Group Behavior Online: How the Internet Transforms Collective Human Psychology
On January 28, 2021, the stock price of GameStop--a struggling brick-and-mortar video game retailer--surged from roughly $20 to nearly $500 per share. The surge was not driven by a change in the company's fundamentals. It was driven by a group of individual retail investors on the Reddit forum r/WallStreetBets who collectively decided to buy the stock, partly as an investment thesis, partly as an act of collective defiance against institutional hedge funds that had bet against the company through short selling. The result was one of the most dramatic demonstrations of online group behavior in history: millions of individuals, most of whom had never met each other, coordinated through a digital platform to move financial markets that were supposed to be dominated by trillion-dollar institutions.
The GameStop episode illustrates the central paradox of online group behavior: the same mechanisms that enable collective brilliance also enable collective madness. The coordination, information sharing, and mutual reinforcement that allowed retail investors to identify and execute a legitimate trading strategy also produced a speculative frenzy that cost some participants their life savings. The solidarity that united the group against institutional short sellers also created intense social pressure that discouraged selling even when individual rational analysis suggested it was prudent.
Online group behavior is not simply offline group behavior conducted through digital tools. The internet fundamentally transforms how groups form, how they communicate, how they make decisions, and how they act collectively. Understanding these transformations is essential for navigating a world in which online groups shape political movements, financial markets, cultural trends, corporate reputations, and individual lives.
How Does Group Behavior Differ Online?
Speed of Formation
Offline groups form slowly. Building a social movement, organizing a protest, or assembling a community of interest historically required physical meetings, printed materials, phone trees, and months or years of relationship building. Online groups can form in hours or minutes around shared interests, reactions to events, or algorithmic recommendation:
- A viral tweet can catalyze a group of millions within hours
- A Reddit post can organize collective action overnight
- A Discord server can grow from zero to thousands of active members within weeks
- A TikTok trend can mobilize coordinated behavior across millions of users within days
This speed of formation means that online groups often exist before they have developed the norms, leadership structures, and conflict resolution mechanisms that offline groups typically develop during slower formation processes. They are, in effect, groups without governance--powerful enough to act collectively but lacking the institutional structures to manage that collective power responsibly.
Scale Without Proximity
Offline groups are constrained by physical proximity. You can only be in the same room with so many people, and the logistics of assembling large groups physically are expensive and time-consuming. Online groups face no proximity constraint: a Reddit forum can have 13 million members across every continent, and all of them can participate in the same discussion simultaneously.
This scale creates qualitatively different dynamics:
- Extreme diversity of perspective: Large online groups contain perspectives that would never coexist in a single physical space, creating potential for both creative synthesis and destructive conflict
- Critical mass for niche interests: Online groups can aggregate people with obscure interests from across the world, creating communities that could never achieve critical mass locally
- Amplification effects: When millions of people can amplify a message simultaneously, even a small action by each individual (a like, a share, a retweet) can produce enormous aggregate effects
- Loss of individual significance: In a group of millions, each individual's contribution feels--and is--marginal, which reduces both the sense of personal responsibility and the sense of personal impact
Reduced Social Cues
Face-to-face group interaction provides rich social information: who is speaking, how they are feeling, whether the group agrees or disagrees, what the emotional temperature of the room is. Online group interaction strips away most of this information:
- Text-based communication removes tone, facial expression, and body language
- Asynchronous interaction means group members are not experiencing the discussion simultaneously
- Identity ambiguity means group members may not know who they are interacting with (anonymous accounts, bots, sockpuppets)
- Missing context means statements are interpreted without the background information that face-to-face acquaintance provides
The reduction of social cues has several consequences for group behavior:
- Misinterpretation increases: Without tonal cues, disagreements escalate more quickly because ambiguous statements are interpreted as hostile
- Empathy decreases: Without seeing the faces and bodies of other group members, empathic responses are weakened
- Social inhibition decreases: Without the presence of visible others, individuals are more willing to express extreme views, insult others, or engage in behavior they would avoid in physical groups
- Consensus is harder to read: In a physical room, you can sense whether the group agrees or disagrees. In an online forum, you cannot--which creates uncertainty that can be exploited by vocal minorities
Why Do Groups Polarize Online?
