In 1988 Phil. S. Ensor coined the term the functional silo system.  His contention was that narrow, specialised teams and jobs were easy to manage, but imposed damaging learning disabilities on the organisation.

Social chasms emerge resulting in people not seeing any problem in context. Indeed – cross organisational problem solving can break down.

Silos exist for many reasons: some of them very positive and even essential. However, I’ve been thinking about silos that shut themselves off from the world. Those that perceive outside interference and connectivity as a threat.

I spent a week in January in the Andaman Islands, in the northeastern Indian Ocean. Whilst geographically close to Myanmar and Thailand, politically they are part of India.

Whilst I was there I heard stories about an island that might be the most effective silo system on earth.

North Sentinel Island is off-limits to everyone. Step foot on the beach and you are very likely to be killed. If you survive, you’ll get 3-5 years in an Indian jail.

There is no electricity, no light to break the night sky, and certainly no digital footprint—the island is a literal dead zone for Wi-Fi and mobile signals. Without agriculture or even metal, their existence is stone-age; they rely on the forest for wild pigs, and the sea for molluscs and fish.

The Sentinelese left Africa roughly 60,000 years ago and for the vast majority of that time, they have existed in a state of total autonomy. They are the ultimate uncontacted tribe, protected by a strict five-mile exclusion zone enforced by the Indian government.

The government maintains an “eyes-on, hands-off” policy for the 50-150 people that live there. Indeed, no-one really knows what the exact population is, as an official census is impossible.

This has created a unique legal situation: The Sentinelese are effectively treated as an autonomous entity. If they kill a trespasser, the Indian government will not prosecute the tribespeople. The law recognises their right to defend their isolation and protects them from the introduction of outside diseases.

But how, and why, have the Sentinelese maintained such an effective silo, that has completely held off the progress of the rest of the world?

History suggests their aggression is a learned survival strategy rather than an inherent trait. In the mid-19th century, records from passing ships occasionally described the islanders as curious or simply indifferent.

The turning point occurred in 1880, when British officer Maurice Vidal Portman kidnapped two adults and four children for study in the nearby island of Port Blair. The adults died almost immediately from lack of immunity to common diseases. Whilst the surviving children were returned with substantial gifts , they carried pathogens that devastated the tribe. This contact was a trauma that fundamentally altered their worldview: outsiders equal death.

Every attempt to introduce the modern world to the Sentinalese has failed and only hardened their resolve. As recently as 2019, John Allen Chau, a 26-year-old American missionary, was killed by bows and arrows after illegally visiting the island to convert the protected tribe to Christianity.

The Anatomy of the Defensive Silo

Now, let’s be clear, I’m not suggesting that the silos that exist within our organisations have been born out of trauma, but their defensive mechanisms can be triggered by ‘unwanted outside interference’.

Boundary hardening is a defensive process where organisational silos become increasingly rigid and impermeable in response to external pressures or perceived threats.

Silos evolve into hardened bunkers when they encounter outside interference, which acts as a primary catalyst for defensive isolation. This hardening typically occurs through two main mechanisms:

Outside-in buffering: Teams harden their borders to protect members from disturbances like top-down commands or external changes that interfere with localised productivity.

Inside-out buffering: Teams defend their borders to prevent the leakage of core knowledge or proprietary information to external teams. Inside-out buffering is the ultimate power play: teams weaponise their expertise by making sure their ‘core knowledge’ never leaks across the border

How to Build a Bridge (Without Getting Shot)

‘Rogue silos’ can be frustrating to deal with and even harder to connect with. The first thing to understand is they didn’t start that way, just as the Sentinalese, their defence mechanisms have been built up over time, for a reason.

Outsiders can often unwittingly barge into these silos with a sort of saviour complex. We walk in with our latest innovation, our new strategy, our agile frameworks, ignoring the fact that the people inside the silo have spent a lot of time developing survival mechanisms that work for them. When we ignore their context, we shouldn’t be surprised when they reach for their bows and arrows.

Acknowledge the Perimeter: Don’t pretend the silo doesn’t exist. Acknowledge that they have built these walls for a reason. Respect their specialised language and KPIs before you try to change it.

The “Gifts” Approach: Early (and much safer) contact with the Sentinelese involved dropping off coconuts and iron tools—things they actually needed. Don’t bring disruption; bring solutions to their specific pain points.

Diplomacy over Conquest: You cannot force a silo to integrate. You have to prove that the outside world is a partner, not a threat.

Building a bridge to these rogue units requires more than a mandate; it requires the diplomacy of someone who respects their history and can show that connecting to the rest of the organisation means a gain in impact, not a loss of identity.

Silos aren’t built by lazy people; they are built by talented people who feel that the rest of the organisation is a pathogen.