LFotW: Tu Quoque

Tu quoque translates to “you too.” This is an attempt to justify wrong action because someone else also does it (two wrongs make a right). “My evidence may be invalid, but so is yours.” This fallacy is frequently committed by proponents of various alternative medicine modalities, who argue that even though their therapies may lack evidence some mainstream modalities also lack evidence.

LFotW: Confusing Correlation with Causation

This fallacy is similar to the post-hoc fallacy in that it assumes cause and effect for two variables simply because they occur together. This fallacy is often used to give a statistical correlation a causal interpretation. For example, during the 1990’s both religious attendance and illegal drug use were on the rise. It would be a fallacy to conclude that therefore, religious attendance causes illegal drug use. It is also possible that drug use leads to an increase in religious attendance, or that both drug use and religious attendance are increased by a third variable, such as an increase in societal unrest, or even just population. It is also possible that both variables are independent of one another, and it is mere coincidence that they are both increasing at the same time.

This fallacy, however, has a tendency to be abused, or applied inappropriately, to deny all statistical evidence. In fact this constitutes a logical fallacy in itself, the denial of causation. This abuse takes two basic forms. The first is to deny the significance of correlations that are demonstrated with prospective controlled data, such as would be acquired during a clinical experiment. The problem with assuming cause and effect from mere correlation is not that a causal relationship is impossible; it’s just that there are other variables that must be considered and not ruled out a-priori. A controlled trial, however, by its design attempts to control for as many variables as possible in order to maximize the probability that a positive correlation is in fact due to a causation.

Further, even with purely epidemiological, or statistical, evidence it is still possible to build a strong scientific case for a specific cause. The way to do this is to look at multiple independent correlations to see if they all point to the same causal relationship. For example, it was observed that cigarette smoking correlates with getting lung cancer. The tobacco industry, invoking the “correlation is not causation” logical fallacy, argued that this did not prove causation. They offered as an alternate explanation “factor x”, a third variable that causes both smoking and lung cancer. But we can make predictions based upon the smoking causes cancer hypothesis. If this is the correct causal relationship, then duration of smoking should correlate with cancer risk, quitting smoking should decrease cancer risk, smoking unfiltered cigarettes should have a higher cancer risk than filtered cigarettes, etc. If all of these correlations turn out to be true, which they are, then the smoking causes cancer hypothesis is supported above other possible causal relationship and it is not a logical fallacy to conclude from this evidence that smoking probably causes lung cancer.

Movie Review: Horton Hears a Who

Summary: CG movie about the Dr. Seuss book with Jim Carrey as the Horton voice.

Rating: 7.0 out of 10

Review: This was Jacob’s third movie (he’s 26 months old) and his first in a first run movie theater. So, a lot of my time was spent on worrying about him and not on the movie. But, Jacob did a great job. He was really into the previews and enjoyed all of the except for Ice Age 3. It scarred him with the dinosaur roared. Once the movie started, he got excited and sat through most of it while I force feed him crackers. I think he went through about a pound of crackers. Jacob kind of got fidgety during the boring parts, but he did a great job, overall.

Oh, the movie. It was very good, for what I watched. I thought visually, they did a perfect job. I can’t really say much more about it, because I honestly was just there to make sure Jacob enjoyed it. But, I think anyone, parent or not, would enjoy this movie.

Movie Review: Stranger Than Fiction

Summary: An IRS guy who is obsessed with numbers starts to hear a voice in his head. The problem is that the voice is narrating his actions and causing turmoil in his “perfect” life.

Rating: 7.0 out of 10

Review: I was expecting just another chick flick movie. I thought this was a movie about Will Ferrell playing an idiot but falling in love in a very romantic way. I’m not sure where I got that idea, because it was nothing like that. This was actually a very good, quirky movie. The main character, Harold Crick, is an IRS agent who lives his life through numbers. Numbers involve everything he does, from counting his steps, to timing the bus, to calculating probabilities in everyday life. To go along with this, the movie had a very cool computer interface that floated around the whole movie. It help the audience to see the world as Harold Crick sees the world. He also reminded me of me. A bit too much. Maybe that’s why I liked it so much. Once Harold Crick starts hearing the voice, it starts to make him question his choices in everything he does. I won’t give too much away, but the rest of the movie is about Harold Crick figuring out the voice and what he’s going to do about it. The movie is pretty good and Will Ferrell does a decent job acting in this straight role.