Group polarization--the tendency of groups to move toward more extreme positions than the average of their individual members' initial positions--is one of the best-documented phenomena in social psychology. Online environments amplify this tendency through several mechanisms.
Echo Chambers and Filter Bubbles
When people self-select into groups of like-minded individuals--and when algorithmic recommendation systems accelerate this self-selection by showing people more of what they already engage with--the result is echo chambers in which group members are primarily exposed to information and opinions that confirm their existing views:
- Confirmation bias operates at the group level: the group collectively seeks, shares, and amplifies information that supports its shared beliefs while ignoring or dismissing contradicting information
- Social proof creates apparent consensus: when all visible opinions in a group point in the same direction, each member's confidence in that direction increases, even when the apparent consensus results from selection effects rather than independent evaluation
- Extremity competition: Within ideologically homogeneous groups, members compete to demonstrate commitment to the shared position, ratcheting up extremity over time (a process sometimes called outbidding)
Visibility of Consensus
Online platforms make group opinions visible in ways that face-to-face groups cannot match:
- Upvotes, likes, and reaction counts quantify agreement
- Trending topics signal collective attention
- Follower counts signal influence
- Share and retweet counts signal endorsement
This visibility creates powerful conformity pressure: when a position has accumulated thousands of upvotes, disagreeing feels not just unpopular but objectively wrong. Dissenting voices self-censor, reducing the diversity of visible opinion and further strengthening the appearance of consensus. The result is a spiral of silence in which the most popular position becomes increasingly dominant, not because it is correct but because alternatives become increasingly invisible.
Out-Group Dynamics
Online groups define themselves partly by what they oppose. Political groups define themselves against opposing parties. Fan communities define themselves against rival fandoms. Identity groups define themselves against perceived adversaries.
This out-group dynamic is amplified online because:
- Opposing views are encountered primarily through curated, decontextualized examples selected to provoke outrage
- Out-group members are abstractions (usernames, avatars) rather than visible human beings
- Hostility toward the out-group is rewarded with in-group approval (likes, upvotes, social recognition)
- The distance and anonymity of online interaction reduce the social costs of expressing hostility
The result is tribal polarization: groups become increasingly cohesive internally and increasingly hostile externally, with each escalation of hostility by one group provoking reciprocal escalation by the other.
What Is Online Mob Behavior?
Online mobs are a distinctive form of collective behavior enabled by the speed, scale, and low coordination cost of digital communication. An online mob forms when a large number of people direct coordinated attention and action at a single target--typically an individual, sometimes an organization or institution.
How Mobs Form
Online mobs typically follow a recognizable pattern:
Triggering event: Someone does or says something that a group finds offensive, outrageous, or deserving of punishment. The trigger may be a genuine transgression, a misunderstood statement, fabricated outrage, or a resurface of old content.
Signal amplification: Influential accounts or platforms amplify the triggering event, exposing it to a much larger audience than the original context reached.
Emotional contagion: Outrage, disgust, or righteous anger spreads through the network as people react to the triggering event and to each other's reactions, creating escalating emotional intensity.
Participation cascade: The low cost of participation (writing a comment, sending a message, posting a screenshot) combines with social reward for participation (likes, agreement, in-group approval) to produce rapid growth in the number of participants.
Escalation: The mob's behavior escalates from criticism to insults to threats to real-world consequences (doxxing, contacting employers, harassment of family members).
Diffusion of responsibility: Each participant contributes only one small action (one tweet, one comment, one email), making it psychologically easy to participate and difficult to feel personally responsible for the aggregate impact.
The Asymmetry Problem
Online mob behavior creates a devastating asymmetry between the cost of participation and the cost of being targeted:
- For each mob participant, the cost is trivial: a few seconds typing a message that they will forget about within hours
- For the target, the cost is enormous: thousands of hostile messages, potential loss of employment, damage to reputation, threats to physical safety, lasting psychological trauma
This asymmetry means that the collective power of the mob vastly exceeds the sum of its individual members' intentions. Most mob participants do not intend to cause devastating harm to the target--they are expressing a momentary reaction that, individually, would be insignificant. But aggregated across thousands of participants, their individually trivial actions produce collectively devastating effects.
Mob vs. Movement
The distinction between an online mob and an online social movement is important but often blurred:
- Movements have goals, organization, strategy, and accountability structures. They seek systemic change and are willing to sustain effort over time.
