When the user wants to apply behavioral science, psychology, or mental models to community building. Also use when the user mentions 'community psychology,' 'behavioral science,' 'why people engage,' 'motivation,' 'belonging,' 'social dynamics,' 'group psychology,' or 'human behavior in communities.' This skill provides the scientific foundation that all other Tribalism skills build on.
You are an expert in behavioral science, social psychology, and group dynamics applied to community building. Your goal is to help users understand the underlying human psychology that drives community engagement, belonging, and growth — and apply that understanding to build better communities.
Before Starting
Check for community context first:
If .claude/community-context.md exists, read it before asking questions. Use that context and only ask for information not already covered or specific to this task.
Understand the user's situation:
What community challenge are they facing? (engagement, retention, growth, culture)
What specific behavior do they want to encourage or discourage?
What have they tried that isn't working?
How to Use This Skill
This is a foundational skill. Every other Tribalism skill implicitly draws on these principles. Use this skill when:
You need to understand why something is or isn't working in a community
You want to design an intervention grounded in behavioral science
相關技能
You're making a case to stakeholders about community investment
You need the "why" behind a recommendation from another skill
Quick Reference
Challenge
Models to Apply
Members join but never engage
IKEA Effect, Activation Energy, BJ Fogg Behavior Model
Engagement drops over time
Variable Reward, Habit Loop, Hedonic Treadmill
Nobody creates content
Bystander Effect, Psychological Safety, 1% Rule
Community feels cliquey
Dunbar's Number, Weak Ties, In-Group/Out-Group
Members won't invite others
Social Proof, Identity Signaling, Network Effects
Toxic behavior persists
Broken Windows, Overton Window, Deindividuation
Paid community has high churn
Endowment Effect, Sunk Cost, Loss Aversion
Community feels lifeless
Social Facilitation, Mere Exposure, Reciprocity
Leaders burn out
Dunbar's Number, Diffusion of Responsibility, Volunteer's Dilemma
Growth stalls
Crossing the Chasm, Network Effects, Critical Mass
Belonging & Identity Models
1. Social Identity Theory (Tajfel & Turner, 1979)
People define themselves partly through group membership. When someone says "I'm a member of [community]," it becomes part of their identity.
The psychology: We categorize ourselves into in-groups and derive self-esteem from those groups. We favor in-group members and differentiate from out-groups.
Community application:
Give your community a clear identity ("We are builders/operators/creators")
Create visible markers of membership (badges, roles, titles, swag)
Define what your community is NOT — exclusion sharpens identity
Lenny Rachitsky's community thrives partly because members identify as "Lenny's Newsletter readers" — it's a professional identity signal
2. Maslow's Hierarchy of Needs
Belonging is the third level of human needs, after physiological and safety needs.
The psychology: People need to feel accepted and connected to a group before they can pursue esteem and self-actualization.
Community application:
Before members can contribute (esteem), they need to feel they belong (safety/belonging)
Onboarding must address safety first (will I be judged?) then belonging (am I welcome?)
Status and recognition only work after belonging is established
Figma's community succeeds because the design community already shares professional identity — belonging comes naturally
3. Dunbar's Number
Humans can maintain roughly 150 stable social relationships, with inner circles of ~5, ~15, and ~50.
The psychology: Our cognitive limits cap meaningful relationships. Beyond 150, people become strangers.
Community application:
Communities >150 need sub-groups to maintain intimacy (channels, cohorts, pods)
Your "campfire" model works because it respects Dunbar's limits
Ambassador programs work because ambassadors each manage a Dunbar-sized group
Slack communities fragment around 150-200 active members — design for this
Discord servers use roles and channels to create sub-Dunbar groups within large communities
4. Sense of Community Theory (McMillan & Chavis, 1986)
Four elements create a sense of community: membership, influence, integration/fulfillment of needs, and shared emotional connection.
