What Is Ad Populum Fallacy? | Examples & Definition

The ad populum fallacy, also known as the appeal to popularity, is the mistake of arguing that a claim is true based solely on the fact that many people believe it. This fallacy appeals to innate biases that encourage us to conform to others’ opinions and behaviors.

Ad populum fallacy example
The Cardiff Giant, a 10-foot-tall “petrified man” statue discovered in New York in 1869, was said to be a petrified prehistoric giant. Many people believed in its authenticity solely due to its widespread popularity. However, the giant was revealed to be a carving created as a deliberate hoax.

This example of ad populum reasoning underscores how popularity alone can lead to the acceptance of a claim without sufficient evidence.

Ad populum arguments are often used to distract from a lack of substantial evidence for a claim. Examples can be found in many domains, including discussions of health, politics, and investment strategies.

What is ad populum fallacy?

The ad populum fallacy is the mistake of considering the popularity of a claim as proof that it is true. The fallacy’s full Latin name is argumentum ad populum, which means “argument to the people.”

Popularity alone can’t prove that a claim is true. A claim might be widely accepted because of cultural beliefs, social conformity, or misinformation. For example, historical misconceptions or myths, such as the idea that Napoleon Bonaparte was extremely short, often gain widespread acceptance even though they don’t reflect historical truth.

However, in contexts where the perspective of the majority holds significance—such as in market dynamics, cultural norms, linguistic practices, or establishing scientific consensus—it is reasonable to consider prevalent opinions.

Ad populum is an informal logical fallacy, meaning that it is a content-level error that renders an inductive argument unsound.

There are several cognitive biases that are closely related to the ad populum fallacy, all of which describe the human tendency to rely on popularity or consensus as a basis for decision-making:

  • Bandwagon effect: The tendency to adopt behaviors or beliefs because others are currently doing the same, with the assumption that popularity implies correctness
  • Social proof bias: The habit of relying on the behavior and opinions of others as a guide for one’s own actions and beliefs, especially when many people believe or do something
  • Conformity bias: The inclination to adjust one’s behavior or beliefs to align with those of a group or majority, often without critical evaluation

When is an ad populum argument legitimate?

Ad populum specifically refers to a logical fallacy, so in the strict sense of the term, an ad populum argument can’t be legitimate. However, there are contexts in which the popularity of a viewpoint or practice may be relevant to an argument, including the following examples:

  • Public opinion and policy: Leaders often weigh public opinion in creating policies.
  • Market research and product development: Companies use consumer preferences to shape products.
  • Language and communication: Linguists analyze common usage in language studies.
  • Social behavior and norms: Sociologists study widely accepted norms for insights into societal values and behaviors.
  • Scientific consensus: Scientists consider the majority views of experts in their fields, who have based their views on empirical evidence and rigorous analysis.

In contexts like these, it may be legitimate to support an argument with evidence of prevailing views. This is distinct from the ad populum fallacy, which relies solely on popularity as a basis for argumentation, often when popular opinion isn’t relevant at all.

What are different types of ad populum fallacies?

There are several specific types of ad populum fallacies, with the following being the best-known:

Bandwagon fallacy

The bandwagon fallacy is a specific type of appeal to popularity that focuses on a current trend. It’s the mistake of arguing that something is good or true because a growing number of people support it. The term “bandwagon” is also used to name a cognitive bias (the bandwagon effect) and propaganda technique (the bandwagon appeal).

Bandwagon fallacies are often quite effective because they take advantage of the human tendency toward social conformity and the desire for acceptance. People may join a movement or adopt a trend based on the group they wish to identify with and “jump on the bandwagon” even without sufficient knowledge. The bandwagon fallacy can also exploit the fear of missing out on an opportunity that others are enjoying.

Bandwagon fallacy example
In the 17th century, the Netherlands experienced a phenomenon that is now known as Tulip Mania. As tulip bulbs surged in popularity, they became an object of speculative trading, and their prices increased astronomically. The belief in tulip bulbs’ ever-increasing value was rooted in their popularity, with many arguing that their prices would only continue to rise. However, when the bubble burst, it left many investors in financial ruin.

The widespread belief in the tulips’ value among speculators was mistaken for evidence of their worth as an investment; thus, Tulip Mania serves as a classic example of bandwagon reasoning.

Appeal to common practice

The appeal to common practice fallacy makes the mistake of arguing that a behavior or course of action is correct because it’s common.

Appeal to common practice example
“Many politicians accept campaign donations from special interest groups, so it’s fine if our candidate does the same.”

Appeal to tradition

The appeal to tradition fallacy is the error of asserting that a claim or practice is good or true simply because it has been accepted historically.

Appeal to tradition fallacy example
“Our country has always had a monarchy, and that’s part of our national heritage, so we should maintain the monarchy even if there are better forms of government.”

Ad populum fallacy examples

Examples of the ad populum fallacy can be encountered in domains such as politics, advertising, social media, and religious discourse, whenever popularity is used as a basis for an argument without sufficient evidence or reasoning.

Ad populum fallacy in advertising
Ad populum reasoning often appears in advertising that appeals to the sales or reviews of a product to prove its value.

Statements like “9 out of 10 people prefer our brand” use popularity to imply quality, suggesting that a product is superior because many people choose it, without arguing its merits.

On social media, examples of the ad populum fallacy can often be found when engagement levels are misconstrued as indicators of truth.

Ad populum fallacy on social media
A conservative-leaning Facebook page asks its followers if the country should adopt stricter immigration controls to improve the economy. The majority of responses favor stricter controls, prompting the page to post, “The people have spoken: Stronger borders are what this country needs to prosper economically.”

In this example of the ad populum fallacy, the majority opinion among a small segment of the population is portrayed as definitive proof that stricter immigration controls would benefit the economy, without any concrete evidence.

Frequently asked questions about ad populum fallacy

How does the ad populum fallacy work?

The ad populum fallacy asserts that a claim is true solely because it’s popular. This fallacy typically occurs in an argument that disregards the need for evidence or sound reasoning, relying instead on the human tendency to conform to prevailing opinions.

What is an example of the ad populum fallacy in politics?

In politics, the ad populum fallacy can compel conformity through either desire (e.g., the desire to belong to the winning party) or fear (e.g., the fear of the stigma of supporting an unpopular candidate).

One historical example of ad populum reasoning is the Red Scare phenomenon in the United States. During periods of strong anti-communist sentiment in the twentieth century, many United States citizens were accused of being communists, often based on accusations without any other evidence. The fear of communism and the pressure to conform to anti-communist sentiments led to snowballing accusations and blacklisting

What is the difference between the ad populum fallacy and the appeal to authority fallacy?

Ad populum fallacies and appeal to authority fallacies both rely on people’s opinions to persuade, but there is a key difference:

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Magedah Shabo

Magedah is the author of Rhetoric, Logic, & Argumentation and Techniques of Propaganda and Persuasion. She began her career in the educational publishing industry and has over 15 years of experience as a writer and editor. Her books have been used in high school and university classrooms across the US, including courses at Harvard and Johns Hopkins. She has taught ESL from elementary through college levels.