The Rule of 150: Why Growing Organisations Lose Their Story
The Rule of 150 is not really about headcount. It is about the moment when shared meaning stops travelling naturally — when the story that once held everything together begins to thin. A practical exploration of what organisations lose as they grow, and how to protect it.
The Rule of 150: Why Growing Organisations Lose Their Story
The Rule of 150 — often associated with Dunbar’s Number — suggests there may be a cognitive limit to the number of stable social relationships humans can maintain before cohesion begins to fray.
The science is contested. The number itself is neither precise nor universal.
But as a lens, it remains useful.
Because what it really describes is not a threshold.
It is a moment.
A moment when familiarity fades.
A moment when shared understanding weakens.
A moment when the story that once held everything together begins to thin.
Editor's note — where this sits
This essay uses Dunbar's Number as a lens for understanding how organisations lose their story as they grow — and why narrative, not structure, is what holds shared meaning together. It sits in the Map layer of the Idea to Value system — the layer concerned with direction, the painted picture, and the story that orients a whole organisation. It also connects to the Physics layer, where energy fragments when alignment weakens, and the Wiring layer, where the erosion of shared meaning is ultimately a communication failure.
The Idea to Value system — five layers
As organisations grow, communication does not simply increase; it multiplies.
More people mean more connections,
and more connections mean more opportunities for drift, duplication, and misunderstanding.
Without deliberate care, people stop working through the system and start working around it.
New joiners arrive without a lived sense of history.
Remote teams develop strong local bonds but lose connection to the whole.
Even headquarters can fragment when culture is unevenly articulated.
People naturally adopt the behaviours of those closest to them.
When those behaviours are grounded in purpose, continuity is preserved.
When they are not, micro-cultures form, each carrying its own rules, priorities, and internal narratives.
This is not a failure of people.
It is the predictable outcome of growth without clarity.
Every organisation has a centre of gravity and a story.
It is carried by the people who shaped it
— founders, early contributors, long-standing participants who remember why the organisation exists, how it learned to survive, and what it stands for.
At any point in time, the business is an outward expression of those people.
As the organisation grows, those people cannot be everywhere.
Unless the story is carried forward intentionally
— through leadership, onboarding, behaviour, and everyday decisions
— connection to the core weakens.
When people lose the story, they lose context: why decisions are made, why work flows as it does, what “good” actually means here.
This is where the Rule of 150 quietly appears
— not at a specific headcount, but at the point where shared meaning no longer travels naturally.
Sub-cultures are inevitable.
Isolation is not.
As teams scale, groups form identities.
Problems arise when those identities lose sight of the whole, when trust between teams erodes, and when local optimisation overtakes collective purpose.
The organisation begins to feel like several smaller companies sharing a logo.
Work fragments,
coordination costs rise,
and value-creating activity is drowned out by internal friction.
From an Idea → Value perspective, this is where cost expands
— not because people stop working,
but because energy and attention is fragmented and no longer aligned toward common outcomes.
The symptoms appear first in human signals.
People arrive and remain unknown.
People leave quietly.
Teams criticise one another without understanding constraints.
Work is duplicated.
Failure demand grows.
Individuals quietly compensate for systemic gaps until they burn out.
Leadership often responds with process, governance, and reporting.
But process cannot restore connection.
Compliance cannot replace care.
The system becomes anxious rather than agile.
Customer value rarely sits within a single function.
It moves across boundaries before it becomes real.
When those boundaries harden, value slows.
When priorities compete, work stalls.
When investment spreads thin, nothing finishes.
Clarity precedes flow.
Until leaders decide where energy will move
— and where it will not
— the system cannot move easily from idea to value.
The answer to the Rule of 150 is not structure.
It is management as connection.
Managers sit at the boundary between strategy and reality,
between the organisation’s past and its future,
between people and the systems they inhabit.
They carry the story, or they do not.
Policies cannot reconnect people to purpose.
Story must be lived, emotional, and consistent.
When new teams form, the presence of people who carry the organisation’s story matters more than any organisational chart.
In the end, countering the Rule of 150 requires something simple and demanding: acting like founders.
Founders care about the whole.
They protect energy and attention.
They connect decisions to value.
They carry a painted picture of the future and behave as though it matters.
When organisations do this well, growth does not dilute culture.
It extends it.
When the story holds, people do not merely work together.
They belong to something worth building, and they become authors of its next chapter.
Idea → Value System
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The system this article draws on directly — a practical way of seeing how energy, attention, and investment either flow toward value or fragment into internal friction. When the story weakens, the Physics layer shows where the cost accumulates.
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A half-day experiential seminar that makes the symptoms described in this essay visible — fragmentation, competing priorities, internal friction — and helps leadership teams see where the story is thinning and where to intervene.
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