Defining Dunbar’s Number
The evolutionary psychologist Robin Dunbar identified that an average person’s social network appears to follow simple scaling laws.
Our networks grow from our closest friends—whom we would seek personal advice or help from in times of severe emotional and financial distress—through our superfamily (or close friends), to our acquaintances (or clan), whom we might invite to a party, and to our most casual friends (or tribe).
Dunbar’s Number is a theoretical cognitive limit to the number of stable social relationships a person can maintain. Proposed by British anthropologist Robin Dunbar, this number is approximately 150. It represents the maximum number of individuals with whom one can maintain meaningful, reciprocal relationships, where you know who each person is and how they relate to every other person in the group.
The Science Behind Dunbar’s Number
Cognitive Limitation: Dunbar’s research suggests that the size of the human neocortex (the part of the brain responsible for conscious thought and language) limits our ability to manage larger social networks.
Layered Relationships: Dunbar also identified layers of relationships within the 150:
5: Close friends or family (innermost circle).
15: Good friends (people you trust and rely on).
50: Friends (people you know well and socialize with).
150: Meaningful connections (people you recognize and maintain some level of interaction with).
Role of Dunbar’s Number in Making Meaningful Connections
Quality Over Quantity: Dunbar’s Number emphasizes that meaningful relationships require time, effort, and emotional investment. It’s not about how many people you know but how deeply you connect with them.
Social Stability: Maintaining a network within this limit helps create a stable social environment, reducing stress and increasing emotional support.
Trust and Reciprocity: Relationships within this number are based on mutual trust and reciprocity, which are essential for long-term bonds.
Community Building: Dunbar’s Number explains why smaller communities or teams (e.g., villages, startups, or military units) often function more cohesively than larger groups.
Why Dunbar’s Number Matters in Modern Life
In an age of social media and constant connectivity, Dunbar’s Number reminds us that human relationships thrive on depth, not breadth.
It encourages us to focus on the people who truly matter, fostering a sense of belonging and emotional well-being.
Connections of Dunbar’s number with my life and Other Examples.
I read it in the book Midnight Library, where the protagonist is seeks meaningful connection in my life.
I would always ask this question back in college when I would want to open up to them, “Are they in my top 50?”
Malcolm Gladwell discusses the Dunbar number in his 2000 book The Tipping Point. In the company Gore-Tex brand, by trial and error, the leadership in the company discovered that if more than 150 employees were working together in one building, different social problems could occur. The company started building company buildings with a limit of 150 employees and only 150 parking spaces. When the parking spaces were filled, the company would build another 150-employee building. Sometimes these buildings would be placed only short distances apart.
The number has been used in the study of virtual communities, especially MMORPGs, such as Ultima Online, and social networking websites, such as Facebook (Dunbar himself did a study on Facebook in 2010) and MySpace.
The Swedish Tax Agency planned to reorganise its functions in 2007 with a maximum 150 employees per office, referring to Dunbar's research.
In 2007, Cracked.com editor David Wong wrote a humour piece titled "What is the Monkeysphere?" explaining Dunbar's number and its implications. In his 2012 novel This Book Is Full of Spiders, the character Marconi explains to David the effect Dunbar's number has on human society. In Marconi's explanation, the limit Dunbar's number imposes on the individual explains phenomena such as racism and xenophobia, as well as apathy towards the suffering of peoples outside of an individual's community.
In a piece for the Financial Times (10 August 2018) titled "Why drink is the secret to humanity's success", Dunbar mentioned two more numbers: an inner core of about 5 people to whom we devote about 40 percent of our available social time and 10 more people to whom we devote another 20 percent. All in all, we devote about two-thirds of our time to just 15 people.
How to Apply Dunbar’s Number in Life Practically
1. Prioritize Your Inner Circle
Focus on nurturing relationships with the 5-15 people who matter most to you (close family and friends).
Example: Schedule regular catch-ups, celebrate milestones, and offer support during tough times.
2. Be Intentional About Your Social Network
Recognize that you can’t maintain deep connections with everyone. Allocate your time and energy wisely.
Example: Instead of trying to stay in touch with hundreds of acquaintances, invest in relationships that bring you joy and fulfillment.
3. Use Dunbar’s Layers to Organize Relationships
Categorize your relationships into layers (5, 15, 50, 150) to understand where to focus your efforts.
Example: Your closest 5 might be your immediate family, while the next 15 could include close friends and mentors.
4. Leverage Technology Mindfully
Social media can make it seem like you have hundreds of "friends," but Dunbar’s Number reminds us to focus on meaningful interactions.
Example: Use platforms like WhatsApp or Facebook to stay connected with your 150, but prioritize face-to-face or one-on-one communication for your inner circles.
5. Build Strong Communities
Whether at work, in your neighborhood, or in social groups, aim to create a sense of belonging within a group of around 150.
Example: If you’re leading a team or organization, keep it small enough to foster trust and collaboration.
6. Let Go of Superficial Connections
Accept that it’s okay to let go of relationships that no longer serve you or align with your values.
Example: If you’re feeling overwhelmed by too many social obligations, politely step back from less meaningful connections.
7. Apply It to Professional Networks
In your career, focus on building strong relationships with a core group of colleagues, mentors, and collaborators.
Example: Instead of networking with hundreds of people at events, aim to build deeper connections with a select few who share your professional goals.
8. Teach It to Others
Share the concept of Dunbar’s Number with friends, family, or colleagues to help them understand the importance of meaningful connections.
Example: Use it as a conversation starter about how to build stronger, more fulfilling relationships.
Source Illustrations for my Zettels
