You're surfing the web, maybe arguing with friends online, and someone drops a seemingly logical point. But something feels off. Could it be a post hoc fallacy in disguise? You've come to the right place to find out.
A Post Hoc Fallacy occurs when someone mistakenly assumes that because one event follows another, the first event caused the second.
By the end of this article, you'll be a pro at spotting this fallacy in everyday life and conversations. Equipped with a wealth of examples, the psychology behind it, and its historical background, you'll not only understand what a post hoc fallacy is but also how to avoid falling for it.
What is a Post Hoc Fallacy?
Imagine you're walking outside, and you find a lucky penny on the ground. Later that day, assume you ace a test. You might think, "Hey, that penny must have brought me good luck." That's a post hoc fallacy. You're connecting two events in time and assuming the first one caused the second.
The term Post Hoc Fallacy is a shortened form of "Post Hoc, Ergo Propter Hoc," a Latin phrase meaning "After this, therefore because of this." It's a way of thinking that can lead you astray, making you connect dots that shouldn't be connected.
Post hoc fallacies are a type of logical fallacy that tries to find causal relationships between two unrelated events without adequate evidence. Fallacies are logical errors, usually in arguments, that people make which lead to inconsistent reasoning.
Finding an accurate causal connection can be really important details for things like science and medicine.
Imagine pseudoscientific arguments (that's a fancy way of saying something does not follow proper scientific methods) that try to say one thing caused another, and thus we create a medical treatment based on it without enough evidence. This magical thinking could actually harm people.
Other Names for This Fallacy
- Post Hoc Rationalization
- Post Hoc Reasoning
- Post Hoc Ergo Propter Hoc
- Causal Fallacy
- Faulty Causality
Similar Logical Fallacies
- Slippery Slope - Arguing that one event will inevitably lead to a series of other events.
- Appeal to Ignorance - Assuming something is true because it hasn't been proven false.
- Circular Reasoning - Using the conclusion as the premise, basically arguing in a circle.
- Red Herring - Introducing an irrelevant topic to divert attention from the original issue.
The concept of the post hoc fallacy has been around for a long time, but it got its formal name from the field of philosophy. The term itself is Latin and has been used in academic circles to discuss flawed arguments.
The phrase "Post Hoc, Ergo Propter Hoc" was coined to specifically identify this type of logical misstep. Although the name might sound fancy, the concept is pretty simple: It warns us not to mistake sequence for causation.
27 Examples
1) Sports Superstitions
"I wore my lucky jersey, and my team won the game. The jersey must be why they won."
Here, the assumption is that wearing a specific jersey caused the team to win. It mistakes coincidence for causality, which is the essence of the post hoc fallacy.
2) Weather and Aches
"Every time it rains, my knee aches. The rain must cause my knee to hurt."
Although it's common to hear people say this, there is no scientific evidence linking rainfall directly to joint pain. It's a classic example of a post hoc fallacy.
3) Organic Food and Health
"I started eating organic food, and now I never get sick. Organic food must be the reason I stay healthy."
While eating organic food might be part of a healthy lifestyle, attributing your entire well-being to it is a post hoc fallacy.
4) Economic Booms
"Every time this political party is in power, the economy booms. They must be good for the economy."
Correlation does not mean causation. Economic cycles are influenced by many factors and attributing it to a single cause is a post hoc fallacy.
5) Lunar Moods
"People act weird when there's a full moon, so the moon must influence behavior."
Despite popular belief, no reliable studies prove that the full moon has any significant effect on human behavior. This claim is another post hoc fallacy.
6) Emotional Support Animals
"I was feeling depressed, but since getting a dog, I've been happier. My dog must have cured my depression."
While pets can provide emotional support, stating that they cure depression oversimplifies a complex mental health issue and is an example of post hoc reasoning.
7) The Ice Cream and Drowning Fallacy
"As ice cream sales increase, so do drownings. Therefore, eating ice cream must cause drownings."
This one is often cited as a textbook post hoc fallacy. Both ice cream sales and drownings increase in summer, but one doesn't cause the other.
8) Hollywood Divorces
"Since more Hollywood stars get divorced, fame must lead to failed marriages."
Divorce happens for numerous reasons, and assuming that fame is the singular cause oversimplifies the issue and is a post hoc fallacy.
9) Breakfast and Success
"Successful people eat breakfast; therefore, eating breakfast leads to success."
While having breakfast might be part of a balanced lifestyle, attributing all your future success to it is a post hoc fallacy.
10) Natural Disasters and Morality
"Since we've strayed from traditional values, natural disasters have increased. Our immorality must be causing these disasters."
Linking natural disasters to human morality is an ancient but still prevalent form of the post hoc fallacy.
11) Lucky Charms
"I passed my exam after carrying my lucky charm, so it must be a magical object."
Attributing success to an object just because you had it with you during the event is a classic example of post hoc reasoning.
12) New Coach, New Wins
"The team started winning after we got a new coach, so he must be the reason we're winning."
While a new coach can bring positive changes, attributing all success to this one change is an example of post hoc fallacy.
