The first clue that things are done very differently on Bastoy prison island, which lies a couple of miles off the coast in the Oslo fjord, 46 miles south-east of Norway's capital, comes shortly after I board the prison ferry. I'm taken aback slightly when the ferry operative who welcomed me aboard just minutes earlier, and with whom I'm exchanging small talk about the weather, suddenly reveals he is a serving prisoner – doing 14 years for drug smuggling. He notes my surprise, smiles, and takes off a thick glove before offering me his hand. "I'm Petter," he says.

Before he transferred to Bastoy, Petter was in a high-security prison for nearly eight years. "Here, they give us trust and responsibility," he says. "They treat us like grownups." I haven't come here particularly to draw comparisons, but it's impossible not to consider how politicians and the popular media would react to a similar scenario in Britain.

There are big differences between the two countries, of course. Norway has a population of slightly less than five million, a 12th of the UK's. It has fewer than 4,000 prisoners; there are around 84,000 in the UK. But what really sets us apart is the Norwegian attitude towards prisoners. Four years ago I was invited into Skien maximum security prison, 20 miles north of Oslo. I had heard stories about Norway's liberal attitude. In fact, Skien is a concrete fortress as daunting as any prison I have ever experienced and houses some of the most serious law-breakers in the country. Recently it was the temporary residence of Anders Breivik, the man who massacred 77 people in July 2011.

Despite the seriousness of their crimes, however, I found that the loss of liberty was all the punishment they suffered. Cells had televisions, computers, integral showers and sanitation. Some prisoners were segregated for various reasons, but as the majority served their time – anything up to the 21-year maximum sentence (Norway has no death penalty or life sentence) – they were offered education, training and skill-building programmes. Instead of wings and landings they lived in small "pod" communities within the prison, limiting the spread of the corrosive criminal prison subculture that dominates traditionally designed prisons. The teacher explained that all prisons in Norway worked on the same principle, which he believed was the reason the country had, at less than 30%, the lowest reoffending figures in Europe and less than half the rate in the UK.