Simonton’s estimation) had high IQs: Lincoln, Wilson, and FDR.

The next several graphs depict best-fit relationships between Simonton’s estimates of presidential IQ and the U.S. battle deaths that occurred during each president’s term of office.* The presidents, in order of their appearance in the titles of the graphs are Harry S Truman (HST), George W. Bush (GWB), Franklin Delano Roosevelt (FDR), (Thomas) Woodrow Wilson (WW), Abraham Lincoln (AL), and George Washington (GW). The number of battle deaths is rounded to the nearest thousand, so that the prevailing value is 0, even in the case of the Spanish-American War (385 U.S. combat deaths) and George H.W. Bush’s Gulf War (147 U.S. combat deaths).

This is probably the relationship referred to by Singer, though Pinker may show a linear fit, rather than the tighter polynomial fit used here:

It looks bad for the low “IQ” presidents — if you believe Simonton’s estimates of IQ, which you shouldn’t, and if you believe that battle deaths are a bad thing per se, which they aren’t. I will come back to those points. For now, just suspend your well-justified disbelief.

If the relationship for the HST-GWB era were statistically meaningful, it would not change much with the introduction of additional statistics about “IQ” and battle deaths, but it does:

If you buy the brand of snake oil being peddled by Pinker-Singer, you must believe that the “dumbest” and “smartest” presidents are unlikely to get the U.S. into wars that result in a lot of battle deaths, whereas some (but, mysteriously, not all) of the “medium-smart” presidents (Lincoln, Wilson, FDR) are likely to do so.

In any event, if you believe in Pinker-Singer’s snake oil, you must accept the consistent “humpback” relationship that is depicted in the preceding four graphs, rather than the highly selective, one-shot negative relationship of the HST-GWB graph.

More seriously, the relationship in the HST-GWB graph is an evident ploy to discredit certain presidents (especially GWB, I suspect), which is why it covers only the period since WWII. Why not just say that you think GWB is a chimp-like, war-mongering, moron and be done with it? Pseudo-statistics of the kind offered up by Pinker-Singer is nothing more than a talking point for those already convinced that Bush=Hitler.

But as long as this silly game is in progress, let us continue it, with a new rule. Let us advance from one to two explanatory variables. The second explanatory variable that strongly suggests itself is political party. And because it is not good practice to omit relevant statistics (a favorite gambit of liars), I estimated an equation based on “IQ” and battle deaths for the 27 men who served as president from the first Republican presidency (Lincoln’s) through the presidency of GWB.  The equation looks like this:

U.S. battle deaths (000) “owned” by a president =

-80.6 + 0.841 x “IQ” – 31.3 x party (where 0 = Dem, 1 = GOP)

In other words, battle deaths rise at the rate of 841 per IQ point (so much for Pinker-Singer). But there will be fewer deaths with a Republican in the White House (so much for Pinker-Singer’s implied swipe at GWB).

All of this is nonsense, of course, for two reasons: Simonton’s estimates of IQ are hogwash, and the number of U.S. battle deaths is a meaningless number, taken by itself.

With regard to hogwash, Simonton’s estimates of presidents’ IQs put every one of them — including the “dumbest,” U.S. Grant — in the top 2.3 percent of the population. And the mean of Simonton’s estimates puts the average president in the top 0.1 percent (one-tenth of one percent) of the population. That is literally incredible. Good evidence of the unreliability of Simonton’s estimates is found in an entry by Thomas C. Reeves at George Mason University’s History New Network. Reeves is the author of A Question of Character: A Life of John F. Kennedy, the negative reviews of which are evidently the work of JFK idolators who refuse to be disillusioned by facts. Anyway, here is Reeves:

I’m a biographer of two of the top nine presidents on Simonton’s list and am highly familiar with the histories of the other seven. In my judgment, this study has little if any value. Let’s take JFK and Chester A. Arthur as examples.

