Hi everyone. My name is Jordan Mackenzie and I'm a graduate student

at the University of North Carolina at Chapel Hill.

I'm going to talk to you today about a type of informal fallacy

known as the argumentum ad populum fallacy or the Appeal to the People Fallacy.

Now let's start with a walk down memory lane.

Do you remember ever trying to cajole your parents into buying you the latest fad toy, say a Furby

by whining about how everyone at school thought that Furbies were the best toy ever

so they must really be the best toy ever.

Your parents probably responded by saying something like:

"If everyone at school jumped off a cliff, would you jump off a cliff?"

Your parents were, in fact, calling you out for making an appeal to the people

and for reasons that will become clear as you watch this video, they were perfectly right to do so.

Let's take a closer look at how this fallacy works.

An appeal to the people tries to establish the truth of some claim "P"

on the basis that a lot of people believe P to be true.

Because it is an informal fallacy, rather than a formal fallacy,

we know that there is something wrong with its content rather than its form.

In this case, the content that the argument provides in support of its conclusion simply isn't sufficient

or even necessarily relevant to establishing the truth of that conclusion.

An example will help clarify things.

Suppose you and your friend are arguing over whether or not Justin Bieber has any musical talent.

Your friend says, "Of course he has musical talent!

Millions upon millions of fans can't possibly be wrong!"

If you wanted to formalize your friend's argument, it would look something like this:

Premise 1): Millions of people think Justin Bieber has musical talent.

Conclusion: Therefore, Justin Bieber has musical talent.

Now, if you think there's something fishy about this argument, you're right.

The big problem with this argument is that it tries to establish the truth of its conclusion

that is, that Justin Bieber has musical talent,

by appealing to the fact that many people believe that conclusion to be true.

But this simply doesn't follow.

Something can be true, even if everyone believes it to be false.

And something can be false, even if everyone believes it to be true.

Now, I don't mean to say that we should always completely disregard popular opinion

when we're trying to figure out whether or not something is true or false.

Often, the fact that most people believe in the truth of some claim

does actually give us at least some reason to think that that claim really is true.

If, for example, you find out that 98% of your sociology class

thought that the answer to question five on the exam was "C,"

it would be reasonable for you to think that "C" probably was indeed the right answer.

After all, if they all managed to arrive at that answer,

it was probably because they properly studied for the test.

You would be committing a fallacy, however, if you thought that the answer to question five

was "C" BECAUSE 98% of your sociology class had answered the question that way.

So, while popular support may give you a reason to BELIEVE a claim to be true

It is very rarely, itself, the thing that MAKES that claim true.

Note that I said "very rarely" and not "never."

In fact, there are a few cases in which Appeals to Popularity are NOT fallacious.

Consider etiquette: if I am trying to argue that it is rude in India to leave one's shoes on indoors

it is very reasonable for me to appeal to the fact that most people in India

think that it's rude to leave one's shoes on indoors.

In this case, the content to which I am appealing,

that is, the opinions of the Indian population,

is completely relevant to the conclusion that I am trying to establish.

Or, suppose that you are having an argument with a friend about how this letter is pronounced in Canadian English.

Here's a situation where there would be nothing wrong about making an argument like,

"Almost everyone in Canada says 'zed'

so the correct pronunciation in Canadian English must be 'zed' and not 'zee.'

Keep in mind, however, that these examples are the exceptions and not the rule.

Most of the time it's a good idea to be suspicious of arguments

that attempt to establish the truth of the conclusion by appealing to popular opinion.