Movie Review: Transformers

Summary: A war re-erupts on Earth between two robotic clans, the heroic Autobots and the evil Decepticons, leaving the fate of mankind hanging in the balance. Based on the great cartoon in the 80s.

Rating: 7.5 out of 10

Review: I love Transformers. I grew up with the cartoon and had tons of the actual transformers growing up. First of all, the movie did a pretty good job bringing me back to my childhood. It was fun to watch and try to remember the names of the transformer characters. In terms of action, this movie has it all. There are some fantastically epic battles. My only gripe in the action category is that some of the fights were so fast that it was hard to pick out what was going on. It was just a blur of metal rolling around and destroying the city. The actual transformations of the characters were really good. I wish I had one of those as a figure. The plot was the weakest part of the movie. It wasn’t really bad; it was just an excuse to see big, sentient robots fighting one another. My last gripe was that some of the dialogue did not seem to fit the characters. The humor from the transformers wasn’t always smooth. Some of the puns and one-liners took the viewer out of the movie and were not needed. Other than a mediocre plot, this was a great movie with some kick ass battles.

LFotW: Post-hoc ergo propter hoc

This week's logical fallacy is Post-hoc ergo propter hoc.

This is perhaps the most common of logical fallacies. It follows the basic format of A preceded B, therefore A caused B, and therefore assumes cause and effect for two events just because they are temporally related (the Latin translates to “after this, therefore because of this”). This logical fallacy is frequently invoked when defending various forms of alternative medicine - I was sick, I took treatment A, I got better, therefore treatment A made me better. It is possible to have recovered from an illness without any treatment.

Keep in mind (as with the correlation and causation fallacy described later) it is possible that A did cause B. The logical fallacy is in assuming causation. It is still valid to argue for causation if there is independent evidence to support a causational relationship over other interpretations, such as coincidence.

LFofW: Argument from final outcome or consequences

The logical fallacy for this week is Argument from Consequence. Such arguments (also called teleological) are based on a reversal of cause and effect, because they argue that something is caused by the ultimate effect that it has, or purpose that is serves. This argument takes some permutation of the form that if a claim were either true or untrue, then the consequences would either be good or bad, and therefore what is true is what leads to either achieving a good outcome or avoiding a bad outcome.
For example, Christian creationists have argued that evolution must be wrong because if it were true it would lead to immorality.

Subtype: Argument from Benefit
Another common, and perhaps more subtle, form of this logical fallacy is the notion that if someone or some entity benefited from an event they must have caused the event. This fallacy is commonly invoked in the context of the JFK assassination in order to support an alleged conspiracy. The argument is that if someone benefited from the assassination of JFK they must have been involved in a conspiracy to carry out the assassination.

Subtype: Appeal to Fear
The appeal to fear is an argument from consequences, but in this case the consequences are individually relevant – an outcome to be personally feared. For example, proselytizers often argue that you should accept the claims of their religion for if you reject them you risk eternal damnation.

Subtype: Appeal to Flattery
Like the appeal to fear, this is a personalized version of the argument from final consequences, this time positive rather than negative. This logical fallacy is the attempt to convince someone of a claim because of implied flattery. For example, alleged psychics may support their claims of psychic abilities by claiming that they sense psychic potential in the person they are trying to convince.

Subtype: Appeal to Pity
This fallacy attempts to support a claim out of pity, sympathy, or even obligation to some person or group. For example, some proponents of Gulf War Syndrome have argued that we should accept the reality of this syndrome because we owe it to our veterans who fought for us in the Gulf War. Another example is the claim that silicone breast implants cause autoimmune disease, despite all evidence to the contrary. During this debate there were many appeals to pity for the victims of silicone breast implants. This can also be considered the fallacy of assuming the conclusion, because having sympathy for the victims of silicone breast implants assumes they are victims, which is the very matter of debate.