Home › Ideas › Science › Learn about Dunbar's Number

Learn about Dunbar's Number

⏱️ 10-15 minutes 📊 Beginner 🔬 Science

About This Idea

Discover why humans can only maintain about 150 meaningful relationships—a cognitive limit rooted in our evolutionary past. This quick lesson explains why social media's thousands of 'friends' don't align with how our brains actually work.

#psychology#anthropology#social-networks#evolution#cognition

📑 Table of Contents

How to Get Started

STEP 1
THE DISCOVERY (3 minutes)
  1. British anthropologist Robin Dunbar studied primate social groups
  2. Found correlation between brain size and social group size
  3. Predicted humans can maintain ~150 stable relationships
  4. This became known as 'Dunbar's Number'
  5. Not friends - but people you could ask a favor from without it being weird
STEP 2
THE LAYERS (5 minutes)
  1. Relationships form concentric circles:
  2. - 5 people: closest confidants (family/best friends)
  3. - 15 people: good friends (regular contact)
  4. - 50 people: friends (monthly contact)
  5. - 150 people: meaningful connections (could ask for help)
  6. - 500 people: acquaintances (recognize)
  7. - 1500 people: can put a face to a name
  8. Each layer takes time and cognitive energy to maintain
  9. Moving someone from outer to inner layer requires sustained investment
STEP 3
WHY THE LIMIT? (4 minutes)
  1. Your neocortex (brain region for social processing) has limits
  2. Tracking relationships requires remembering:
  3. - Person's history and context
  4. - Your history with them
  5. - Their relationships with others
  6. - Social norms and obligations
  7. - Emotional states and patterns
  8. This cognitive load maxes out around 150 people
  9. Hunter-gatherer tribes averaged ~150 members
  10. Military companies traditionally ~150 soldiers
  11. Successful companies often split departments at ~150 people
STEP 4
IMPLICATIONS FOR MODERN LIFE (3 minutes)
  1. Facebook friends, Instagram followers don't change brain capacity
  2. You're still limited to ~150 meaningful relationships
  3. Social media creates illusion of more connections
  4. But 'friends' beyond 150 are shallow - you can't maintain them properly
  5. Quality vs quantity matters more than we think
  6. Your brain evolved for tribal life, not global social networks

What You'll Need

Recommended Resources

📚 Tutorials & Learning

  • Dunbar's Number Research 🔗
    New Yorker article
  • Social Brain Hypothesis 🔗
    Video explanation

👥 Communities

  • r/psychology 🔗
    Psychology discussion
  • r/anthropology 🔗
    Human evolution and society

Progress Milestones

Track your progress with these key achievements:

1
5 minutes
Understand Dunbar's Number
2
10 minutes
Grasp relationship layers
3
15 minutes
Apply to modern social media

Common Challenges & Solutions

Every beginner faces obstacles. Here's how to overcome them:

⚠️ I have way more than 150 Facebook friends!
Solution: Test this: Could you comfortably ask each of them for a favor? Have a meaningful conversation? Remember details about their life? Most 'friends' are actually acquaintances.

Share Your Progress

Celebrate your achievements and inspire others:

Ready to Get Started?

Discover more creative ideas and start your next adventure!

Get Today's Idea

You Might Also Like

Understand what causes déjà vu

Explore the neuroscience behind that eerie feeling of 'I've experienced this before.' Learn how your brain accidentally stores short-term memories directly into long-term storage, making new experiences feel strangely familiar.

beginner 10-12 minutes

Discover the Mandela Effect

Explore the fascinating phenomenon where large groups of people share identical false memories. Named after people who wrongly remembered Nelson Mandela dying in prison in the 1980s, this cognitive quirk reveals how our memories are reconstructed rather than recorded.

beginner 10-15 minutes

Discover octopuses' 9 brains

Learn about one of nature's most extraordinary cognitive systems: octopuses have a central brain plus one in each of their eight arms, allowing independent problem-solving. This quick dive into marine biology reveals an alien intelligence right here on Earth.

beginner 8-12 minutes

Share This Idea

Help others discover this creative project!

Link copied to clipboard! ✨