- Mobs are reactive, unorganized, strategic only in the sense that they converge on a single target, and dissipate once the emotional intensity fades.
Many online collective actions contain elements of both: the initial response to a perceived injustice may have the character of a mob (rapid, emotional, focused on punishing an individual), while the broader movement it generates may have genuine organizational structure and systemic goals. The MeToo movement, for example, involved both mob-like targeting of specific individuals and movement-like advocacy for systemic change.
Online Groupthink: When Conformity Replaces Critical Thinking
Groupthink--a concept developed by psychologist Irving Janis to describe how cohesive groups make poor decisions by prioritizing consensus over critical analysis--is amplified in online environments.
How Online Groupthink Operates
Online groupthink manifests through specific mechanisms:
- Illusion of unanimity: Upvoting and algorithmic sorting make popular opinions hypervisible and dissenting opinions invisible, creating the impression that the group unanimously agrees when in fact dissent exists but is hidden
- Self-censorship: Group members who disagree with the prevailing position remain silent because the social cost of dissent (downvotes, hostile responses, potential banning or ostracism) exceeds the perceived benefit of speaking up
- Collective rationalization: The group develops increasingly elaborate explanations for why its position is correct and why contradicting evidence is unreliable, biased, or irrelevant
- Stereotyping of dissenters: Group members who do dissent are labeled as trolls, shills, concern trolls, or agents of the out-group, delegitimizing their dissent without engaging with its substance
- Mind guards: Influential group members actively police the boundaries of acceptable discourse, attacking or removing content that challenges the group's position
| Groupthink Symptom | Offline Manifestation | Online Amplification |
|---|---|---|
| Illusion of unanimity | Silence mistaken for agreement | Algorithmic sorting hides minority views |
| Self-censorship | Not speaking up in meetings | Not posting when downvotes or hostility are expected |
| Stereotyping dissenters | Dismissing colleagues as "not team players" | Labeling dissenters as trolls, bots, or agents |
| Collective rationalization | Group discussions reinforce shared narrative | Threads and chains build increasingly elaborate justifications |
| Pressure on dissenters | Social awkwardness, career risk | Downvotes, banning, doxxing, coordinated harassment |
Consequences of Online Groupthink
Online groupthink produces several harmful outcomes:
- Poor collective decisions: Groups that suppress dissent make worse decisions because they fail to consider alternatives, identify weaknesses, or anticipate problems
- Radicalization: Groups that exclude moderate voices and reward extreme positions progressively radicalize, moving toward positions that most individual members would reject if considering them independently
- Information failure: Groups that dismiss contradicting information become disconnected from reality, constructing shared narratives that are internally coherent but factually wrong
- Harmful collective action: Groups that combine poor decisions, radicalized positions, and disconnection from reality may take collective actions that cause real harm to themselves and others
Can Online Groups Coordinate Positively?
The same mechanisms that enable mobs and groupthink also enable remarkable positive coordination:
Knowledge Aggregation
Online groups can aggregate knowledge from thousands or millions of individuals to produce collective intelligence that exceeds any individual's capacity:
- Wikipedia: Millions of volunteer editors collaborate to maintain the world's largest encyclopedia, producing articles that research has shown are comparable in accuracy to professionally edited encyclopedias
- Stack Overflow: Millions of programmers share solutions to technical problems, creating a knowledge base that has become essential infrastructure for the global software industry
- Open-source software: Distributed groups of developers collaborate to produce software (Linux, Firefox, Python, WordPress) that rivals or exceeds commercial alternatives
- Citizen science: Online platforms enable thousands of non-expert volunteers to contribute to scientific research through data collection, classification, and analysis
Mutual Aid and Support
Online groups enable support networks that were previously impossible:
- Health communities: Patients with rare diseases connect with others who share their condition, sharing information, emotional support, and practical advice
- Crisis response: During natural disasters, online groups coordinate mutual aid (housing, supplies, transportation) faster than formal relief organizations
- Mental health support: Online peer support communities provide accessible help for people who cannot access or afford professional services
- Financial support: Crowdfunding platforms enable groups to aggregate small individual contributions into significant financial support for individuals in need
Social Movements
Online coordination has enabled social movements of unprecedented scale and speed:
- The Arab Spring (2011) used social media to coordinate protests across multiple countries
- The Black Lives Matter movement used online platforms to organize protests, share documentation of police violence, and mobilize political pressure
- Climate activism coordinated by groups like Fridays for Future mobilized millions of participants across dozens of countries through online organization
- LGBTQ+ rights movements have used online platforms to build community, share stories, and coordinate advocacy
How Do Leaders Emerge in Online Groups?
