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September 28th, 2005 (Permalink)

Correlation ≠ Causation

According to a report in Britain's Times: "Religious belief can cause damage to a society, contributing towards high murder rates, abortion, sexual promiscuity and suicide, according to research published today."

However, that's not what the research says. The researcher, Gregory Paul, simply displays correlations between religiosity, measured in various ways by public opinion polls, and murder and abortion rates, together with rates of certain sexually transmitted diseases. Suicide rates weren't even correlated with religiosity. Moreover, Paul explicitly disavows that the research shows that religious belief causes the problems with which it is correlated.

Paul is mainly interested in debunking the claim―often made by religious people―that religiosity positively contributes to moral and law-abiding behavior, and the data does undermine that hypothesis. However, almost all of the negative correlation appears to be due to the fact that the United States has both a high rate of religiosity and high rates of murder, abortion, and venereal diseases. The other developed countries―mainly European democracies―tend to be clustered together with low levels of both religious faith and social problems, while the U.S. is an outlier. It appears that if the U.S. were left out, the correlation would probably disappear.

As far as the data show, it could just as easily be the case that the presence of these social problems contributes to higher rates of religious belief. Or, perhaps some unique aspects of U.S. history contribute to both its current social problems and high degree of religiosity. With the recent spate of damaging hurricanes in the U.S., it may well be that hurricane damage positively correlates with religious belief. Will the British Times tell us next that American religiosity caused Katrina?


September 26th, 2005 (Permalink)

Fact Checking the Whopper

Annenberg Political Fact Check has an article analyzing a recent newspaper ad from an anti-war coalition accusing the President and members of his administration of lying and quoting their alleged lies. There are six supposed lies quoted in the ad, and Fact Check analyzes five of them. I don't have anything to add or take away from the five "lies" that Fact Check fact checks, and will leave it to you to "read the whole thing", as they say. However, I will point out that the sixth so-called lie is actually the Cheney "reconstituted nuclear weapons" contextomy, which I've debunked ad nauseum over the last couple of years. Like a monster in a bad horror movie, it keeps coming back no matter how many times it's killed. I won't repeat the analysis here; see the Resources below for a full history of the quote.

It's odd that this is the only one of the "lies" that Fact Check fails to fact check, especially given that there is abundant debunking of it available on the web, and not just here. Moreover, it is by far the most misleading of the supposed lies. Of course, the ad uses the usual political low redefinition of "lie" to mean simply a false statement, rather than an intentional misstatement. However, Cheney's statement was not even a misstatement; he simply misspoke.

Source: "Anti-war Ad Says Bush, Cheney, Rumsfeld & Rice 'Lied' About Iraq", Annenberg Political Fact Check, 9/26/2005


September 24th, 2005 (Permalink)

What's New?

I've added a Reader Response, and my reply to it, to the entry for the fallacy of guilt by association.

September 22nd, 2005 (Permalink)


Life…is lived on a slippery slope: Taxation could become confiscation; police could become gestapos. But the benefits from taxation and police make us willing to wager that our judgment can stop slides down dangerous slopes.


Source: George F. Will, "Silliness On Stem Cells", Washington Post, 8/4/2005

September 21st, 2005 (Permalink)

Check 'Em Out

September 16th, 2005 (Permalink)


Nuclear Fallout Helps with Dating Corpses

That sounds like the plot of a Tim Burton movie!

September 14th, 2005 (Permalink)

Post Hurricane Post Hoc

In the wake of Hurricane Katrina, some commentators are jumping to the conclusion that global warming is responsible for its destructiveness. While there is a theoretical possibility that higher ocean temperatures could lead to more powerful hurricanes, no individual hurricane can be shown to be so affected. Moreover, most scientists who study hurricanes believe that we are moving from a period of low hurricane activity to one of greater activity―a change not caused by global warming. So, arguing that Katrina's ravages are the result of climate change commits a causal fallacy.

Addendum (9/15): To clarify the above post, this is what I am and what I am not criticizing: I am criticizing the "jumping to a conclusion" that Gelbspan and others do in claiming that the severity of Katrina was due to global warming. I do not mean to criticize the premiss that the globe is warming, nor do I claim that the conclusion that Katrina's severity was due to global warming is false. Rather, my point is that it is impossible to know whether climate change contributed to Katrina's destructiveness. There are two reasons for this ignorance:

  1. There is no way of telling how much, if any, of Katrina's destructiveness was caused by global warming. There were equally, and even more, destructive hurricanes prior to global warming, and it is impossible to differentiate between a hurricane that is destructive due to global warming and one that is just plain destructive.
  2. Most scientists who study hurricanes believe that they are becoming more severe due to cyclical changes which have nothing to do with global warming, so it may be that all of Katrina's destructiveness was due to these other causes. If this were not the case, there would be a plausible argument that global warming was responsible for Katrina's excessive destructiveness for lack of an alternative explanation. However, there is an alternative. Now, I am not a scientist who studies hurricanes myself, so I'm relying upon press reports for the expert opinions of those who do (see the Resources below). Of course, press reports are not always reliable, so caveat lector.

People frequently assume that if one criticizes an argument one is thereby claiming that the argument's conclusion is false. This is presumably because one reason to criticize an argument is believing that its conclusion is false. However, logicians such as myself are trained to analyze arguments whether or not they believe the conclusion. Moreover, it is quite possible to argue badly for something that is true; it happens all the time! So, when I criticize an argument in this weblog, or in the examples throughout the files, I am not taking a position on the truth-value of the conclusion.

Acknowledgment: Thanks to Thomas Derz.

Source: Ross Gelbspan, "Katrina's Real Name", Boston Globe, 8/30/2005


September 12, 2005 (Permalink)

The King's Evil

In the past, kings supposedly healed sickness with a touch of the hand; today, potential kings merely encourage the laying on of hands and other ineffective remedies. Nick Cohen has an article about the British royal family's embrace of quackery, including the following "magnificent reply" from a doctor's letter rebuking Prince Charles' phony authority in medicine:

"'The power of my authority comes with a knowledge built on 40 years of study and 25 years of active involvement in cancer research,' he declared. 'Your power and authority rest on an accident of birth. I don't begrudge you that authority, but I do beg you to exercise your power with extreme caution when advising patients with life-threatening diseases to embrace unproven therapies. It is in the nature of your world to be surrounded by sycophants who constantly reinforce what they assume are your prejudices. Sir, they patronise you! Allow me this chastisement.'"

Source: Nick Cohen, "Fatal Mumbo-Jumbo", The Observer, 8/28/2005

September 1, 2005 (Permalink)

What's New?

The fallacy of redefinition!

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