Kennedy was actually given an IQ test before entering Choate. His score was 119…. There is no evidence to support the claim that his score should have been more than 40 points higher [i.e., the IQ of 160 attributed to Kennedy by Simonton]. As I described in detail in A Question Of Character [link added], Kennedy’s academic achievements were modest and respectable, his published writing and speeches were largely done by others (no study of Kennedy is worthwhile that downplays the role of Ted Sorensen)….

Chester Alan Arthur was largely unknown before my Gentleman Boss was published in 1975. The discovery of many valuable primary sources gave us a clear look at the president for the first time. Among the most interesting facts that emerged involved his service during the Civil War, his direct involvement in the spoils system, and the bizarre way in which he was elevated to the GOP presidential ticket in 1880. His concealed and fatal illness while in the White House also came to light.

While Arthur was a college graduate, and was widely considered to be a gentleman, there is no evidence whatsoever to suggest that his IQ was extraordinary. That a psychologist can rank his intelligence 2.3 points ahead of Lincoln’s suggests access to a treasure of primary sources from and about Arthur that does not exist.

This historian thinks it impossible to assign IQ numbers to historical figures. If there is sufficient evidence (as there usually is in the case of American presidents), we can call people from the past extremely intelligent. Adams, Wilson, TR, Jefferson, and Lincoln were clearly well above average intellectually. But let us not pretend that we can rank them by tenths of a percentage point or declare that a man in one era stands well above another from a different time and place.

My educated guess is that this recent study was designed in part to denigrate the intelligence of the current occupant of the White House….

That is an excellent guess.

The meaninglessness of battle deaths as a measure of anything — but battle deaths — should be evident. But in case it is not evident, here goes:

  • Wars are sometimes necessary, sometimes not. (I give my views about the wisdom of America’s various wars at this post.) Necessary or not, presidents usually act in accordance with popular and elite opinion about the desirability of a particular war. Imagine, for example, the reaction if FDR had not gone to Congress on December 8, 1941, to ask for a declaration of war against Japan, or if GWB had not sought the approval of Congress for action in Afghanistan.
  • Presidents may have a lot to do with the decision to enter a war, but they have little to do with the external forces that help to shape that decision. GHWB, for example, had nothing to do with Saddam’s decision to invade Kuwait and thereby threaten vital U.S. interests in the Middle East. GWB, to take another example, was not a party to the choices of earlier presidents (GHWB and Clinton) that enabled Saddam to stay in power and encouraged Osama bin Laden to believe that America could be brought to its knees by a catastrophic attack.
  • The number of battle deaths in a war depends on many things outside the control of a particular president; for example, the size and capabilities of enemy forces, the size and capabilities of U.S. forces (which have a lot to do with the decisions of earlier administrations and Congresses), and the scope and scale of a war (again, largely dependent on the enemy).
  • Battle deaths represent personal tragedies, but — in and of themselves — are not a measure of a president’s wisdom or acumen. Whether the deaths were in vain is a separate issue that depends on the aforementioned considerations. To use battle deaths as a single, negative measure of a president’s ability is rank cynicism — the rankness of which is revealed in Pinker’s decision to ignore Lincoln and FDR and their “good” but deadly wars.

To put the last point another way, if the number of battle death deaths is a bad thing, Lincoln and FDR should be rotting in hell for the wars that brought an end to slavery and Hitler.

* The numbers of U.S. battle deaths, by war, are available at, “America’s Wars: U.S. Casualties and Veterans.” The deaths are “assigned” to presidents as follows (numbers in parentheses indicate thousands of deaths):

All of the deaths (2) in the War of 1812 occurred on Madison’s watch.

All of the deaths (2) in the Mexican-American War occurred on Polk’s watch.

I count only Union battle deaths (140) during the Civil War; all are “Lincoln’s.” Let the Confederate dead be on the head of Jefferson Davis. This is a gift, of sorts, to Pinker-Singer because if Confederate dead were counted as Lincoln, with his high “IQ,” it would make Pinker-Singer’s hypothesis even more ludicrous than it is.

