Archives for April 17, 2022

Also Known as: Biased Statistics, Loaded Sample, Prejudiced Statistics, Prejudiced Sample, Loaded Statistics, Biased Induction

 

Description:

This fallacy is committed when a conclusion is made about a population based on a sample that is biased. It has the following form:

 

Premise:  Sample S, which is biased, is taken from population P.

Conclusion: Claim C made about Population P based on S.

 

This fallacy is a flawed Inductive Generalization:

 

Premise: X% of all observed A’s are B’s.

Conclusion: Therefore X% of all A’s are B’s.

 

An Inductive Generalization can be a good (strong) argument, provided that the sample is large enough (see the Hasty Generalization) and not biased. The fallacious version can be presented in this form:

 

Premise: X% of all observed A’s are B’s in biased sample S.

Conclusion: Therefore X% of all A’s are B’s.

 

Those committing the fallacy do not, of course, identify their sample as biased. They would present it as if it were a good (strong) Inductive Generalization and the sample would need to be evaluated to determine its bias.

The fallacy is committed when the sample is likely to be biased. A sample is biased or loaded when the method used to take the sample is likely to result in a sample that does not adequately represent the population from which it is drawn.

Biased samples are unreliable. As a blatant case, imagine a person is taking a sample from a bucket of colored balls.  Some of the balls are metal and some are plastic. If they used a magnet to select a sample, then the sample would include a disproportionate number of metal balls. In this case, any conclusions drawn about all the balls would be unreliable since there would probably be no plastic balls in the sample.

Biased samples are less likely to contain numbers proportional to the whole population. Bias is a relative concept and the same sample that is representative for one purpose could be representative for another.

For example, if a person wants to find out what most Americans thought about gun control, a poll taken at a large NRA (National Rifle Association) meeting would be a biased sample. But if they wanted to know what NRA members think, it would not be biased.

As another example, if a sample was taken at rally for gun control, that sample would also be biased if the goal was to determine what most Americans think about gun control. But if the goal was to determine the opinions of people who rally for gun control, the sample would not be biased.

Since the Biased Sample fallacy is committed when the sample (the observed instances) is biased or loaded, a good generalization requires an unbiased sample. The best way to do this is to take samples in ways that avoid bias. There are three general sample types aimed at avoiding bias. These methods (when used properly) will result in a sample that matches the whole population reasonably closely. Three types of samples are as follows:

 

Random Sample: This is a sample that is taken in such a way that only chance determines which members of the population are selected for the sample. Ideally, any individual member of the population has the same chance as being selected as any other. This type of sample avoids being biased because a biased sample is one that is taken in such a way that some members of the population have a higher chance of being selected than others. Unfortunately, creating an ideal random sample can be very difficult.

 

Stratified Sample: This is a sample that is taken by using the following steps: 1) The relevant strata (population subgroups) are identified, 2) The number of members in each stratum is determined and 3) A random sample is taken from each stratum in exact proportion to its size. This method is obviously most useful when dealing with stratified populations. For example, a person’s income often influences how she votes, so when conducting a presidential poll it would be a good idea to take a stratified sample using economic classes as the basis for determining the strata. This method avoids loaded samples by (ideally) ensuring that each stratum of the population is adequately represented.

 

Time Lapse Sample: This type of sample is taken by taking a stratified or random sample and then taking at least one more sample with a significant lapse of time between them. After the two samples are taken, they can be compared for changes. This method of sample taking is important when making predictions. A prediction based on only one sample is likely to be a Hasty Generalization (because the sample is likely to be too small to cover past, present, and future populations) or a Biased Sample (because the sample will only include instances from one time)

 

People often commit Biased Sample because of bias or prejudice. A person might intentionally or unintentionally seek out people or events that support their bias. As an example, a person who is pushing a particular scientific theory might tend to gather samples that are biased in favor of that theory. A person who is pushing a political narrative might gather samples that are most likely to seem to support their narrative.

People sometimes commit this fallacy from laziness or sloppiness rather than from bad intentions. It is easy to just take a sample from what is readily available rather than taking the time and effort to generate an adequate sample and draw a justified conclusion.

