How to Persuade a Crowd

by Leon Tong

In our line of work creating digital platforms for very large audiences, it is important to understand how groups of people interact and engage.

This means researching and answering questions such as:

  • Why do people join groups?
  • What motivates a group or team?
  • What drives a group to take action?

Academics and scholars have been writing about these questions for many centuries. Fields such as social psychology, evolutionary biology and organisational behaviour provide answers from different but overlapping perspectives.

The Era of the Crowd

In 1895, the French social psychologist Gustave Le Bon, published La Psychologie des Foules—translated into English a year later as: The Crowd: A Study of the Popular Mind.

He wrote at a time which he christened “The Era of the Crowd”. Up until the 19th century, power had resided with an elite minoritybut this was beginning to change. Indeed in his native France, the fallout from the revolution of 1789 had not yet settled. However, he argued that the crowd was, on balance, not a force for good. He also described how groups are influenced and persuaded.

“…the special characteristics of crowds are several— impulsiveness, irritability, incapacity to reason, the absence of judgment…”

La Psychologie des Foules, Chapter II, The immediate factors of the opinions of crowds, Part 1.

The interesting aspect is that many of the techniques described in his book are used in marketing, advertising and political campaigns to this very day. Indeed it is well documented that a number of influential figures in the 20th century studied Le Bon in depth. Next time you read or watch an advertisement or listen to a political broadcast see if you can spot any of these following techniques.

Techniques to Persuade the Masses

“When, it is proposed to imbue the mind of a crowd with ideas and beliefs—leaders have recourse to different expedients—affirmation, repetition, and contagion. Their action is slow but very lasting. ”

Chapter III, The leaders of crowds and their means of persuasion, Part 2.

The main techniques to persuade a crowd are:

  1. affirmation
  2. repetition
  3. contagion
  4. exaggeration
  5. symbols
  6. ill-defined words
  7. but not reasoning or logic


“Affirmation… free of all reasoning and proof, is one of the surest means of making an idea enter the mind of crowds… the more destitute of proof and demonstration, the more weight it carries.”

Chapter III, The leaders of crowds and their means of persuasion, Part 2.

Affirmation — the declaration that something is trueis a tool employed extensively by leaders of crowds. This is true for religion, politics, finance, commerce and possibly every other field that deals with mass communication. One never hears “This might be the best product on the market”it is presented concisely as fact, or rather as a “truth”: “Ours is the number one product on the market”.

And note that affirmationkept free of all reasoning and all proofwill make an idea enter the minds of crowds. To persuade a crowd, one does not need (lengthy) proof or explanation. Save that for your one-to-one debate.

Crowds want clear and simple “truths”.


Affirmation, however, has no real influence unless it is constantly repeated, and so far as possible in the same terms. It was Napoleon who said that there is only one figure in rhetoric of serious importance, namely, repetition.

The thing affirmed comes by repetition to fix itself in the mind in such a way that it is accepted in the end as a demonstrated truth.

“…the repeated statement is embedded in the long run in those profound regions of our unconscious selves in which the motives of our actions are forged.”

Chapter III, The leaders of crowds and their means of persuasion, Part 2.

The “mad men” of advertising have long known the power of repetition. This psychological principle is precisely what makes advertising so successfulrepeat the same message often enough and before long it has entered a part of the brain that incites action. And what is more, the brain will recall the message as a “truth” or “fact” because it can no longer remember otherwise!


“Contagion is so powerful that it forces upon individuals not only certain opinions but certain modes of feeling as well…”

Chapter III, The leaders of crowds and their means of persuasion, Part 2.

Contagion occurs when repetition begins to spread widely across the group: ”It is by examples not by arguments that crowds are guided”. Therefore for contagion to occur the meme needs to be easily demonstrated and easily replicated.

This is what powers memes and viral marketing. Digital technology only assists and enhances a basic principle that is deeply hard-wired within our brains. From fashion to fads and mass political movements, contagion is the pinnacle that many communicators are searching for.

Even in Le Bon’s time it was not necessary for individuals of the group/crowd to be physically in the same place for contagion to occur. He cited the example of the Paris revolution of 1848 which spread across Europe and disrupted many a monarchy.

This has far-reaching benefits for digital communication. The most fundamental and powerful principles for persuading a crowd are not only assisted but accelerated by digital technology.


“…Given to exaggeration in its feelings, a crowd is only impressed by excessive sentiments. An orator wishing to move a crowd must make an abusive use of violent affirmations.”

Chapter II, The immediate factors of the opinions of crowds, Part 2.

No crowd wants to hear “Our idea is slightly better than the others” or “This car goes a little bit faster”. Crowds want to hear extremes and excesses. They are motivated and excited by it.

Exaggerationexcessive sentiments and affirmationsmay be slightly off-putting to the individual, but it is what sways the crowd. Almost every famous orator has put this technique to good effect: from Emmeline Pankhurst’s “Freedom or Death to Mahatma Gandhi’s “There is no salvation for India”, from Churchill’s “I have nothing to offer but blood, toil, tears and sweat” to John F. Kennedy’s “A new frontier” and Martin Luther King’s “I have a dream”.

All used bold, excessive sentiments to inspire and persuade the crowd.


“When studying the imagination of crowds we saw that it is particularly open to the impressions produced by images… They cause the birth in the minds of crowds of the most formidable tempests”

Chapter II, The immediate factors of the opinions of crowds, Part 1.

Since time immemorial, the leaders of crowds have recognised the power of symbols. Every major religion uses symbols to communicate. The Roman Empire was especially fond of symbols—and this has been replicated through the ages by many aspiring empire builders.

The modern-day empires that use symbols to great effect are the big global brands. These multinational companies are richer than many countries in the world.

National flags and symbols of pride evoke extreme emotiongood and bad. Symbolslogos, branding, clothing, accessoriesare also indicators of a particular “in-group”. If you want to be part of “our group” you need to dress like us, talk like us, and use the same products.

It is through a process of affirmation, repetition, and contagion that these symbols take on a greater meaning.

Ill-defined words

“Words whose sense is the most ill-defined are sometimes those that possess the most influence. They synthesise the most diverse unconscious aspirations and the hope of their realisation.”

Chapter II, The immediate factors of the opinions of crowds, Part 1.

Simon Sinek’s “Start with why?” is a great TED talk which explains the distinction between “how” words and “why” words perfectly. But when talking to many, the choice of words you use impacts how influential you are. Words which are more conceptual and vaguewhat Le Bon called “ill-defined”are the very words which convey the greatest influence.

Not reasoning or logic

“Reason and arguments are incapable of combatting certain words and formulas…”

Chapter II, The immediate factors of the opinions of crowds, Part 1.

So the final point seems obvious once explained but initially is so counter-intuitive! Why would I not try and persuade the whole organisation with my well-reasoned reasoning and logic?

But this logic is lost on the crowd.

What they want is simple, emotive statements.


Next time you listen to a public figure speaksee if you can identify any of the tools Le Bon wrote about. Do they use exaggeration, affirmation or repetition? Or analyse famous speeches from the past. Also look at how branding and advertising use LeBon’s techniques.

These principles are not just centuries old but go back millennia. These principles continue to apply to digital and software design.

Technology is not primarily what defines how we interact it. It is our very hard-wired brains that define which technology succeeds.

If you are looking for clues as to what makes a successful digital platform the psychology of the crowd is a good place to start…

Further Reading: