For centuries western culture has been permeated by the idea that humans are selfish creatures. That cynical image of humanity has been proclaimed in films and novels, history books and scientific research. But in the last 20 years, something extraordinary has happened. Scientists from all over the world have switched to a more hopeful view of mankind. This development is still so young that researchers in different fields often don’t even know about each other.

When I started writing a book about this more hopeful view, I knew there was one story I would have to address. It takes place on a deserted island somewhere in the Pacific. A plane has just gone down. The only survivors are some British schoolboys, who can’t believe their good fortune. Nothing but beach, shells and water for miles. And better yet: no grownups.

On the very first day, the boys institute a democracy of sorts. One boy, Ralph, is elected to be the group’s leader. Athletic, charismatic and handsome, his game plan is simple: 1) Have fun. 2) Survive. 3) Make smoke signals for passing ships. Number one is a success. The others? Not so much. The boys are more interested in feasting and frolicking than in tending the fire. Before long, they have begun painting their faces. Casting off their clothes. And they develop overpowering urges – to pinch, to kick, to bite.

By the time a British naval officer comes ashore, the island is a smouldering wasteland. Three of the children are dead. “I should have thought,” the officer says, “that a pack of British boys would have been able to put up a better show than that.” At this, Ralph bursts into tears. “Ralph wept for the end of innocence,” we read, and for “the darkness of man’s heart”.

This story never happened. An English schoolmaster, William Golding, made up this story in 1951 – his novel Lord of the Flies would sell tens of millions of copies, be translated into more than 30 languages and hailed as one of the classics of the 20th century. In hindsight, the secret to the book’s success is clear. Golding had a masterful ability to portray the darkest depths of mankind. Of course, he had the zeitgeist of the 1960s on his side, when a new generation was questioning its parents about the atrocities of the second world war. Had Auschwitz been an anomaly, they wanted to know, or is there a Nazi hiding in each of us?

I first read Lord of the Flies as a teenager. I remember feeling disillusioned afterwards, but not for a second did I think to doubt Golding’s view of human nature. That didn’t happen until years later when I began delving into the author’s life. I learned what an unhappy individual he had been: an alcoholic, prone to depression. “I have always understood the Nazis,” Golding confessed, “because I am of that sort by nature.” And it was “partly out of that sad self-knowledge” that he wrote Lord of the Flies.

I began to wonder: had anyone ever studied what real children would do if they found themselves alone on a deserted island? I wrote an article on the subject, in which I compared Lord of the Flies to modern scientific insights and concluded that, in all probability, kids would act very differently. Readers responded sceptically. All my examples concerned kids at home, at school, or at summer camp. Thus began my quest for a real-life Lord of the Flies. After trawling the web for a while, I came across an obscure blog that told an arresting story: “One day, in 1977, six boys set out from Tonga on a fishing trip … Caught in a huge storm, the boys were shipwrecked on a deserted island. What do they do, this little tribe? They made a pact never to quarrel.”

The article did not provide any sources. But sometimes all it takes is a stroke of luck. Sifting through a newspaper archive one day, I typed a year incorrectly and there it was. The reference to 1977 turned out to have been a typo. In the 6 October 1966 edition of Australian newspaper The Age, a headline jumped out at me: “Sunday showing for Tongan castaways”. The story concerned six boys who had been found three weeks earlier on a rocky islet south of Tonga, an island group in the Pacific Ocean. The boys had been rescued by an Australian sea captain after being marooned on the island of ‘Ata for more than a year. According to the article, the captain had even got a television station to film a re-enactment of the boys’ adventure.

I was bursting with questions. Were the boys still alive? And could I find the television footage? Most importantly, though, I had a lead: the captain’s name was Peter Warner. When I searched for him, I had another stroke of luck. In a recent issue of a tiny local paper from Mackay, Australia, I came across the headline: “Mates share 50-year bond”. Printed alongside was a small photograph of two men, smiling, one with his arm slung around the other. The article began: “Deep in a banana plantation at Tullera, near Lismore, sit an unlikely pair of mates … The elder is 83 years old, the son of a wealthy industrialist. The younger, 67, was, literally, a child of nature.” Their names? Peter Warner and Mano Totau. And where had they met? On a deserted island.

My wife Maartje and I rented a car in Brisbane and some three hours later arrived at our destination, a spot in the middle of nowhere that stumped Google Maps. Yet there he was, sitting out in front of a low-slung house off the dirt road: the man who rescued six lost boys 50 years ago, Captain Peter Warner.

Peter was the youngest son of Arthur Warner, once one of the richest and most powerful men in Australia. Back in the 1930s, Arthur ruled over a vast empire called Electronic Industries, which dominated the country’s radio market at the time. Peter was groomed to follow in his father’s footsteps. Instead, at the age of 17, he ran away to sea in search of adventure and spent the next few years sailing from Hong Kong to Stockholm, Shanghai to St Petersburg. When he finally returned five years later, the prodigal son proudly presented his father with a Swedish captain’s certificate. Unimpressed, Warner Sr demanded his son learn a useful profession. “What’s easiest?” Peter asked. “Accountancy,” Arthur lied.

Peter went to work for his father’s company, yet the sea still beckoned, and whenever he could he went to Tasmania, where he kept his own fishing fleet. It was this that brought him to Tonga in the winter of 1966. On the way home he took a little detour and that’s when he saw it: a minuscule island in the azure sea, ‘Ata. The island had been inhabited once, until one dark day in 1863, when a slave ship appeared on the horizon and sailed off with the natives. Since then, ‘Ata had been deserted – cursed and forgotten.

