Fallacies of Logic
Correlation is not Causation (Post Hoc Ergo Propter Hoc)
When an event happens in close proximity to another event, it can be easy to assume that the first caused the second. Social phenomena always have multiple, conjoined, non-linear causes — it is the researcher that has to simplify things. “John played a lot of violent video games. Then John did this this awful deed, so the violent video games must have caused John to do the awful deed.” John may have often played violent video games before behaving badly, but demonstrating that violent video games caused the bad behavior and the particular awful deed requires complex, multi-faceted evidence. This fallacy can also be used in reverse, to deny any connection between facts. “Student workloads have increased, and the college dropout rate has also increased. However, students also suffer more psychological damage in high school these days, so the increased workloads in college must not be the real source of the problem.” Psychological damage in high school may be part of the problem, but that doesn’t mean student workloads should be dismissed as a causal factor. This fallacy can appear in quantitative social science, which often relies on correlational statistics. Whether or not traditional statistical models support causal arguments depends on the study design.
Begging the Question (Petito Principii)
This fallacy usually occurs when researchers misread their audience, treating an arguable proposition as if it were a fact. “Because students are no longer concerned about receiving a broad range of knowledge in college, the university should not require courses outside a student’s major.” In some research communities, everyone would agree that students no longer want a broad range of knowledge. Across broad discipline, or among policy makers and journalists, this assertion would be highly debatable. For example, a social scientist may present “because I said so!” as a justification, but doing so begs the question, “why say so?” This fallacy can often take the form of complex questions such as “Have you given up falsifying your data?” This fallacy can appear when a researcher is writing for a cross-over journal, the disciplinary flagship journal, or an audience of non-specialists.
Hasty Generalization (Dicto Simpliciter)
We often generalize in order to prove our points, and this is not necessarily bad. We rarely come up with an absolute truth, and natural scientists also have to use generalization to prove their theorems. These generalizations are only considered fallacies when the sample we take is unrepresentative. Using three people who voted for a Presidential candidate does not prove that most voters voted for that candidate; you would need a larger sample to make that assertion responsibly. Convincing an audience that a sample is representative is one of the great challenges of social research, and if conclusions are unsafe the researcher will be accused of hasty generalization. This fallacy can also be called a converse accident. “That man is an alcoholic. Liquor should be banned.” Hasty generalizations are usually found in the conclusions of academic articles and books — the points in a manuscript where a researcher has to make their findings seem important and transportable.
Circular Logic (Circulus in Probando)
Circular logic occurs when the reasons offer in support of an argument simply restate the argument itself. “To succeed in college, students need to effectively manage their time because success comes from a balance of work and social time.” Students need to balance their time because they need to balance their time. Circular arguments are ineffective because they don’t provide support for the author’s opinion, they just restate the opinion. Culture and deviance are among the most difficult things for social scientists to study, because clumsy wording around findings can appear to offer circular logic. “These social deviants are peculiar and interesting because they do peculiar and interesting things.” “Culture explains what is going on here because these are unique and local phenomena.” Sometimes social researchers call culture a “black box” variable because it appears as both cause and effect.
The basic structure of all arguments involves three interdependent elements:
- Claim (also known as the conclusion)—What you are trying to prove. This is usually presented as your essay‘s thesis statement.
- Support (also known as the minor premise)—The evidence (facts, expert testimony, quotes, and statistics) you present to back up your claims.
- Warrant (also known as major premise)—Any assumption that is taken for granted and underlies your claim.
Consider the claim, support, and warrant for the following examples:
Claim: The No Child Left Behind Act (2001) has led to an increase in high school student drop-out rates.
Support: Drop-out rates in the US have climbed by 20% since 2001.
Warrant: (The claim presupposes that) it‘s a "bad" thing for students to drop out.
Claim: ADHD has grown by epidemic proportions in the last 10 years
Support: In 1999, the number of children diagnosed with ADHD was 2.1 million; in 2009, the number was 3.5 million.
Warrant: (The claim presupposes that) a diagnosis of ADHD is the same thing as the actual existence of ADHD; it also presupposes that ADHD is a disease.
Claims fall into three categories: claims of fact, claims of value, and claims of policy. All three types of claims occur in scholarly writing although claims of fact are probably the most common type you will encounter in research writing. Claims of fact are assertions about the existence (past, present, or future) of a particular condition or phenomenon:
Example: Japanese business owners are more inclined to use sustainable business practices than they were 20 years ago.
The above statement about Japan is one of fact; either the sustainable practices are getting more popular (fact) or they are not (fact). In contrast to claims of fact, those of value make a moral judgment about a phenomenon or condition:
Example: Unsustainable business practices are unethical.
Notice how the claim is now making a judgment call, asserting that there is greater value in the sustainable than in the unsustainable practices. Lastly, claims of policy are recommendations for actions—for things that should be done:
Example: Japanese carmakers should sign an agreement to reduce carbon emissions in manufacturing facilities by 50% by the year 2025.
The claim in this last example is that Japanese carmakers‘ current policy regarding carbon emissions needs to be changed.
For the most part, the claims you will be making in academic writing will be claims of fact. Therefore, examples presented below will highlight fallacies in this type of claim. For an argument to be effective, all three elements—claim, support, and warrant—must be logically connected.