Definition: Humans have a cognitive limit of approximately 150 people with which they can maintain personal relationships.
Insight: The number (150) has remained relatively constant throughout history, geography, or activity.
Insight: Dunbar argues that this is directly related the the physical size of the neocortex, the part of the human brain responsible for conscious thought, logic, and language.
Insight: Organisations should not consist of groups of people in the smallest networks of more than 150 - many organisations use this number as the guide to the maximum number for the efficiency of teams, groups, and departments.
Reference: Origin: The work of evolutionary biologist Robin Dunbar on the human brain and social groups.
Example: The size and configuration of armies across the world and throughout history: consist largely of platoons (10-15 soldiers), companies (3-4 platoons), battalions (3-4 companies).
Definition: A theoretical cognitive limit on the number of stable social relationships humans can maintain at any given time.
Insight: Beyond our limited circle (around 150 people) we start to treat people less like individuals and more like objects.
Insight: For decisions that impact people outside our limited circle, it can be helpful to 'personalise' decisions by imagining how they might impact people within our circle.
Principle: Imagine how those within your circle might respond if they were directly impacted by the decisions you make.
Definition: The number of individuals with whom any person can maintain stable relationships.
Insight: As leaders of larger organisations, it can be important to broadcast communication to all employees through channels like email, so that they feel more of a personal connection.
Insight: It is impossible to build strong relationships with many people - we simply do not have the time.
Principle: Maintain regular emails to all employees.
Definition: The cognitive limit to the number of people with whom we can have a stable social relationship (approx 150).
Insight: Our social brains are wired to focus on a relatively small number of people, within a close distance to us.
Definition: 150 - the theoretical limit for the number of people a human can maintain in their social circle.
Key Insights & Principles
Relationships & Leadership
There is a cognitive limit to our social capacity.
For maximum efficiency, organisations should not consist of groups of people that are larger that approximately 150.
Beyond our cognitive capacity, we start to treat people more like objects than people.
When making decisions that impact people outside our social circles, we should imagine how the decisions would impact people closest to us or how they might respond.
Utilise communication tools like email to maintain regular contact with all employees.