13) Changing Hair Color
"I dyed my hair and started getting more attention. Changing my hair color must make me more attractive."
Correlation doesn't imply causation. Getting more attention could be due to a variety of reasons, not just a change in hair color.
14) Studying Techniques
"I used a new studying technique and got a higher grade on my next test. This technique must be superior."
Even though the new technique may have helped, attributing your entire grade improvement to it is a post hoc fallacy.
15) Unemployment Rates
"Whenever this mayor is in office, unemployment rates drop. He must be good for job growth."
Many factors can influence unemployment rates; attributing it solely to a mayor's influence is a post hoc fallacy.
16) Meditation and Stress
"I started meditating and now feel less stressed. Meditation must be the only effective way to reduce stress."
While meditation can help reduce stress, saying it's the only effective way to do so is a post hoc fallacy.
17) Night Owls and Intelligence
"People who stay up late tend to be more creative. Therefore, being a night owl makes you creative."
This faulty causation is another classic post hoc fallacy, confusing correlation for causation.
18) Day Trading Luck
"I read the finance news this morning and made a profitable trade. Reading the news must make me a better trader."
One successful trade doesn't prove that reading financial news always leads to trading success. It's a post hoc fallacy.
19) Childhood Vaccines
"My child got vaccinated and then was diagnosed with a learning disorder. Vaccines must have caused the disorder."
This false claim lacks scientific evidence and falls under the category of post hoc fallacy.
20) Spicy Food and Longevity
"People in countries that consume a lot of spicy food live longer. Spicy food must increase longevity."
Longevity is influenced by multiple factors, and attributing it solely to spicy food is a post hoc fallacy.
21) Technology and Social Isolation
"Since the rise of smartphones, people have become more socially isolated. Smartphones must be causing social isolation."
Many factors contribute to social isolation. Blaming it solely on smartphones is a post hoc fallacy.
22) Wind Turbines and Health
"People living near wind turbines report more health issues. Therefore, wind turbines must be causing health problems."
Correlation does not mean causation, making this conclusion another example of post hoc fallacy.
23) Job Promotion
"I bought a new suit and then got a job promotion. My new suit must have led to my promotion."
Attributing a promotion to a new suit overlooks the various other factors that contribute to career advancement.
24) Acupuncture and Pain
"I tried acupuncture and my pain went away. Acupuncture must be the reason."
While acupuncture might have helped alleviate the pain, attributing complete relief solely to it is a post hoc fallacy.
25) Self-Help Books
"I read a self-help book and my life improved. The book must have all the answers I need."
Though self-help books can be beneficial, assuming they are the sole reason for life improvements is a post hoc fallacy.
26) Cutting Out Sugar
"I stopped eating sugar and lost weight. Cutting out sugar must be the only way to lose weight."
While cutting out sugar may help in weight loss, saying it's the only way is another example of a post hoc fallacy.
27) Video Games and Violence
"Violent incidents have increased since the rise of video games. Video games must be causing violence."
This is a frequently debated topic, but linking violent behavior solely to video games is a post hoc fallacy.
The Psychological Mechanisms Behind It
The post hoc fallacy often taps into our natural desire for simple explanations. Your brain loves shortcuts; it's wired to find patterns and make quick judgments. This is part of what psychologists call "heuristics," which are mental shortcuts that speed up decision-making.
However, these shortcuts can sometimes lead us astray, making us connect dots that shouldn't be connected.
Another underlying factor is "confirmation bias." This is when you have a tendency to search for, interpret, and remember information in a way that confirms your pre-existing beliefs.
So if you already believe that your lucky jersey helps your team win, every win that happens while you're wearing it seems to "confirm" that belief. In reality, you're falling for a post hoc fallacy, misattributing success to something that likely had no effect.
The Impact of the Post Hoc Fallacy
The post hoc fallacy might seem harmless on the surface, but its impact can be significant and far-reaching.
In personal relationships, it can foster misunderstandings and perpetuate myths. For example, if you believe that your partner's bad mood is always triggered by something you've done, you might change your behavior unnecessarily, complicating the relationship dynamics.
In broader contexts like science, politics, or healthcare, the stakes are even higher. Misattributing causes can lead to wrong conclusions, ineffective solutions, and wasted resources.
Imagine a policy implemented based on post hoc faulty reasoning alone; it would be like building a house on a shaky foundation. The chances of that policy actually solving the problem it's intended to address are low, and it might even make things worse.
How to Identify and Counter It
Spotting a post hoc fallacy starts with a healthy dose of skepticism. Whenever you hear a claim that one thing causes another, ask for the supporting evidence. Correlation does not imply causation; just because two events occur together doesn't mean one caused the other. Scrutinize the argument and look for other potential factors that might explain the outcome.
To counter a post hoc fallacy, bring these alternative explanations into the discussion. Use logic and evidence to dismantle the fallacious argument. In some cases, statistical data can be your best ally, showing that the supposed cause and effect aren't as closely related as they seem.
Another effective approach is to use counterexamples that defy the original claim, thus breaking down the simplistic cause-and-effect causal relationship that the post hoc fallacy tries to establish.
