8 logical fallacies that are hard to spot
From "if-by-whiskey" to the McNamara fallacy, being able to spot logical missteps is an invaluable skill.
- A fallacy is the use of invalid or faulty reasoning in an argument.
- There are two broad types of logical fallacies: formal and informal.
- A formal fallacy describes a flaw in the construction of a deductive argument, while an informal fallacy describes an error in reasoning.
In arguments, few things are more frustrating than when you realize that someone is using bad logic, but you can't quite identify what the problem is.
This rarely happens with the more well-known logical fallacies. For example, when someone in an argument starts criticizing the other person's reputation instead of their ideas, most people know that's an ad hominem attack. Or, when someone compares two things to support their argument, but it doesn't make sense, that's a false equivalency. But other fallacies are harder to spot. For example, say you're arguing about politics with a friend, and they say:
"The far-left is crazy. The far-right is violent. That's why the right answers lie the middle."
Sure, it might be true that moderation is the answer. But just because two extremes exist doesn't mean that the truth necessarily lies between those extremes. Put more starkly: If one person says the sky is blue, but someone else says it's yellow, that doesn't mean the sky is green. This is an argument to moderation, or the middle ground fallacy — you hear it a lot from people who are trying to mediate conflicts.
When you find yourself in arguments, it's valuable to be able to spot and, if necessary, call out logical fallacies like this. It can protect you against bad ideas. Check out a few more examples of logical fallacies that can be tough to spot.
Appeal to privacy
When someone behaves in a way that negatively affects (or could affect) others, but then gets upset when others criticize their behavior, they're likely engaging in the appeal to privacy — or "mind your own business" — fallacy. Examples:
- Someone who speeds excessively on the highway, considering his driving to be his own business.
- Someone who doesn't see a reason to bathe or wear deodorant, but then boards a packed 10-hour flight.
Language to watch out for: "You're not the boss of me." "Worry about yourself."
Sunk cost fallacy
When someone argues for continuing a course of action despite evidence showing it's a mistake, it's often a sunk cost fallacy. The flawed logic here is something like: "We've already invested so much in this plan, we can't give up now." Examples:
- Someone who intentionally overeats at an all-you-can-eat buffet just to get their "money's worth"
- A scientist who won't admit his theory is incorrect because it would be too painful or costly
Language to watch out for: "We must stay the course." "I've already invested so much...." "We've always done it this way, so we'll keep doing it this way."
This fallacy is named after a speech given in 1952 by Noah S. "Soggy" Sweat, Jr., a state representative for Mississippi, on the subject of whether the state should legalize alcohol. Sweat's argument on prohibition was (to paraphrase):
If, by whiskey, you mean the devil's brew that causes so many problems in society, then I'm against it. But if whiskey means the oil of conversation, the philosopher's wine, "the stimulating drink that puts the spring in the old gentleman's step on a frosty, crispy morning;" then I am certainly for it.
Note: If-by-whiskey really only becomes a fallacy when it's used to conceal a lack of position, or to dodge a tough question. In Sweat's speech, if-by-whiskey was an effective rhetorical device used to summarize two competing perspectives on alcohol, and to make his position clear.
RationalWiki provides an example of the usual format this fallacy takes:
"If by [noun], you mean [negative descriptors of noun], then of course [statement of lack of support/belief]. If, however, by [noun], you mean [positive descriptors of noun], then [statement of support/belief]."
This fallacy involves arguing against a position because you think choosing it would start a chain reaction of bad things, even though there's little evidence to support your claim. Example:
- "We can't allow abortion because then society will lose its general respect for life, and it'll become harder to punish people for committing violent acts like murder."
- "We can't legalize gay marriage. If we do, what's next? Allowing people to marry cats and dogs?" (Some people actually made this argument before same-sex marriage was legalized in the U.S.)
Of course, sometimes decisions do start a chain reaction, which could be bad. The slippery slope device only becomes a fallacy when there's no evidence to suggest that chain reaction would actually occur.
Language to watch out for: "If we do that, then what's next?"
"There is no alternative"
A modification of the false dilemma, this fallacy (often abbreviated to TINA) argues for a specific position because there are no realistic alternatives. Former British Prime Minister Margaret Thatcher used this exact line as a slogan to defend capitalism, and it's still used today to that same end: Sure, capitalism has its problems, but we've seen the horrors that occur when we try anything else, so there is no alternative.
Language to watch out for: "If I had a magic wand…" "What else are we going to do?!"
Ad hoc arguments
An ad hoc argument isn't really a logical fallacy, but it is a fallacious rhetorical strategy that's common and often hard to spot. It occurs when someone's claim is threatened with counterevidence, so they come up with a rationale to dismiss the counterevidence, hoping to protect their original claim. Ad hoc claims aren't designed to be generalizable. Instead, they're typically invented in the moment. RationalWiki provides an example:
Alice: "It is clearly said in the Bible that the Ark was 450 feet long, 75 feet wide and 45 feet high."
