Which fallacy argues that because everyone is doing something, you should do it too?

• A. Bandwagon
• B. Ad hominem
• C. False dichotomy
• D. Hasty generalization

Answer: (A)

The idea tested is the bandwagon fallacy: using popularity as the reason to act. It persuades you to do something simply because many people are doing it, implying that the action must be correct or beneficial just because it’s popular. In reasoning terms, quantity of people isn’t evidence of quality or truth, so basing a decision on what most people do is a faulty justification. Social proof can be informative in some contexts, but it doesn’t substitute for evaluating the actual reasons, costs, and benefits of the action.

For example, if everyone switches to a particular app because their friends did, you might be influenced to switch too, even if it doesn’t meet your needs or has hidden downsides. That’s the bandwagon at work—appeal to what others are doing rather than a solid argument or evidence.

Understanding this helps you spot when an argument leans on popularity instead of facts. The other common fallacies differ: ad hominem attacks the person rather than the argument; false dichotomy presents only two options; hasty generalization draws a broad conclusion from a small or biased sample.