Logical fallacy #4: Ad populum

The ad populum fallacy can be summed up this way: 

“Come on, everybody’s doing it!”

The argument here is that you should do something simply because other people are. 

Definition: The Latin name of this fallacy means “to the people.” There are several versions of the ad populum fallacy, but what they all have in common is that in them, the arguer takes advantage of the desire most people have to be liked and to fit in with others and uses that desire to try to get the audience to accept his or her argument. One of the most common versions is the bandwagon fallacy, in which the arguer tries to convince the audience to do or believe something because everyone else (supposedly) does.

 

Examples: Pennélope reminds us of "The famous 'mom saying': If everyone is throwing themselves from a precipice, will you do it too?" This saying points out the clear problem with this type of thinking. She also comments, "Just because everyone eats at McDonald's doesn't mean it's healthy for you." The argument here would something like, "You should eat at McDonalds--it must be good for you, because everyone eats there and they aren't dead of heart disease..."

 

Tip: Make sure that you aren’t recommending that your readers believe your conclusion because everyone else believes it, all the cool people believe it, people will like you better if you believe it, and so forth. Keep in mind that the popular opinion is not always the right one.

(Credit: The Writing Center, University of North Carolina at Chapel Hill)