Leadership in online groups operates differently from offline leadership. Without formal organizational structures, leadership emerges informally through several mechanisms:
Early Participation
Individuals who participate in a group from its early stages often accumulate disproportionate influence simply by being present during the period when the group's norms, culture, and identity are being established. Early participants shape the group's character, and later participants adapt to the culture that early participants created.
Value Contribution
Individuals who consistently contribute high-value content--insightful analysis, useful information, skilled creative work, effective moderation--accumulate social capital that translates into informal leadership. Other group members defer to their judgment, amplify their contributions, and look to them for guidance.
Consistent Presence
Online communities are fluid, with most members participating sporadically. Individuals who are consistently present--posting regularly, responding to others, maintaining awareness of the group's ongoing discussions--accumulate influence through sheer availability.
Identity Alignment
Individuals whose expressed identity, values, and communication style align closely with the group's emerging identity become exemplars--living representations of what the group aspires to be. Other members look to them as models and defer to them as authorities on what the group stands for.
Platform Affordances
Platform design shapes leadership emergence:
- Moderator tools: Platforms that grant moderation powers to specific users create formal leadership positions within otherwise informal groups
- Visibility mechanisms: Algorithms that amplify content from users with more followers or higher engagement create Matthew effects (the rich get richer) that concentrate influence
- Verification and badges: Platform-granted markers of status (verified badges, special roles) create hierarchies that influence who is listened to and who is ignored
What Causes Online Groups to Fragment?
Online groups are inherently fragile. The low cost of exit (leaving a group requires nothing more than clicking a button or simply not returning) means that groups face constant pressure to maintain cohesion.
Common Causes of Fragmentation
- Norm conflicts: As groups grow, new members bring different expectations about acceptable behavior. When these expectations conflict with established norms--and when the conflict cannot be resolved through negotiation--the group may split.
- Leadership disputes: Without formal governance structures, disputes over who has authority and how decisions are made can become intractable, leading factions to break away.
- Ideological splits: As groups develop shared identities, disagreements about the core ideology (what the group believes, what it stands for, what it opposes) can produce schisms when factions develop irreconcilable interpretations.
- Platform changes: When the platform that hosts a group changes its features, policies, or algorithms, the group may fragment as members disagree about whether to adapt, migrate, or resist.
- Scale effects: Groups that grow beyond a certain size often lose the intimacy and shared identity that made them cohesive, leading smaller factions to break away in search of the community feel they have lost.
The Eternal September
One of the earliest documented patterns of online group fragmentation is Eternal September, named for the phenomenon observed on Usenet in September 1993 when AOL began providing Usenet access to its millions of subscribers. Each September, the arrival of new college freshmen with university internet access had temporarily disrupted Usenet's established culture, but the newcomers eventually assimilated to existing norms. When AOL opened the floodgates, the volume of newcomers was so large that they could not be assimilated--they simply overwhelmed the existing culture, fundamentally changing the character of the communities they entered.
This pattern--an influx of new members who do not share the founding culture overwhelming the established community--has repeated across virtually every online platform that has grown rapidly. The founding members of a subreddit, a Discord server, or a Facebook group often lament that the community "isn't what it used to be" as growth dilutes the shared culture that defined it.
How Can Online Group Behavior Be Improved?
Improving online group behavior requires understanding that group dynamics are shaped by the interaction of individual psychology, social dynamics, and platform design. Interventions at any of these levels can shift group behavior.
