It was a hard night on Monday for many Australians as we watched the terrible pictures of child abuse from the Northern Territory. The next morning, I asked Jared Sharpe, one of the distraught lawyers from the Four Corners program, how this could be hidden for five minutes, let alone for so many years. He said it was from a “culture of cover-up”.

Jared was talking about the attitudes of a specific part of the Northern Territory, but I want to suggest to you that it is much wider than that. We should not be surprised that the sadistic abuse of these inmates had been hidden from us for so long, because it has been part of our country’s historical DNA since European settlement. Again and again, we have simply rounded up a group of difficult people and got them out of our sight.

It started with the British, of course. Their overcrowded prisons led to the hulks of the Thames, and it was inevitable that the next step was to keep those prisoners at sea and get those ships out of sight. Robert Hughes called it “the most extraordinary social experiment then imagined — the creation of a prison camp in the South Pacific for an entire criminal class”.

Historian Tony Moore, author of “Death or liberty”, told me that the British, wary of unrest in their little island, were “exporting revolution”. Rather than deal with their own problems in their own land, they simply flung them to the other side of the world.

Successive Australian governors behaved in exactly the same way. If convicts refused to behave in the correct manner, they were put out of sight. In this way, unspeakable punishments could be visited upon them, and Sydney Town could pretend it was a little civilised. Many convicts were sent all the way to Port Arthur, a name that soon became shorthand for psychological torture. Before Port Arthur was opened, the ruling Tasmanians could also pretend they were civilised, since the worst abuse took place out of sight on the other side of the Tasmanian wilderness, in Macquarie Harbour.

The further away the convicts, the worse the behaviour of their cruel commandants. As Robert Macklin writes in his recent book on Hamilton Hume:

“… the ne plus ultra of penal sadism was reserved for Norfolk Island, which on Lord Bathurst’s orders was to provide ‘a secondary punishment which will not admit of mitigation. I could wish it to be understood that the felon who is sent there is forever excluded from all hope of return.’”

There is an echo here in our recent border security advertisements, which say “If you come here by boat without a visa, you won’t be settled in Australia”. Forever excluded, in other words. Whatever you think of the refugee policies enacted by both Labor and Liberal governments, you cannot fail to recognise that the use of Nauru, Manus Island and Christmas Island is the latest chapter in our long history of putting a difficult problem out of our sight.

In a supreme irony, the colony of the “criminal classes” that England tried to bury on a desert island has turned out to be one of the most harmonious, peaceful and law-abiding societies on Earth. But in Don Dale Detention Centre, close to a place called Hidden Valley, there are still the echoes of the lash and the manacles.

Any parent, no, any grown human, knows that 13-year-old offenders need help, not torture. They need psychological care by professionals, not humiliation by thugs. But once these children become repeat offenders, once they are sent to “secondary punishment”, once they are hidden away, they become non-persons, just as they did two centuries ago. They are forever excluded. We can go on living our civilised lives and forget them, as we once forgot the doomed wretches sent to Norfolk Island.

* Nick Rheinberger (@nickrheinberger) is the mornings presenter with 97.3 ABC Illawarra.