 

Defense: The defense against committing this fallacy is ensuring that your samples are not significantly biased. When considering a generalization made by someone else, the defense is to check to see if the sample is biased. If you have no way of determining this, you should suspend judgment.

 

Example #1:

Bill is assigned by his editor to determine what most Americans think about a new law that will place a federal tax on all modems and computers purchased. The revenues from the tax will be used to enforce new online decency laws. Bill, being technically inclined, decides to use an email poll. In his poll, 95% of those surveyed opposed the tax. Bill was quite surprised when 65% of all Americans voted for the taxes.

 

Example #2:

The United Pacifists of America decide to run a poll to determine what Americans think about guns and gun control. Jane is assigned the task of setting up the study. To save mailing costs, she includes the survey form in the group’s newsletter mailing. She is very pleased to find out that 95% of those surveyed favor gun control laws and she tells her friends that most Americans favor gun control laws.

 

Example #3:

Large scale polls were taken in Florida, California, and Maine and it was found that an average of 55% of those polled spent at least fourteen days a year near the ocean. So, it can be safely concluded that 55% of all Americans spend at least fourteen days near the ocean each year.

Also Known as: Circular Reasoning, Reasoning in a Circle, Petitio Principii

Description:

Begging the Question is a fallacy in which the premises include the claim that the conclusion is true or (directly or indirectly) assume the conclusion is true. This sort of “reasoning” typically has the following form.

 

Premises: Premises in which the truth of the conclusion is claimed, or the truth of the conclusion is assumed (either directly or indirectly).

Conclusion: Claim C, the conclusion, is true.

 

This is fallacious because assuming the conclusion is true (directly or indirectly) is not evidence for that conclusion. Simply assuming a claim is true does not serve as evidence for that claim. This is especially clear in particularly blatant cases: “X is true. The evidence for this claim is that X is true.”

Some cases of question begging are blatant, while others can be extremely subtle. While it might seem odd, a case of circular reasoning can be valid deductive argument. For example, this obviously circular reasoning is also valid:

 

Premise: P

Conclusion: P

 

It is valid because validity means that if the premises of an argument are all true, then the conclusion must be true. If P is true, then it follows that P is true. That is indeed hard to dispute. But assuming P is true does not give you a reason to accept that P is true and that is why circular reasoning is fallacious.

 

Defense: The defense is to consider whether the premises simply assume the conclusion is true. If they do, this fallacy is committed.

 

Example #1:

Bill: “God must exist.”

Jill: “How do you know.”

Bill: “Because the Bible says so.”

Jill: “Why should I believe the Bible?”

Bill: “Because the Bible was written by God.”

 

Example #2:

“If such actions were not illegal, then they would not be prohibited by the law.”

 

Example #3:

“The belief in God is universal. After all, everyone believes in God.”

 

Example #4:

Interviewer: “Your resume looks impressive, but I need another reference.”

Bill: “Jill can give me a good reference.”

Interviewer: “Good. But how do I know that Jill is trustworthy?”

Bill: “Certainly. I can vouch for her.”

Also Known As: Appeal to Hitler, Reductio ad Hitlerum, the Nazi Argument, the Hitler Card, the Nazi Card, Argument from Hitler

Description:

This fallacy is a specific instance of the Guilt by Association fallacy. But the excessive use of the argumentum ad Hitlerum on the internet, in politics, and elsewhere warrants it receiving its own entry.

It has the following general form:

 

Premise 1: Hitler (or some other Nazi, or Nazis in general) accepts claim C.

Conclusion: Therefore, claim C is false/wrong.

 

This is a fallacy because the mere fact that Hitler (etc.) accepted a claim (or acted in a certain way) does not show that the claim (or action) is wrong. Hitler presumably believed that 1+1=2 and if this reasoning was any good, it would have to be concluded that 1+1 does not equal 2, which is absurd.

This fallacy draws its psychological power from the negative view most people have towards the Nazis in general and Hitler in particular. This fallacy is sometimes used in bad faith argumentation by people who do not particularly dislike some aspects of Nazism but believe their opponents do and hence accuse them of being like Hitler or the Nazis. People using this fallacy also sometimes lie about what the Nazis believed or did to try to unjustly smear something with Nazism. While lying is not a fallacy, this is a bad faith tactic.