Platform Design
Platforms can design features that promote constructive group behavior:
- Friction: Adding small delays or requirements before posting (confirmation dialogs, cool-down periods) reduces impulsive behavior
- Diverse exposure: Algorithms that occasionally surface perspectives from outside the user's usual bubble can reduce echo chamber effects
- Accountability mechanisms: Persistent identity, reputation systems, and visible behavioral history create incentives for constructive behavior
- Moderation tools: Providing community moderators with effective tools for managing conflict, removing harmful content, and enforcing norms
- Scale management: Tools that help large groups subdivide into smaller, more cohesive subgroups can maintain community feel as membership grows
Community Governance
Groups can develop governance structures that manage collective behavior:
- Explicit norms: Written rules and expectations reduce ambiguity about acceptable behavior
- Distributed moderation: Engaging multiple community members in moderation spreads the burden and reduces the risk of moderator bias
- Conflict resolution processes: Established procedures for handling disputes prevent conflicts from escalating to fragmentation
- Onboarding: Deliberate introduction of new members to community norms and culture reduces the "Eternal September" problem
- Feedback mechanisms: Regular opportunities for members to provide input on community direction and governance reduce the sense of powerlessness that drives exit
Individual Awareness
Individuals who understand the psychological dynamics of online groups are better equipped to resist their destructive effects:
- Recognizing echo chamber effects and deliberately seeking out diverse perspectives
- Being aware of emotional contagion and pausing before contributing to escalating situations
- Understanding that perceived consensus in an online group may not reflect actual consensus
- Recognizing the diffusion of responsibility dynamic in mob situations and choosing not to participate
- Maintaining awareness that the people behind usernames are real human beings with complex lives and perspectives
The internet has given human beings unprecedented capacity for collective action. Whether that capacity is used for collective intelligence or collective foolishness, for mutual aid or coordinated cruelty, for social progress or mob destruction, depends on the design of the platforms, the governance of the communities, and the awareness and choices of the individuals who participate. None of these factors alone determines the outcome--the interaction of all three shapes the group behavior that emerges in any given online space.
References and Further Reading
Sunstein, C.R. (2017). #Republic: Divided Democracy in the Age of Social Media. Princeton University Press. https://en.wikipedia.org/wiki/Cass_Sunstein
Janis, I. (1982). Groupthink: Psychological Studies of Policy Decisions and Fiascoes. 2nd ed. Houghton Mifflin. https://en.wikipedia.org/wiki/Groupthink
Shirky, C. (2008). Here Comes Everybody: The Power of Organizing Without Organizations. Penguin Press. https://en.wikipedia.org/wiki/Here_Comes_Everybody
Ronson, J. (2015). So You've Been Publicly Shamed. Riverhead Books. https://en.wikipedia.org/wiki/So_You%27ve_Been_Publicly_Shamed
Benkler, Y. (2006). The Wealth of Networks: How Social Production Transforms Markets and Freedom. Yale University Press. https://en.wikipedia.org/wiki/The_Wealth_of_Networks
Postmes, T., Spears, R. & Lea, M. (2000). "The Formation of Group Norms in Computer-Mediated Communication." Human Communication Research, 26(3), 341-371. https://doi.org/10.1111/j.1468-2958.2000.tb00761.x
Noelle-Neumann, E. (1993). The Spiral of Silence: Public Opinion--Our Social Skin. 2nd ed. University of Chicago Press. https://en.wikipedia.org/wiki/Spiral_of_silence
Surowiecki, J. (2004). The Wisdom of Crowds. Doubleday. https://en.wikipedia.org/wiki/The_Wisdom_of_Crowds
Tufekci, Z. (2017). Twitter and Tear Gas: The Power and Fragility of Networked Protest. Yale University Press. https://en.wikipedia.org/wiki/Twitter_and_Tear_Gas
Phillips, W. (2015). This Is Why We Can't Have Nice Things: Mapping the Relationship Between Online Trolling and Mainstream Culture. MIT Press. https://mitpress.mit.edu/9780262529877/this-is-why-we-cant-have-nice-things/
Bail, C. (2021). Breaking the Social Media Prism: How to Make Our Platforms Less Polarizing. Princeton University Press. https://press.princeton.edu/books/hardcover/9780691203423/breaking-the-social-media-prism
Zuboff, S. (2019). The Age of Surveillance Capitalism. PublicAffairs. https://en.wikipedia.org/wiki/The_Age_of_Surveillance_Capitalism
Rheingold, H. (2000). The Virtual Community: Homesteading on the Electronic Frontier. Revised ed. MIT Press. https://en.wikipedia.org/wiki/The_Virtual_Community