Crowd Behavior: Contagion, Convergence & Emergent Norm Theory

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Mass Hysteria & Moral Panic: Definitions, Causes & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 Crowd Behavior
  • 0:32 Contagion Theory
  • 2:36 Convergence Theory
  • 4:15 Emergent-Norm Theory
  • 5:31 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Juli Yelnick

Juli has traveled the world engaging in cultural immersion experiences that bring her Master of Liberal Studies findings to light.

Why do people act differently in crowds than they do individually? In this lesson, we will discuss three different theories to explain crowd behavior: contagion theory, convergence theory, and emergent norm theory.

Crowd Behavior

Crowds are common occurrences and can be seen in sporting events, music concerts, shopping sales, and amusement parks. Crowd behavior is the behavior that is conducted by individuals who gather in a crowd, while a crowd is defined as a gathering of people who share a purpose. There have been many theories developed to explain crowd behavior, and in this lesson, we will take a look at the contagion theory, convergent theory, and emergent norm theory in relation to crowd behavior.

Contagion Theory

Gustave Le Bon, a French social psychologist born in 1841, is considered to be the founder of crowd psychology, which explains why people do the things they do in groups. Le Bon's 1895 book, The Crowd: A Study of the Popular Mind, attributed crowd behavior to the 'collective racial unconscious' of the mob overtaking individuals' sense of self and personality and personal responsibility.

According to Le Bon, relieved of individual responsibility, individuals will behave in a more primal fashion. He asserts, 'by the mere fact that he forms part of an organized crowd, a man descends several rungs on the ladder of civilization.' A modern comparison might be the teenager who argues that his own actions of toilet papering the principal's house weren't so bad because everybody else was doing it too.

In his book, Le Bon also formulated the contagion theory, which argues that crowds cause people to act in a certain way. The theory suggests that crowds exert a sort of hypnotic influence on their members. The hypnotic influence combined with the anonymity of belonging to a large group of people, even just for that moment, results in irrational, emotionally charged behavior. Or, as the name implies, the frenzy of the crowd is somehow contagious, like a disease, and the contagion feeds upon itself, growing with time. In the end, the crowd has assumed a life of its own, stirring up emotions and driving people toward irrational, even violent action.

The 18th-century French Revolution is an example of how contagion theory can be used to explain crowd behavior. Exacerbated by hard economic times, famine, and resentment of the ruling class, crowds of peasants, farmers, and workers stormed the Bastille on July 14, 1789, with the intention of obtaining guns and killing the ruling class, including King Louis XVI.

Convergence Theory

Whereas the contagion theory states that crowds cause people to act in a certain way, convergence theory says the opposite. People who want to act in a certain way intentionally come together to form crowds. Convergence theory was formulated by many leading sociologists, and it assumes that when a critical mass of individuals with the same desire to affect change come together, collective action occurs almost automatically.

Think 'strength in numbers.' One person might believe strongly in a cause but assumes that his own individual action could not make a difference. As a result, individuals rarely act out alone. When they can convene with other individuals who have similar goals, the potential for successfully changing a policy or condition becomes more of a reality. With the support of others, an individual feels that the goal is within reach.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account