Attacking a person by comparing them to Hitler (or Nazis) to “disprove” their claim would usually be an Ad Hominem attack.

Comparisons to Hitler, Nazis and Nazism need not be fallacious. For example, a strong Argument by Analogy could be used to show that a modern political group is a Nazi group. So, it should not be assumed that all references to Hitler or Nazis in argumentation must be fallacious. To reject an argument simply because of such references would also be a fallacy.

 

Defense: While there can be good arguments that refer to the evils of the Nazis, you should be on guard whenever an argument compares anything to Hitler or the Nazis. You should ask whether this comparison is accurate and whether the comparison supports the claim being presented.

 

Example #1

Lee: “So, you are a vegetarian now.”

Rachel: “Yes. Well, I am trying.”

Lee: “You know that Hitler was a vegetarian, right?”

Rachel: “Really?”

Lee: “Yes. He also hated tobacco smoking.”

Rachel: “Quick, get me some bacon and a pack of cigarettes! I repudiate my views!”

 

Example #2

Ricardo: “Hmm, there seem to be some good arguments for having national health care.”

Glenda: “Oh, really?”

Ricardo: “Yes. After all, we have national defense against human enemies and even a federal agency for disasters. Why not have a comparable national defense against diseases and health problems?”

Glenda: “Why not indeed. You know that the Nazis were for national health care. They also killed all those people in the death camps. You are not proposing a final solution to health care, are you?”

Ricardo: “I watch the History Channel, so yeah, I know. But what does that have to do with national health care?”

Glenda: “I’m just connecting the dots.”

Ricardo: “Uh huh.”

Also Known As: Appeal to Snobbery

Description:

This fallacy occurs when an appeal to vanity or elitism is taken as evidence for a claim. It has the following form:

 

Premise 1: V is presented, with the intent to appeal to the vanity or snobbery of person P.

Premise 2: Therefore, claim C is true.

 

This is fallacious because appealing to a person’s vanity or snobbery is not evidence.  Such an appeal can be psychologically effective because people can be influenced by a desire to think of themselves as part of an elite group.

While vanity and snobbery can be moral flaws, they are not in themselves fallacious. It is their use in place of evidence that results in the fallacy occurring.

This fallacy is often employed in advertising by trying to motivate purchasing a product because it is associated with someone famous or that having the product somehow makes a person part of a special group. It is also used in politics, religion, and similar identity-based contexts. For example, a politician might try to motivate their followers to accept a claim by asserting that they are the real elites because they believe what they are saying. While this fallacy can be combined with Appeal to Group Identity in such contexts, they are different. Appeal to Group Identity gets its psychological force from the positive feelings the target has towards the group they identify with while the Appeal to Vanity gets its power from vanity or snobbery. If I believe a claim because I am proud to be a philosopher, then I would be committing an Appeal to Belief. If I accept a claim because I think I am better than everyone else because I am a philosopher and philosophers are the best, then I would be committing an appeal to vanity.

 

Defense: While it is appealing to think of oneself as among the elite, an appeal to vanity or snobbery provides no evidence for a claim. If someone is attempting to appeal to your vanity or snobbery, the defense is to ask whether there is any evidence for the claim they want you to accept. If there is not, you should not accept the claim on the basis of this appeal.

 

Example #1

“Ben Affleck wears the finest suits. Of course, he buys then at the Harvard Yard Suit & Baked Bean Emporium. You should too.”

 

Example #2

“Such a fine watch is not for everyone, but only for those who can truly appreciate a majestic time piece. If you are one of the select few, you may arrange an appointment with one of our agents to discuss purchasing opportunities. We do not accept walk-ins.”

 

Example #3

“You, my supporters are not just the elite. You are the super-elite. Like me. We have more money, and we are smarter. Our houses are better. Our boats are much nicer. The best boats. You are the super-elite. We are the super-elite. So, you know I am right when I say that we need more gun control. We cannot allow the non-elites to run around with so many guns.”