12 Logical Fallacies Used as Tools of Persuasion
Logical fallacies are errors in reasoning that weaken an argument. But they also have the power to short-cut or bypass a listener’s critical thinking – which is why they can be used intentionally to persuade and manipulate people an audience.
Some people are really good at doing this – the Ancient Greeks called them sophists. Today’s sophists often use a combination of social media and AI to amplify their persuasion techniques and reach a mass audience.
Here are 12 logical fallacies that can show up today as tools of persuasion, along with tips for how to defend against them.
1. Straw Man
What it is:
When someone twists or exaggerates their opponent ’s argument into something that’s easier to attack. Instead of arguing what that person actually said, they’re arguing against a distorted version of it.
How it can be used to persuade:
Someone can make the other side sound ridiculous or extreme so you’re less likely to take that argument seriously. “She wants students to have less homework? Apparently, she doesn’t think kids should have to work at all.”
The defence:
Go back to what the person actually said. Ask yourself: Is this a fair description of their argument – or has it been exaggerated or twisted into something easier to attack?
2. Ad Hominem (Personal Attack)
What it is:
Attacking the person instead of dealing with their argument. This can involve mocking their appearance, intelligence, personality, politics or past behaviour.
How it can be used to persuade:
Someone can try to make you dislike, distrust or laugh at a person so you become less willing to listen to what that person is saying.
The defence:
Mentally remove the insult and look at the argument that remains. Ask yourself: Does anything said about this person actually prove their argument wrong?
3. Poisoning the Well
What it is:
Trying to discredit a person, source or argument before anyone has the chance to judge their argument for themselves.
How it can be used to persuade:
Someone can plant doubt or suspicion in your mind before you encounter the other side. For instance, someone online might introduce a clip by saying, “Wait until you hear what this so-called expert says,” or share an article with “Of course the media wants you to believe this.” Even if what follows is reasonable or well-supported, you may already be primed to distrust it.
The defence:
Notice when someone is telling you what to think about a person or source before you’ve heard what they actually have to say. Set that framing aside and judge their opinion and evidence for yourself.
4. False Dilemma (Either/Or)
What it is:
Presenting only two choices when other possibilities exist.
How it can be used to persuade:
Someone can make their preferred choice look like the only acceptable one – because the other choice they have presented is intentionally unreasonable. “Either you support this new law or you want anarchy.” It forces the audience to choose between a seemingly reasonable option and an intentionally exaggerated alternative.
The defence:
Don’t automatically accept the choices you’re given. Ask yourself: Are these really the only options, or are other possibilities being left out?
5. Appeal to Popularity (Bandwagon)
What it is:
Treating popularity as evidence that something is true, good or worth doing.
How it can be used to persuade:
Someone can make you afraid of being left out. Millions of views, thousands of likes, a sold-out product or a pile-on in the comments section can create powerful pressure to join in.
The defence:
Separate how many people believe something from whether there are good reasons to believe it. Popularity can tell you what has caught on, but not whether it’s true, wise or right.
6. Appeal to Authority
What it is:
Treating someone’s status, fame or expertise as enough to prove a claim.
How it can be used to persuade:
Someone can use their credibility or status in one area to sound authoritative in an area they know nothing about. Others can also then spread that claim, using that person’s status as proof of its accuracy.
The defence:
Check the authority, then check the evidence. Ask yourself: Does this person actually have expertise in this subject – and would the claim still be convincing if their famous name or credentials were removed?
7. Appeal to Emotion
What it is:
Using a strong emotion such as fear, anger, pity, pride, disgust or guilt to push people toward a conclusion without giving them enough reason to accept it.
How it can be used to persuade:
Someone can get you feeling before you start thinking. A frightening image, a heartbreaking story or rage-inducing video can make an argument feel true before you’ve examined it.
The defence:
Notice what you’re being made to feel before deciding what you think. Then ask yourself: If I took away the frightening image, sad music, outrage or guilt, what argument and evidence would be left?
8. Slippery Slope
What it is:
Claiming that one step will lead to a chain of increasingly extreme consequences without showing why that chain is likely.
How it can be used to persuade:
Someone can turn a small decision into a terrifying future. “If we allow this one change, pretty soon everything will be out of control.” The speed of the story can make the final disaster feel inevitable even when several uncertain steps are hiding in between.
The defence:
Slow the chain down. Ask yourself: Does each step actually make the next one likely, or am I being rushed from a reasonable possibility to an extreme conclusion?
9. Cherry-Picking
What it is:
Selecting the evidence – favourable stats, convenient quotations, dramatic clips – that supports a claim while leaving out evidence that complicates or contradicts it.
How it can be used to persuade:
For example: A creator can show you three studies that support their position while ignoring ten that don’t, post only the worst moments from someone’s interview or choose the dates on a graph that make a trend look dramatic. Everything you’re being shown might be real – the trick is in what you aren’t being shown.
The defence:
Ask what you aren’t being shown. Look for the full quotation, complete video, larger data set, original source or evidence that might point in another direction.
10. Appeal to Flattery
What it is:
Using praise or compliments to make someone more likely to accept a claim, agree to something or take a particular action.
How it can be used to persuade:
Online persuasion often makes agreeing feel like membership in a flattering category: “Smart people understand this.” “Only independent thinkers can see what’s really happening.” “If you’re one of the few people who actually thinks for yourself, keep watching.” Suddenly rejecting the message can feel like admitting you’re gullible, ordinary or uninformed.
The defence:
Remove the compliment and see what’s left. Ask yourself: Would this argument still persuade me if nobody were making me feel clever, special or admired for agreeing with it?
11. Scapegoat Fallacy
What it is:
Blaming one person or group for a complicated problem while ignoring other important causes or contributing factors.
How it can be used to persuade:
A post or video can take a complicated problem – such as high prices, crime, unemployment, struggling schools – and give you one group to blame for it. Memes and short videos are especially good at turning “This is one factor” into “These people are the reason this is happening.”
The defence:
Be suspicious when a complicated problem is given one convenient villain. Ask yourself: What other causes or factors might be contributing to this and is this person or group really responsible for as much as I’m being told?
12. Appeal to Tradition
What it is:
Arguing that something is better, right or should continue simply because it has been done or believed for a long time.
How it can be used to persuade:
You might see posts comparing the present unfavourably with an idealized past: “Kids never needed this before.” “People have eaten this for centuries.” “This is how families have always worked.” The long history of something can make it seem automatically safer, wiser or better.
The defence:
Respect tradition without treating age as proof. Ask: Why did this tradition begin, does that reason still apply and is there good reason to keep it now?
There are many more logical fallacies and ways to persuade people. Check back to this section for subsequent articles.