Stuff You Should Know

Episode: How Crowds Work

Hosts: Josh Clark & Chuck Bryant
Release Date: February 17, 2026

Episode Overview

In this episode, Josh and Chuck delve into the dynamics of human crowds, exploring the science—physics, psychology, sociology—behind how people behave in group settings. They analyze notorious tragedies, expose persistent myths around “crowd madness,” and highlight the fascinating, often surprisingly prosocial nature of people when gathered en masse. The episode blends memorable real-world examples, amusing asides, and scientific insights to illuminate the complexities (and the underlying order) in crowd behavior.

Key Discussion Points & Insights

1. Defining a Crowd

• A Crowd Can Be Any Grouping:
  • “A crowd is any group of people temporarily gathered in the same physical space, relatively close to each other.” – Chuck (02:27)
  • Examples range from elevator passengers to millions at the Hajj pilgrimage. Purpose can be shared or accidental.
  • “Sometimes it’s on purpose. Sometimes it’s not planned by that person, but it just happens.” – Josh (02:44)

2. Common Fears and Misconceptions

• Crowds Feel Dangerous, but Are Typically Orderly:
  • “You might be a little scared of crowds, but that is sort of outdated thinking… the modern understanding… is that people are generally pretty orderly, even in the face of disaster.” – Chuck (03:33)
  • Historic tendency to blame crowds for tragedies; often, poor management or authority actions are true causes.

3. Tragedies: The Nightmare Side of Crowds

• Notable Crowd Disasters:
  • Astroworld Festival 2021 (Houston)
  • Coronation of Tsar Nicholas II (Moscow, 1896)
  • Love Parade tunnel crush (Duisburg, Germany, 2010)
  • Hajj pilgrimage catastrophes (2015, 1990)
  • “It seems like it will happen all the time because it’s just so shocking… but… it’s just not the case.” – Josh (05:21)
  • Physics of a “crowd crush”: bottlenecks and pressure from behind cause fatalities.
  • “Pressure can reach a thousand pounds of force, which is a lot…” – Chuck (05:44)

4. Studying Crowd Dynamics: Science at Work

• Fields Involved: Physics, physiology, psychology, systems theory.
  • “The movement and the formation of crowds resemble it [physics] so much that you can basically use physics terms like orbital motion or oscillators…” – Josh (08:51)
• Systems Theory & Fluid Dynamics:
  • “Lines of communication develop without speech… it becomes a cohesive whole…” – Josh (09:43)
• Social Force Model:
  • Unconscious, instinctive navigation keeps collisions rare.
  • “You just unconsciously, instinctively navigate without, like, constantly bumping into other people.” – Chuck (09:43–10:20)
• Lane Formation & Orbiting:
  • Spontaneous “lanes” form in moving crowds; “orbiting” occurs in dense, stationary crowds (e.g., Running of the Bulls).
  • “You complete this orbit in about 18 seconds…” – Josh (13:46)
• Density Danger Zones:
  • 2 people/sq. meter: still some room
  • 4: bumping starts
  • 6: movement very difficult (~1700 people on one tennis court)
  • 10: no individual movement, high risk of tragedy
  • “At 10 people per square meter… something bad is likely to happen.” – Chuck (15:00)

5. Crowd Psychology: How Minds Change in Groups

• Historic Theories:
  • Gustave Le Bon’s “Study of the Popular Mind” (1895) influential but now outdated.
    • Crowds as “mindless,” easily suggestible mobs—now known to be the extreme exception.
• Main Theories Discussed:
  • Contagion Theory: Emotional/behavioral “virus” spreads through crowds.
  • Convergence Theory: Crowds formed by similar people, so collective mind arises.
  • Group Mind Theory: Individual identity lost to group identity.
  • Social Identity Theory: Most accepted now—people adopt group behaviors/norms, but not mindlessly.
  • “Social identity theory seems to be the prevalent dominant view…” – Josh (20:39)

Key Concepts (22:32–25:13)

• Deindividuation:

  • “There’s this new social identity and your individual identity is taking a break.” – Chuck (22:48)
  • Classic experiments (Zimbardo’s prison study) illustrated this loss of personal identity in groups, for good or ill.
  • “You feel anonymous… connected to those other people… If those other people start… looting… you would probably never loot by yourself, but since you’re in that group… let’s get to it.” – Josh (23:51)

• Emotional Contagion:

  • Emotional states ripple through crowds, elevating shared feelings (good or bad).
  • “One person… triggers something because they’re extra emo and all of a sudden everyone rises to meet that level of emotion.” – Chuck (25:55)
  • Can be positive (dancing at Burning Man) or negative (escalating unrest).

• Suggestibility:

  • More pronounced when a charismatic leader is present; rare, but can redirect a group (Le Bon’s classic worry).
  • “You could tell them whatever and they’ll go do it… but it requires a central leader.” – Josh (28:49)
    • Notably exploited by Hitler, Mussolini, who read Le Bon.

