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December 31st, 2008 (Permalink)
Thank You!
Thanks to everyone who has supported The Fallacy Files since I last thanked you!
December 29th, 2008 (Permalink)
Celebrities Vs. Science
Isn’t it ironic in 1983 there were 10 shots [vaccinations] and now there’s 36 and the rise of autism has happened in the same time?―Jenny McCarthy
The British organization "Sense About Science" has put out a year-end review of the year's silliest celebrity comments on science. Some of the usual celebrity suspects make appearances, such as Jenny McCarthy―who can always be counted on to confuse causation with correlation. And some of the usual fallacy suspects appear, such as the appeal to nature, and―of course―the appeal to celebrity. Check it out!
Source: Leonor Sierra, with help from volunteers Julia Wilson and Oliver Fenwick, "Celebrities and Science 2008", Sense About Science, 12/27/2008 (PDF)
Via: Steve Connor, "Scientific illiteracy all the rage among the glitterati", The Independent, 12/27/2008
Update (12/31/2008): Oprah Winfrey may not be the silliest celebrity, but she is one of the most influential silly celebrities―for instance, she promoted the super-silly The Secret (see the Resource below). She also used her show to hype James Frey's fabricated memoir A Million Little Pieces, and another supposedly true story that has just been revealed as a hoax:
A man whose memoir about his experience during the Holocaust was to have been published in February has admitted that his story was embellished, and on Saturday evening his publisher canceled the release of the book. And once again a New York publisher and Oprah Winfrey were among those fooled by a too-good-to-be-true story. … This latest literary hoax is likely to trigger yet more questions as to why the publishing industry has such a poor track record of fact-checking.
Yes, but what about Oprah's record of fact-checking? Or, more accurately, her record of not fact-checking, or even logic-checking, what goes on her show. Apparently, the fact that the memoirist had already been on Oprah's show is one reason why his agent believed him:
"I believed the teller," Ms. Hurst said. "He was in so many magazines and books and on ‘Oprah.’ It did not seem like it would not be true."
What is Oprah's response?
In an e-mail message, a spokesman for Ms. Winfrey also declined to comment.
Perhaps in the future, she can give her spokesman a break from not commenting and have him check out the guests she has on her show.
Source: Motoko Rich & Joseph Berger, "False Memoir of Holocaust Is Canceled", The New York Times, 12/28/2008
Resource: Book Review: The Secret, Fallacy Files Book Shelf
December 21st, 2008 (Permalink)
A Reindeer Logic Game
From the following clues, can you determine the correct conclusion?
- All the flying reindeer belong to Santa Claus.
- Every flying reindeer lives at the North Pole.
- Only flying reindeer have red noses.
- Some red-nosed reindeer play reindeer games.
- None but red-nosed reindeer guide Santa's sleigh.
Which of the following propositions is a valid conclusion from the above clues? For extra credit, determine what fallacies would be committed by arguments from the clues to the incorrect propositions.
- None but Santa's reindeer live at the North Pole.
- Some of the reindeer that guide Santa's sleigh play reindeer games.
- Only Santa's reindeer guide his sleigh.
- Some flying reindeer guide Santa's sleigh.
December 20th, 2008 (Permalink)
In Dubious Data
The Statistical Assessment Service (STATS) has issued their annual "Dubious Data Awards" for the year's worst abuses of science and statistics in the media. Read the whole thing, but here are some points of special interest:
USA Today, the Milwaukee Sentinel Journal, and many other media organizations repeatedly turned to biologist Frederick Vom Saal to explain why BPA [Bisphenol A] is so dangerous, noting that he was a leading expert on the chemical. What the media failed to tell the public is that Vom Saal’s research has been rejected by not one, but two major risk assessments on BPA, both of which were carried out by independent scientists and both of which found no evidence of a risk to adults or infants.
This is an example of the all-too-common media practice of citing a single expert or study and ignoring the expert consensus. Of course, it's possible that Vom Saal is right and all the other experts wrong, but it's a journalistic responsibility to at least inform people that he is in the minority.
