Bandwagon is a fallacy based on the assumption that the opinion of the majority is always valid: that is, everyone believes it, so you should too. It is also called an appeal to popularity, the authority of the many, and argumentum ad populum (Latin for “appeal to the people”). Argumentum ad populum proves only that a belief is popular, not that it’s true. The fallacy occurs, says Alex Michalos in Principles of Logic, when the appeal is offered in place of a convincing argument for the view in question.

Examples

• “Carling Lager, Britain’s Number One Lager” (advertising slogan)
• “The Steak Escape. Americas Favorite Cheesesteak” (advertising slogan)
• “[Margaret] Mitchell enhanced the GWTW [Gone With the Wind] mystique by never publishing another novel. But who would be so churlish as to want more? Read it. Ten million (and counting) Americans can’t be wrong, can they?” (John Sutherland, How to be Well Read. Random House, 2014)

Hasty Conclusions

“Appeals to popularity are basically hasty conclusion fallacies. The data concerning the popularity of the belief are simply not sufficient to warrant accepting the belief. The logical error in an appeal to popularity lies in its inflating the value of popularity as evidence.” (James Freeman [1995), quoted by Douglas Walton in Appeal to Popular Opinion. Penn State Press, 1999)

Majority Rules

“The majority opinion is valid most of the time. Most people believe that tigers do not make good household pets and that toddlers shouldn’t drive…Nonetheless, there are times when the majority opinion is not valid, and following the majority will set one off track. There was a time when everyone believed the world was flat and a more recent time when the majority condoned slavery. As we gather new information and our cultural values change, so too does the majority opinion. Therefore, even though the majority is often right, the fluctuation of the majority opinion implies that a logically valid conclusion cannot be based on the majority alone. Thus, even if the majority of the country did support going to war with Iraq, the majority opinion is not sufficient for determining whether the decision was correct.” (Robert J. Sternberg, Henry L. Roediger, and Diane F. Halpern, Critical Thinking in Psychology, Cambridge University Press, 2007)

“Everyone’s Doing It”

“The fact that ‘Everyone’s doing it’ is frequently appealed to as a reason why people feel morally justified in acting in less than ideal ways. This is particularly true in business matters, where competitive pressures often conspire to make perfectly upright conduct seem difficult if not impossible.

“The ‘Everyone’s doing it’ claim usually arises when we encounter a more or less prevalent form of behavior that is morally undesirable because it involves a practice that, on balance, causes harm people would like to avoid. Although it is rare that literally everyone else is engaged in this behavior, the ‘Everyone’s doing it’ claim is meaningfully made whenever a practice is widespread enough to make one’s own forbearing from this conduct seem pointless or needlessly self-destructive.” (Ronald M Green, “When Is ‘Everybody’s Doing It’ a Moral Justification?” ​Moral Issues in Business, 13th ed., edited by William H Shaw and Vincent Barry, Cengage, 2016)​

Presidents and Polls

“As George Stephanopoulos wrote in his memoir, Mr. [Dick] Morris lived by a ’60 percent’ rule: If 6 out of 10 Americans were in favor of something, Bill Clinton had to be, too…

“The nadir of Bill Clinton’s presidency was when he asked Dick Morris to poll on whether he should tell the truth about Monica Lewinsky. But by that point he had already turned the ideal of the presidency upside down, letting arithmetic trump integrity as he painted his policies, principles and even his family vacations by the numbers.” (Maureen Dowd, “Addiction to Addition,” The New York Times, April 3, 2002)