6. Managing Crowds: Lessons & Best Practices

• Law Enforcement’s Critical Role:

  • “Instead we want law enforcement to do it… the best practices that… cut down the chance of a crowd turning ugly by huge percentages.” – Josh (04:29)
  • The mere presence of heavily armored police can escalate tensions and provoke violence.
    • “Just the presence of a law enforcement… in riot gear makes it more likely that a crowd will turn violent.” – Josh (31:14)

• Dialogue Teams:

  • European model—front-line officers engage and communicate calmly, rather than confront.
  • “You get your nicest cop, I guess… and make them the public facing face… and apparently it works a lot better…” – Chuck (31:51)
  • U.S. adoption is slow but growing, spurred by research and European precedent.

• Training is Critical:

  • Lack of officer training is a major factor in disasters (e.g., Sheffield soccer tragedy).
  • “The key to any… peaceful situation… is these cops have to be trained—like super trained. Training is the key…” – Chuck (33:35)

7. Crowds in Emergency: Myths Vs. Reality

• Collective Pro-Social Behavior:
  • Studies of disasters and emergencies consistently find that people help one another.
  • “If that subway breaks down, those strangers become a group almost instantly… to come together as a group, help one another, start to actually care…” – Josh (35:19)
• Bystander Effect is Overblown:
  • Recent studies of real fights showed most involved at least one, often multiple, interventions.
  • “The bystander effect says… the less likely anyone is to act to help. They found the opposite was true…” – Josh (39:00)
• Pluralistic Ignorance:
  • People wrongly assume their feelings are unique in a crowd, leading to silence or inaction in meetings/discussions.
  • “That’s called pluralistic ignorance, where you feel like even though your opinions differ, you are making an assumption about the rest of the group…” – Josh (40:17)

8. Protest & Violence: The Facts vs. The Hype

• Most Protests Stay Peaceful:

  • E.g., of 553 pro-Palestine campus protests (April–May 2024), 97% were “overwhelmingly peaceful.”
  • Of 2,400 BLM demonstrations after George Floyd’s murder, 93% had no violence.
  • “News doesn’t cover 2,400 peaceful protests. They cover the ones… you know.” – Chuck (41:49)

• Other Triggers for Disorder:

  • Weapons in crowds, and high alcohol consumption, both major catalysts for violence and riots.
  • “You’re not going to set a couch on fire in the street normally. But if you’re drunk and you’re part of a crowd whose basketball team just lost...” – Josh (42:39)

Memorable Quotes & Moments

• “People behave differently in crowds, and sometimes it’s great… I never dance like this, man, but I’m at Burning Man and look at me all of a sudden.” – Chuck (05:04)
• “That’s the quantum explanation of swerving.” – Josh (11:26)
• “I like that idea.” – Chuck, in response to “Does electron repulsion explain personal space?” (11:25)
• “[The crowd is] balancing on the razor’s edge at that point. It’s a really dangerous place to be.” – Josh, on ultra-dense crowds (16:18)
• “It’s not just the ecstasy speaking, friend. That is you being part of a crowd…” – Josh (24:45)
• “I think this is all just very fascinating.” – Chuck (25:13)
• “You used to hang out in a mosh pit or two back in the day, I’m sure…” – Chuck (26:32)
• Amusing detour: legendary Lollapalooza trash whirlpool during a mosh pit (27:41–28:10)

Key Timestamps for Major Segments

| Timestamp | Segment/Topic | |-----------|--------------| | 00:49–02:44 | Defining a crowd; initial examples | | 03:33–04:29 | Addressing crowd fears; “Orderly, not mindless” crowds | | 05:21–08:07 | Tragedies and crowd crush physics | | 08:51–11:26 | Physics/fluid dynamics of crowds, “social force” | | 12:12–13:57 | Lane formation & orbital motion in crowds | | 14:32–16:18 | Density thresholds and risks | | 17:34–22:48 | The psychology of crowds: Le Bon, historical theories | | 22:48–25:13 | Deindividuation: individual to group identity | | 25:13–27:14 | Emotional contagion; positive/negative ripple effects | | 28:35–29:55 | Suggestibility & manipulation | | 31:14–33:11 | Managing crowds: law enforcement’s role, dialogue teams | | 34:09–36:40 | Emergency situations; pro-social group behaviors | | 39:00–40:32 | Bystander effect and pluralistic ignorance debunked | | 41:29–41:54 | Protests and violence: the statistics | | 42:39–43:35 | Triggers for crowd violence: weapons, alcohol |

Final Thoughts

This episode offers an entertaining, myth-busting tour through crowd science—from highly organized, instinctive behaviors (like lane formation) to the tragic mechanics of crowd crushes and beyond. The hosts stress that panicky, violent crowds are rare exceptions, not the rule. Most of the time, humans in crowds are collaborative, adaptive, and resilient—even in emergencies. Law enforcement and event planners are learning to leverage these insights, moving from “control” to “dialogue.”

As the guys say:

• “Crowds can be dangerous, but they’re not inherently so. People, even among strangers, often rise to help and protect each other.”

Listener Takeaway:
Crowds are more orderly and prosocial than pop culture and sensational reporting suggest. Understanding and respecting the innate “social physics” of crowds can save lives, foster safety, and even inspire joy.