Fallacy: Appeal to Misleading Authority
There was a flood of media coverage of a study by an economist claiming that counties with high levels of rainfall in the Pacific Northwest had higher rates of autism among children. … Largely missing in [the] flurry of speculation over what accounted for the findings was that the study didn’t, in fact, report a direct link between rainfall levels and autism. Instead, they found a link between a "relative precipitation variable" and autism. Relative precipitation is a measurement of how far a county’s rain level is from the average level of precipitation. So the study is in fact saying that when rain levels are "out of the ordinary," autism is more likely to develop or be diagnosed.
If you go looking for a correlation and check enough variables, you're bound to find one, which is one reason why correlation is not causation. This certainly seems to be what has happened here, as there's no plausible mechanism for unusual weather causing autism.
Fallacy: Cum Hoc
A survey conducted by the Physicians' Foundation finds that almost half of all practicing physicians in the US plan to cut back or quit practicing medicine. According to the survey’s press release, "49 percent, or more than 150,000 practicing doctors―say that over the next three years they plan to reduce the number of patients they see or stop practicing entirely." But it turns out only four percent of respondents actually filled out a questionnaire…―begging the question of whether doctors closer to retirement, or unhappy doctors, are more likely to fill out a questionnaire to begin with. Without a representative sample of doctors, the survey only tells us something about the four percent who completed the survey, not everyone.
This survey is reminiscent of the famous Literary Digest poll fiasco (see the Resource below). Even though the sample was much larger than is usual for public opinion polls―almost 12,000―large sample size cannot make up for bias. By the way, I can't let them get away with that logically illiterate misuse of the phrase "begging the question". For shame!
Fallacies:
Source: STATS staff, "STATS 'Dubious Data' awards 2008", Statistical Assessment Service, 12/2008
Resource: How to Read a Poll, Fallacy Watch
December 19th, 2008 (Permalink)
Blurb Watch: Delgo
Here's something that I don't think I've seen before. Delgo is a dismally-reviewed new movie: its Metacritic Metascore is 27 out of 100, and its Tomatometer rating is 16%. The only blurb used in the ad for the movie is the single word "spectacular", attributed to USA Today.
When a blurb is attributed only to a publication, and not to a critic, this may mean that it's taken from the title of the review, since the title is often supplied by an editor, rather than the critic. However, in this case, the review of Delgo in USA Today does not contain the word "spectacular" in either its text or its title.
As we saw with Dark Streets, it's possible that the blurb is taken from some other article about Delgo other than USA Today's review. However, a web search reveals no articles in USA Today that contain both the title "Delgo" and the word "spectacular". Of course, it's still possible that the word "spectacular" occurs in some article that mentions Delgo in the print edition of USA Today. In fact, without a citation of the date and page number of the article, it's practically impossible to rule out.
No doubt the word "spectacular" has occurred at least once in USA Today. Normally, one assumes that a quote applies to the movie advertised, but nothing in the word "spectacular" itself indicates what it's talking about. Could that be the justification for the blurb? If so, this would be the most brazen contextomy that I've ever seen in a movie ad―and that's saying something!
Source: Claudia Puig, "'Delgo': A fantasy world not worth entering", USA Today, 12/12/2008
December 17th, 2008 (Permalink)
Illegitimate Headline
Two-Parent Black Families Showing Gains
That sounds encouraging, as the first paragraph of this New York Times article goes on to explain:
The number of black children being raised by two parents appears to be edging higher than at any time in a generation, at nearly 40 percent, according to newly released census data.
However, after a paragraph speculating as to a possible cause of this effect, it's disappointing to read:
The Census Bureau attributed an indeterminate amount of the increase to revised definitions adopted in 2007, which identify as parents any man and woman living together, whether or not they are married or the child’s biological parents.