WW is the sole “owner” of WWI battle deaths (53).

Some of the U.S. battle deaths in WWII (292) occurred while HST was president, but Truman was merely presiding over the final months of a war that was almost won when FDR died. Truman’s main role was to hasten the end of the war in the Pacific by electing to drop the A-bombs on Hiroshima and Nagasaki. So FDR gets “credit” for all WWII battle deaths.

The Korean War did not end until after Eisenhower succeeded Truman, but it was “Truman’s war,” so he gets “credit” for all Korean War battle deaths (34). This is another “gift” to Pinker-Singer because Ike’s “IQ” is higher than Truman’s.

Vietnam was “LBJ’s war,” but I’m sure that Singer would not want Nixon to go without “credit” for the battle deaths that occurred during his administration. Moreover, LBJ had effectively lost the Vietnam war through his gradualism, but Nixon chose nevertheless to prolong the agony. So I have shared the “credit” for Vietnam War battle deaths between LBJ (deaths in 1965-68: 29) and RMN (deaths in 1969-73: 17). To do that, I apportioned total Vietnam War battle deaths, as given by, according to the total number of U.S. deaths in each year of the war, 1965-1973.

The wars in Afghanistan and Iraq are “GWB’s wars,” even though Obama has continued them. So I have “credited” GWB with all the battle deaths in those wars, as of May 27, 2011 (5).

The relative paucity of U.S. combat  deaths in other post-WWII actions (e.g., Lebanon, Somalia, Persian Gulf) is attested to by “Post-Vietnam Combat Casualties,” at

Related posts about war and peace:
Libertarian Nay-Saying on Foreign and Defense Policy
Libertarian Nay-Saying on Foreign and Defense Policy, Revisited
Libertarians and the Common Defense
Libertarianism and Pre-emptive War: Part I
An Aside about Libertarianism and the War
Right On! For Libertarian Hawks Only
Why Sovereignty?
Understanding Libertarian Hawks
More about Libertarian Hawks and Doves
Defense, Anarcho-Capitalist Style
War Can Be the Answer
Getting It Almost Right about Iraq
Philosophical Obtuseness
But Wouldn’t Warlords Take Over?
Sorting Out the Libertarian Hawks and Doves
Now, Let’s Talk About Something Else
Libertarianism and Preemptive War: Part II
Give Me Liberty or Give Me Non-Aggression?
My View of Warlordism, Seconded
The Fatal Naïveté of Anarcho-Libertarianism
Final (?) Words about Preemption and the Constitution
More Final (?) Words about Preemption and the Constitution
QandO Saved Me the Trouble
Thomas Woods and War
“Proportionate Response” in Perspective
Parsing Peace
Not Enough Boots
Defense as the Ultimate Social Service
I Have an Idea
September 11: Five Years On
How to View Defense Spending
Reaching the Limit?
The Best Defense . . .
More Stupidity from Cato
A Critique of Extreme Libertarianism
Anarchistic Balderdash
Not Enough Boots: The Why of It
Blood for Oil

It *Is* the Oil
The End of Slavery in the United States
Liberalism and Sovereignty
Cato’s Usual Casuistry on Matters of War and Peace
The Media, the Left, and War
A Point of Agreement
The Decision to Drop the Bomb
The “Predator War” and Self-Defense
The National Psyche and Foreign Wars
Delusions of Preparedness
A Moralist’s Moral Blindness
A Grand Strategy for the United States
The Folly of Pacifism
Why We Should (and Should Not) Fight
Rating America’s Wars
Transnationalism and National Defense
The Next 9/11?
The Folly of Pacifism, Again
September 20, 2001: Hillary Clinton Signals the End of “Unity”

Previous posts about Peter Singer:
Peter Singer’s Fallacy
Peter Singer’s Agenda
Singer Said It
Rationing and Health Care
Peter Presumes to Preach