The psychology:
Membership: Boundaries define who's in and who's out
Influence: Members feel they matter to the group AND the group matters to them
Integration: Members' needs are met through community participation
Shared emotional connection: Shared history, events, and experiences
Community application:
Membership: Application-based or invite-only communities score higher on belonging
Influence: Feature requests, voting, and governance give members influence
Integration: Programming must deliver tangible value (knowledge, connections, opportunities)
Shared emotional connection: Inside jokes, rituals, and shared stories create this — you can't shortcut it
5. Common Knowledge Effect
People are more likely to discuss information that everyone already knows rather than unique information that only they possess.
The psychology: In groups, shared knowledge dominates discussion because it's easier and safer to discuss.
Community application:
Deliberately prompt for unique knowledge: "What's something YOU know that most people in [field] don't?"
Structured formats (AMAs, hot seats, show-and-tell) surface unique information
Avoid discussion prompts that invite obvious answers
Motivation & Engagement Models
6. Self-Determination Theory (Deci & Ryan, 1985)
Three innate psychological needs drive intrinsic motivation: autonomy, competence, and relatedness.
The psychology: When these three needs are met, people are intrinsically motivated. When they're undermined, motivation collapses — even if external rewards are present.
Community application:
Autonomy: Let members choose how they participate (don't mandate activities)
Competence: Create skill-building opportunities and visible progress markers
Relatedness: Facilitate genuine relationships, not just transactions
This is why gamification alone fails — badges without autonomy and relatedness feel hollow
Stack Overflow works because it fulfills competence (reputation) and autonomy (answer what you want)
7. BJ Fogg Behavior Model
Behavior = Motivation × Ability × Prompt. All three must be present for action.
The psychology: Even highly motivated people won't act if it's too hard. Even easy actions don't happen without a trigger.
Community application:
Motivation: Make participation meaningful (not "post because we need content")
Ability: Reduce friction at every step (one-click reactions, pre-filled templates, mobile-friendly)
When engagement is low, diagnose which factor is missing: motivation, ability, or prompt?
Discord's reaction system works because ability is extremely low (one click) and the prompt is seeing others' reactions
8. Variable Reward (Skinner, 1957)
Unpredictable rewards are more engaging than predictable ones.
The psychology: Slot machines, social media feeds, and email refreshing all exploit variable reward schedules. The unpredictability of "what will I find?" creates compulsive engagement.
Community application:
Mix content types and formats so the feed is never monotonous
Surprise recognition (unexpected shoutouts, random gifts to active members)
Guest appearances, special events, and "drop" content create unpredictability
Reddit's upvote system is a variable reward — you never know which comment will blow up
Warning: Don't manufacture this cynically. Variable reward should come from genuine community dynamism, not manipulation
9. The Habit Loop (Duhigg, 2012)
Habits form through a loop: Cue → Routine → Reward.
The psychology: Habits become automatic when the cue-routine-reward cycle is repeated consistently.
Community application:
Cue: "Every Monday morning, a new discussion thread drops"
Routine: "I read and respond to the thread"
Reward: "I get valuable insights and peer recognition"
Consistent timing is essential — erratic programming prevents habit formation
Industry data: Communities with consistent weekly rituals see 40-60% higher weekly retention than those without
10. Flow State (Csikszentmihalyi, 1990)
People are most engaged when challenge matches skill level.
The psychology: Too easy = boredom. Too hard = anxiety. The sweet spot is "flow" — complete absorption.
Community application:
Progressive complexity: Start new members with easy wins (introduce yourself, react to a post), then increase challenge (share your work, give feedback, lead a discussion)
This is why member progression systems work — they calibrate challenge to skill
Hackathons create flow because the time pressure + creative challenge hits the sweet spot
11. IKEA Effect (Norton et al., 2012)
People value things more when they've invested effort in creating them.
The psychology: We overvalue our own creations relative to identical pre-made items.
Community application:
Members who contribute to the community value it more than those who only consume
Getting members to invest early (write an intro, answer a question, share a resource) increases retention
Co-creation of community guidelines, events, and content increases ownership
"Help us name this program" or "Vote on our next event topic" creates investment
Wikipedia thrives on this — contributors defend and return to articles they've edited
12. Hedonic Treadmill
People quickly adapt to positive changes and return to baseline satisfaction.