Bob: "A purely wooden vessel of that size could not be constructed; the largest real wooden vessels were Chinese treasure ships which required iron hoops to build their keels. Even the Wyoming which was built in 1909 and had iron braces had problems with her hull flexing and opening up and needed constant mechanical pumping to stop her hold flooding."
Alice: "It's possible that God intervened and allowed the Ark to float, and since we don't know what gopher wood is, it is possible that it is a much stronger form of wood than any that comes from a modern tree."
This fallacy occurs when someone doesn't really have a strong argument, so they just throw a bunch of irrelevant facts, numbers, anecdotes and other information at the audience to confuse the issue, making it harder to refute the original claim. Example:
- A tobacco company spokesperson who is confronted about the health risks of smoking, but then proceeds to show graph after graph depicting many of the other ways people develop cancer, and how cancer metastasizes in the body, etc.
Watch out for long-winded, data-heavy arguments that seem confusing by design.
Named after Robert McNamara, the U.S. secretary of defense from 1961 to 1968, this fallacy occurs when decisions are made based solely on quantitative metrics or observations, ignoring other factors. It stems from the Vietnam War, in which McNamara sought to develop a formula to measure progress in the war. He decided on bodycount. But this "objective" formula didn't account for other important factors, such as the possibility that the Vietnamese people would never surrender.
You could also imagine this fallacy playing out in a medical situation. Imagine a terminal cancer patient has a tumor, and a certain procedure helps to reduce the size of the tumor, but also causes a lot of pain. Ignoring quality of life would be an example of the McNamara fallacy.
Language to watch out for: "You can't measure that, so it's not important."
Join Radiolab's Latif Nasser at 1pm ET on Monday as he chats with Malcolm Gladwell live on Big Think.
University of Utah research finds that men are especially well suited for fisticuffs.
- With males having more upper-body mass than women, a study looks to find the reason.
- The study is based on the assumption that men have been fighters for so long that evolution has selected those best-equipped for the task.
- If men fought other men, winners would have survived and reproduced, losers not so much.
Built for mayhem<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzk4NTQ2OX0.my6nML12F3fEQu3H4G0BScdqgaMZkRQHxgyj-Cmjmzk/img.jpg?width=980" id="906fc" class="rm-shortcode" data-rm-shortcode-id="dd77af7a881631355ed8972437846394" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers are, of course, talking averages here, not stating a rule: There are plenty of accomplished female pugilists, as well as lots of males who have no idea how to throw a punch.</p><p>Even so, says co-author <a href="https://www.wofford.edu/academics/majors-and-programs/biology/faculty-and-staff" target="_blank">Jeremy Morris</a> says, "The general approach to understanding why sexual dimorphism evolves is to measure the actual differences in the muscles or the skeletons of males and females of a given species, and then look at the behaviors that might be driving those differences."</p><p>Carrier has been interested in the idea that millennia of male fighting has shaped certain structures in male bodies. Previous research has reinforced his hunch:</p> <ul> <li><a href="https://jeb.biologists.org/content/216/2/236" target="_blank">When a hand is formed into a fist, its structure is self-protective</a>.</li> <li><a href="https://unews.utah.edu/flat-footed-fighters/" target="_blank">Heels planted firmly on the ground augment upper-body power</a>.</li> <li><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909544" target="_blank">A study examined facial bone structure as being especially well-suited for taking a punch</a>.</li> </ul> <p>(That last one is our favorite. Do you know the German word "<a href="https://www.urbandictionary.com/define.php?term=Backpfeifengesicht" target="_blank">backpfeifengesicht</a>?" It's an adjective describing "a face that badly needs a punching.")</p><p>"One of the predictions that comes out of those," asserts Carrier, "is if we are specialized for punching, you might expect males to be particularly strong in the muscles that are associated with throwing a punch."</p>
Testing the theory<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIzMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzMxMTE2MH0.UXJICMy57UPYUWskhK98alctOrPidJL9yxMkz3HDQrM/img.jpg?width=980" id="98718" class="rm-shortcode" data-rm-shortcode-id="b12287684ac3e740b70392e6433a6b8f" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers measured the punching — and spear-throwing — force of 20 men and 19 women. The assumption was that early humans were punchers <em>and</em> spear-throwers.</p><p>Prior to testing, each participant had filled out an activity questionnaire so that "we weren't getting couch potatoes, we were getting people that were very fit and active," says Morris.</p><p>For punching, participants operated a hand crank that required movement similar to throwing a haymaker. The purpose of the hand crank was to spare participants any damage that might be inflicted on their fists by throwing actual punches. Subjects were also measured pulling a line forward over their heads to assess their strength at throwing a spear.</p><p>Even though all of the participants, male and female, were routinely fit, the average power of males was assessed as being 162% greater than females. There were no gender differences in throwing strength recorded. Other untested, though presumably likely, hand-to-hand combat activities come to mind including tackling, clubbing, running, kicking, scratching, and biting.</p><p>Carrier's takeaway: "This is a dramatic example of sexual dimorphism that's consistent with males becoming more specialized for fighting, and males fighting in a particular way, which is throwing punches."</p>
Boys will be boys<p>It, er, strikes us as odd that, even in science fiction — hi-tech weaponry notwithstanding — the hero <em>is</em> going to wind up duking it out with some bad guy, or alien, in the climactic battle. What is it about men punching, anyway? Are they more sexually attractive? The study suggests so:</p><p style="margin-left: 20px;"><em>The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.</em></p><p>It's tough to contribute to the gene pool after being killed in battle.</p><p>Also, while the authors aren't <em>quite</em> saying that males' historical fighting role is mandated by biology and not by social expectations, neither are they quite <em>not</em> saying it.</p><p>As Carrier explain to <a href="https://attheu.utah.edu/facultystaff/carrier-punch/" target="_blank">theU</a>: "Human nature is also characterized by avoiding violence and finding ways to be cooperative and work together, to have empathy, to care for each other, right? There are two sides to who we are as a species. If our goal is to minimize all forms of violence in the future, then understanding our tendencies and what our nature really is, is going to help."</p>
The Labour Economics study suggests two potential reasons for the increase: corruption and increased capacity.