So, apparently we can't tell how much of the increase is due to redefinition and how much, if any, is due to some real change. In fact, it's even possible that there has been a decline rather than a gain, which has been disguised by the change in definition. You can't tell that from the headline, though.
Sources: Sam Roberts, "Two-Parent Black Families Showing Gains", The New York Times, 12/17/2008
Via: James Taranto, "The New Legitimacy", Best of the Web Today, 12/17/2008
December 13th, 2008 (Permalink)
Check it Out
The Times of London has a new column on "bad statistics". The first, rather short, column gives a couple of examples of a bogus trend story in British newspapers; unfortunately, American newspapers aren't any better. Notice that even if the statistics supposedly supporting the trend were stronger, they really wouldn't show that the "credit crunch" is causing people to go to church―see the Fallacy listed below. Hopefully, future columns will be longer.
Source: Tom Whipple, "Bad statistics: turning to God", Times Online, 12/12/2008
Via: Ben Goldacre, "Rather brilliantly I have been plagiarised by the Times…", Bad Science, 12/12/2008
Fallacy: Cum Hoc
Update (12/24/2008): Oddly enough, shortly after the Times of London article was published, the New York Times ran a very similar one. Both claim that church attendance is rising, supposedly as a result of the economic downturn, but the Times of London places this phenomenon in England while its New York namesake has it in the United States. Perhaps journalistic minds think alike, or New York is getting story ideas from London. Both stories use the same dubious anecdotal statistics to support the case for increased attendance. Based on Gallup poll data showing no national rise in church attendance, Jack Shafer of Slate has denounced the New York Times article as the "bogus trend of the week".
Sources:
- Frank Newport, "No Evidence Bad Times Are Boosting Church Attendance", Gallup, 12/17/2008
- Jack Shafer, "Bogus Trend of the Week: Booming Evangelical Attendance", Slate, 12/22/2008
- Paul Vitello, "Bad Times Draw Bigger Crowds to Churches", The New York Times, 12/13/2008
December 12th, 2008 (Permalink)
Blurb Watch: Dark Streets
If you're writing an ad for a new movie, and all its reviews are negative, what do you do for a blurb? Suppose the movie has a Metacritic rating of 38, which means "generally negative reviews", and a Tomatometer rating of 16%. Since it's so hard to find a good review to quote, try quoting an article. That's what the adwriter did for the new movie Dark Streets. Mike Scott's comment comes not from his review of the movie, but from a report on the New Orleans Film Festival. It's likely that Scott had not even seen the film when he posted the article at 4:30 a.m., since the movie was scheduled to play at 8 p.m. The quote seems to be more a characterization of the movie than a recommendation. Scott's review, published this morning, gives the movie only two stars out of a possible four. Here's a blurb from that review that you won't be seeing:
Sources:
- Mike Scott, "The best of the New Orleans Film Festival: Day 7", The Times-Picayune, 10/16/2008
- Mike Scott, "Trip down atmospheric 'Dark Streets' is visually stunning", The Times-Picayune, 12/12/2008
December 11th, 2008 (Permalink)
New Look
It's been awhile since I updated this weblog, but I haven't been entirely idle. The front page, in case you haven't already noticed, has a somewhat new look. I've also been revamping various of the individual fallacy files. Most of these changes are cosmetic, but some are more substantial, one of which is individual taxonomies for each fallacy. Most of the entries still simply link to the "Type" of each fallacy, which is the next highest fallacy in the taxonomy. I'm gradually replacing the "Type" with the fallacy's entire branch of the taxonomy. In the long run, I intend to replace the current Taxonomy page with a similar tree diagram, which will be quite large and difficult to create, so it will be awhile before that is done.
So far, I haven't made "What's New?" entries in this weblog for these changes, because most are small and cosmetic. However, one substantive change to the front page is the addition of a link to the "Featured Fallacy", which currently is the Gambler's Fallacy. Instead of announcing every little change on the weblog, I'll link to the most recently revised fallacy. Also, when a new fallacy is added, it will become the "Featured Fallacy". I hope that you like the changes! If you have any comments, criticisms, or suggestions, please let me know.