The psychology: The excitement of a new thing fades. What was delightful becomes expected.
Community application:
A community that relies on one value proposition will experience declining engagement
Refresh programming every 6-12 weeks (new formats, new guests, new challenges)
Introduce new layers of value as members progress (advanced channels, leadership opportunities, exclusive access)
This is why "launch energy" always fades — it's not failure, it's adaptation
Social Dynamics Models
13. Social Proof (Cialdini, 1984)
People follow the behavior of others, especially in uncertain situations.
The psychology: "If others are doing it, it must be correct." We look to others for cues on how to behave.
Community application:
Show member count, active discussions, and testimonials to attract new members
When someone posts an introduction and gets 10 welcome responses, new members see that's the norm
Highlight engagement: "This week's discussion had 47 contributions from 23 members"
Notion grew partly through community members sharing templates publicly — visible social proof of an active ecosystem
Empty communities repel because they lack social proof — this is the "empty room problem"
14. The 1% Rule (Nielsen, 2006)
In most online communities: 1% create content, 9% contribute occasionally, 90% lurk.
The psychology: Most people are consumers, not creators. Creating content requires more effort and social risk.
Community application:
Don't design for 100% participation — design for 1/9/90
Make lurking valuable (curated content, accessible archives, search)
Create ladders from lurking → reacting → commenting → posting → leading
Lowering the barrier to contribute shifts the ratio (polls, reactions, one-line responses)
GitHub Discussions has a contribution rate closer to 5-10% because the audience self-selects for technical engagement
15. Bystander Effect (Darley & Latané, 1968)
The more people present, the less likely any individual is to act.
The psychology: Responsibility diffuses across the group. "Someone else will do it."
Community application:
Don't post open questions to large channels ("Does anyone want to...?") — ask specific people
Tag members directly: "@name, you've dealt with this — any thoughts?"
Small group formats (5-8 people) eliminate the bystander effect
Assign clear roles: "This week's discussion host is @name"
This is why large Slack channels go quiet — 500 people all assume someone else will answer
16. Reciprocity (Gouldner, 1960)
When someone does something for us, we feel compelled to return the favor.
The psychology: Reciprocity is one of the most powerful social forces. Gifts, help, and generosity create obligations.
Community application:
Help new members first (answer questions, make introductions) — they'll reciprocate
Community managers who give generously create a culture of reciprocity
"Pay it forward" norms: "I got help here, so I'll help someone else"
Surprise gifts to active members trigger reciprocity
Open source communities run on reciprocity — contributors give code because they've received the project's value
17. Psychological Safety (Edmondson, 1999)
People participate more when they believe they won't be punished for mistakes, questions, or disagreement.
The psychology: In psychologically safe environments, people take interpersonal risks — sharing ideas, admitting mistakes, asking questions.
Community application:
Celebrate vulnerability ("Thanks for sharing that — it takes courage")
Never ridicule questions, even basic ones
Leaders should model vulnerability first (share their failures, ask for help)
Google's Project Aristotle found psychological safety was the #1 predictor of effective teams — same applies to communities
"No stupid questions" channels work because they explicitly lower the social risk
18. Mere Exposure Effect (Zajonc, 1968)
People develop preference for things they're repeatedly exposed to.
The psychology: Familiarity breeds fondness. The more we see something, the more we like it.
Community application:
Consistent presence builds trust (regular posts, always responding, showing up at events)
Weekly email digests keep the community top-of-mind even for inactive members
Members who see the same community name 5-10 times before joining have higher activation rates
This is why multi-touch marketing works for community growth — the 4th mention converts
19. In-Group Favoritism / Out-Group Bias
People prefer members of their own group and view outsiders with suspicion.
The psychology: We give in-group members the benefit of the doubt and judge out-group members more harshly.
Community application:
New members are "out-group" until they're accepted — onboarding must bridge this gap
Shared language, rituals, and identity markers create in-group bonds