Cool hand rebuke<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTIyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjY1NTYyOH0.0MCPKN3If94mYCNf3mMNrnTvJXjXN_bKLhgk9203EXk/img.jpg?width=917&coordinates=0%2C0%2C0%2C0&height=453" id="1627b" class="rm-shortcode" data-rm-shortcode-id="6d76421ba1ea0de4b09956b97e80c384" data-rm-shortcode-name="rebelmouse-image" />
A chart showing prison population rates (per 100,000 people) in 2018. The United States has the highest rate of incarceration in the world.
Who profits with for-profit prisons?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="97ac37e6c7f6f22ec130ea2d56871701"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/dB78NV2WpWc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>The Labour Economics study suggests that privately-run prisons do convicts a few favors at the moment of sentencing. However, proponents of private prisons often point to other benefits when making their case. Specifically, they argue that private prisons reduce operating costs, stimulate innovation in the correctional system, and reduce recidivism—the rate at which released prisoners are rearrested and return to prison.</p><p>In regard to recidivism, the research is mixed. <a href="https://journals.sagepub.com/doi/abs/10.1177/0011128799045001002" target="_blank">One study</a> compared roughly 400 former prisoners from Florida, 200 released from private prisons and 200 from state-run facilities. It found the private-prison cohort maintained lower rates of recidivism. However, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1745-9133.2005.00006.x" target="_blank" rel="noopener noreferrer">another Florida study</a> found no significant rate differences. And two other studies—one from <a href="https://journals.sagepub.com/doi/abs/10.1177/0011128799045001002" target="_blank" rel="noopener noreferrer">Oklahoma</a> and another out of <a href="https://journals.sagepub.com/doi/abs/10.1177/0734016813478823" target="_blank" rel="noopener noreferrer">Minnesota</a>, both comparing much larger cohorts than the first Florida study— found that prisoners leaving private prisons had a greater risk of recidivism.</p><p>The research is also inconclusive regarding cost savings. <a href="https://www.hamiltonproject.org/assets/files/economics_of_private_prisons.pdf" target="_blank" rel="noopener noreferrer">A Hamilton Project analysis</a> noted that such comparisons are difficult because private prisons, like all private companies, are not required to release operational details. In comparing what studies were available, the authors estimate the costs to be comparable and that "in practice the primary mechanism for cost saving in private prisons is lower salaries for correctional officers"—about $7,000 less than their public peers. They add that competition-driven innovation is lacking as the three largest firms control nearly the entire market.</p><p>"We aren't saying private prisons are bad," Galinato said. "But states need to be careful with them. If your state has previous and regular issues with corruption, I wouldn't be surprised to see laws being more skewed to give longer sentences, for example. If the goal is to reduce the number of incarcerated individuals, increasing the number of private prisons may not be the way to go."</p>
What exactly does "questions are the new answers" mean?
- Traditionally, intelligence has been viewed as having all the answers. When it comes to being innovative and forward-thinking, it turns out that being able to ask the right questions is an equally valuable skill.
- The difference between the right and wrong questions is not simply in the level of difficulty. In this video, geobiologist Hope Jahren, journalist Warren Berger, experimental philosopher Jonathon Keats, and investor Tim Ferriss discuss the power of creativity and the merit in asking naive and even "dumb" questions.
- "Very often the dumb question that is sitting right there that no one seems to be asking is the smartest question you can ask," Ferriss says, adding that "not only is it the smartest, most incisive, but if you want to ask it and you're reasonably smart, I guarantee you there are other people who want to ask it but are just embarrassed to do so."