Dunbar's Number: The Science of Social Connections

What is Dunbar's Number?

Dunbar's Number suggests that humans can maintain stable social relationships with approximately 150 people. This cognitive limit was proposed by British anthropologist Robin Dunbar in the 1990s.

Intimate Bonds

Closest family and friends

Close Friends

People you turn to for support

Meaningful Connections

Regular social contact

150

Stable Relationships

People you know personally

Network Visualization

Connections

All

Layer

The Science Behind Dunbar's Number

Robin Dunbar discovered this limit by studying the relationship between brain size and social group size in primates. The neocortex ratio (the part of the brain responsible for conscious thought and language) strongly correlates with the maximum group size that a species can maintain.

For humans, this translates to approximately 150 stable relationships. This number appears consistently across human societies throughout history - from Neolithic villages to military units to modern social networks.

The layered structure (5, 15, 50, 150) reflects the cognitive effort required to maintain relationships at different levels of intimacy. Each layer requires increasingly more mental resources to track and maintain.

In the digital age, while we might have thousands of social media connections, research suggests we still can only meaningfully engage with around 150 people, supporting Dunbar's original hypothesis.