But Peter noticed something odd. Peering through his binoculars, he saw burned patches on the green cliffs. “In the tropics it’s unusual for fires to start spontaneously,” he told us, a half century later. Then he saw a boy. Naked. Hair down to his shoulders. This wild creature leaped from the cliffside and plunged into the water. Suddenly more boys followed, screaming at the top of their lungs. It didn’t take long for the first boy to reach the boat. “My name is Stephen,” he cried in perfect English. “There are six of us and we reckon we’ve been here 15 months.”

The boys, once aboard, claimed they were students at a boarding school in Nuku‘alofa, the Tongan capital. Sick of school meals, they had decided to take a fishing boat out one day, only to get caught in a storm. Likely story, Peter thought. Using his two-way radio, he called in to Nuku‘alofa. “I’ve got six kids here,” he told the operator. “Stand by,” came the response. Twenty minutes ticked by. (As Peter tells this part of the story, he gets a little misty-eyed.) Finally, a very tearful operator came on the radio, and said: “You found them! These boys have been given up for dead. Funerals have been held. If it’s them, this is a miracle!”

In the months that followed I tried to reconstruct as precisely as possible what had happened on ‘Ata. Peter’s memory turned out to be excellent. Even at the age of 90, everything he recounted was consistent with my foremost other source, Mano, 15 years old at the time and now pushing 70, who lived just a few hours’ drive from him. The real Lord of the Flies, Mano told us, began in June 1965. The protagonists were six boys – Sione, Stephen, Kolo, David, Luke and Mano – all pupils at a strict Catholic boarding school in Nuku‘alofa. The oldest was 16, the youngest 13, and they had one main thing in common: they were bored witless. So they came up with a plan to escape: to Fiji, some 500 miles away, or even all the way to New Zealand.

There was only one obstacle. None of them owned a boat, so they decided to “borrow” one from Mr Taniela Uhila, a fisherman they all disliked. The boys took little time to prepare for the voyage. Two sacks of bananas, a few coconuts and a small gas burner were all the supplies they packed. It didn’t occur to any of them to bring a map, let alone a compass.

No one noticed the small craft leaving the harbour that evening. Skies were fair; only a mild breeze ruffled the calm sea. But that night the boys made a grave error. They fell asleep. A few hours later they awoke to water crashing down over their heads. It was dark. They hoisted the sail, which the wind promptly tore to shreds. Next to break was the rudder. “We drifted for eight days,” Mano told me. “Without food. Without water.” The boys tried catching fish. They managed to collect some rainwater in hollowed-out coconut shells and shared it equally between them, each taking a sip in the morning and another in the evening.

Then, on the eighth day, they spied a miracle on the horizon. A small island, to be precise. Not a tropical paradise with waving palm trees and sandy beaches, but a hulking mass of rock, jutting up more than a thousand feet out of the ocean. These days, ‘Ata is considered uninhabitable. But “by the time we arrived,” Captain Warner wrote in his memoirs, “the boys had set up a small commune with food garden, hollowed-out tree trunks to store rainwater, a gymnasium with curious weights, a badminton court, chicken pens and a permanent fire, all from handiwork, an old knife blade and much determination.” While the boys in Lord of the Flies come to blows over the fire, those in this real-life version tended their flame so it never went out, for more than a year.

The kids agreed to work in teams of two, drawing up a strict roster for garden, kitchen and guard duty. Sometimes they quarrelled, but whenever that happened they solved it by imposing a time-out. Their days began and ended with song and prayer. Kolo fashioned a makeshift guitar from a piece of driftwood, half a coconut shell and six steel wires salvaged from their wrecked boat – an instrument Peter has kept all these years – and played it to help lift their spirits. And their spirits needed lifting. All summer long it hardly rained, driving the boys frantic with thirst. They tried constructing a raft in order to leave the island, but it fell apart in the crashing surf.

Worst of all, Stephen slipped one day, fell off a cliff and broke his leg. The other boys picked their way down after him and then helped him back up to the top. They set his leg using sticks and leaves. “Don’t worry,” Sione joked. “We’ll do your work, while you lie there like King Taufa‘ahau Tupou himself!”

They survived initially on fish, coconuts, tame birds (they drank the blood as well as eating the meat); seabird eggs were sucked dry. Later, when they got to the top of the island, they found an ancient volcanic crater, where people had lived a century before. There the boys discovered wild taro, bananas and chickens (which had been reproducing for the 100 years since the last Tongans had left).

They were finally rescued on Sunday 11 September 1966. The local physician later expressed astonishment at their muscled physiques and Stephen’s perfectly healed leg. But this wasn’t the end of the boys’ little adventure, because, when they arrived back in Nuku‘alofa police boarded Peter’s boat, arrested the boys and threw them in jail. Mr Taniela Uhila, whose sailing boat the boys had “borrowed” 15 months earlier, was still furious, and he’d decided to press charges.

Fortunately for the boys, Peter came up with a plan. It occurred to him that the story of their shipwreck was perfect Hollywood material. And being his father’s corporate accountant, Peter managed the company’s film rights and knew people in TV. So from Tonga, he called up the manager of Channel 7 in Sydney. “You can have the Australian rights,” he told them. “Give me the world rights.” Next, Peter paid Mr Uhila £150 for his old boat, and got the boys released on condition that they would cooperate with the movie. A few days later, a team from Channel 7 arrived.