Let's talk about Dunbar's number.
🤔 Why you should care about it
"British anthropologist Robin Dunbar theorised that a typical person can't easily have more than 150 people in his tribe. After 150 friends and fellow citizens, we can't keep track. It's too complicated." - Seth Godin, American author, in Linchpin.
According to British anthropologist Robin Dunbar, the maximum number of social relationships a human can effectively manage is 5 for close friends, 15 for good friends or teammates, 50 for casual friends and colleagues and 150 for communities with a very high incentive to remain together.
In the context of organisations, Dunbar's number has been used as a reference point to help understand the size and structure of teams and their potential impact on team dynamics and communication.
Communication breakdowns —> team members that cannot build close relationships with each other spend too much time communicating or finding the right person within the organisation.
Decreased performance —> coordination becomes vastly more challenging as organisations grow, creating decreased performance even if individuals give their best at their level.
Team member dissatisfaction —> team members' satisfaction and engagement are highly correlated with the ability to have meaningful relationships with colleagues.
Leveraging Dunbar's numbers to size teams, leaders should aim at having:
- Teams of 4 to 8 people that work together daily on a common goal (the infamous two-pizza team);
- Groups (or tribes) of 10 to 20 people that collaborate to achieve common objectives;
- Departments of 40 to 60 people coordinate to deliver a common strategy;
- Organisations of 140 to 160 people that work together to accomplish a joint mission;
Above 150 people, organisations should have different purposes and limit interactions altogether.
💡 Key Concepts
Social network structure —> human social networks have a structure, with individuals having different relationships with others in their network.
Community building —> the process of creating and maintaining a sense of belonging and connectedness among a group.
Social group sizing —> the process of determining the appropriate size of a social group based on the number of individuals with whom they can effectively maintain stable social relationships.
"The Dunbar numbers are artificial cognitive limitations that depends vastly on people and environments." —> while the numbers may not be a strict limit, it helps to have a theoretical framework for organisational design. In practice, teams could be more significant if need be.
"Technology, effective communication tools, processes, and more mitigate Dunbar's cognitive limits." —> while technology can help to improve communication and collaboration within groups, it may also introduce new challenges and difficulties, such as information overload and decreased face-to-face interaction.
"Being small is not the biggest predicator of a team's success." —> this is correct; the most significant predictor of a team's success is having a leader with the necessary skills, authority, and prior experience to assemble and oversee a team dedicated to reaching its objectives.
📚 Top book
🗂 See also
📝 Top content
Dunbar's Number and Team Size - Psychological Safety
Sizing engineering teams - Will Larson