December 2nd, 2008 (Permalink)
New Book
First, there was Nudge; now, there's Sway: Are one-syllable verb book titles the latest publishing fad? In the current issue of Skeptic magazine, Michael Shermer reviews this new book by Ori and Rom Brafman. The full title is: Sway: The Irresistible Pull of Irrational Behavior. I haven't read the review yet, as it's not online. However, the book has a positive―assuming that it's not taken out of context―blurb from Robert Cialdini. Even better, the blurbs come with the following disclaimer:
If you decide to buy this book because of these endorsements, you just got swayed. One of the psychological forces you’ll read about in Sway is our tendency to place a higher value on opinions from people in positions of prominence, power, or authority.
I like that. This could be the next Book Club book, if the publisher will send me a review copy. There is, of course, a website of the book, with the de rigueur blog.
Source: Sway
Update (12/15/2008): I've now read Shermer's review, and it's quite negative. He concentrates on the story of an airliner crash told in the book―you can read this story in an excerpt from the book available on the Sway website; see the Source below. It's a gripping tale, but I was skeptical of it even before reading Shermer's review, which calls it "baloney"―a word that Shermer seems fond of. The story is written in a fictive style that includes a lot mindreading of one of the pilots who was killed in the collision. How do the Brafman's know what he was thinking? Perhaps cockpit recordings and radio traffic with the tower reveal something of his thinking, but it still seems very speculative. Of course, the book may give a fuller account of their sources for this story.
The Brafmans attribute the crash largely to "loss aversion", which is certainly a plausible factor. However, in his review, Shermer gives an alternative account of the collision that includes many relevant details either missing from, or played down in, the excerpt. Shermer also doesn't cite any sources for these details, and all I know about the accident is what I've read in these two accounts, so I'm in no position to adjudicate. However, Shermer's account is more plausible in that it lacks the mindreading, and does not overemphasize any one cause of the crash. Moreover, an accident such as this is almost certain to have multiple causes, since several safety measures have to fail simultaneously. In this particular case, the accident would not have happened if the other pilot's plane had not been in the wrong place at the wrong time. According to Shermer, the fact that the pilot took off before he should have may have been due more to miscommunication with the tower than to loss aversion.
In any case, I'm still waiting for my review copy.
Sources:
- "Preview", Sway
- Michael Shermer, "Swayonomics", Skeptic, Volume 14, Number 3 (2008)
Answers to a Reindeer Logic Game:
- Invalid. Only clues 1 and 2 might allow us to connect Santa's reindeer with living at the North Pole. However, the argument from clues 1 and 2 to the conclusion commits the fallacy of illicit minor, because the minor term "North Pole reindeer" is distributed in the conclusion but not in the premiss.
- Invalid. Only clues 4 and 5 would allow us to connect the reindeer that guide Santa's sleigh to reindeer games. However, the middle term, "red-nosed reindeer", that would make the connection is undistributed in both premisses. So, the argument from clues 4 and 5 to the conclusion commits the fallacy of undistributed middle.
- Valid. From clue 5 we have that all the reindeer that guide Santa's sleigh have red noses, and from clue 3 we know that all red-nosed reindeer can fly. Putting these two clues together we can conclude that all reindeer that guide Santa's sleigh can fly. Then, from clue 1 we have that all the reindeer that guide Santa's sleigh belong to him, which means the same as the conclusion.
- Invalid. The only clues that would allow us to connect flying and guiding Santa's sleigh are 3 and 5. However, only clue 4 tells us that there are reindeer, and it only tells us that there are red-nosed reindeer who play reindeer games. Clue 5 only tells us that any reindeer that guides Santa's sleigh has a red nose. So, from the fact that there are red-nosed reindeer we can't conclude that there are any that guide Santa's sleigh. Therefore, the argument from clues 3 and 5 to the conclusion commits the existential fallacy.