One of the most famous psychology experiments, conducted by Stanley Milgram, revealed that ordinary members of the public obeyed authority figures, to the extent of even possibly killing, or seriously hurting, innocent people.
Obedience to bad authority is probably responsible for much cruelty and injustice in the world. Both of us saw this when we worked in the NHS, and have written about the rarity of whistle-blowing.
Three key figures in modern history, Mohandas Gandhi, Martin Luther King and Nelson Mandela, liberated peoples and countries by promoting disobedience to authority.
Why and how some disobey, and continue to do so, regardless of the overwhelming pressure and persecution, could help us understand why some revolutions succeed, while others (the Arab spring?) fail. It could also improve the lives of millions around the world, as more disobedience to bad authority is essential.
The World Leaders gathering in South Africa to celebrate the life of Nelson Mandela are precisely the one group who have least interest in Nelson Mandela's true legacy - disobey the rules when they are wrong. His real message is in danger of being air-brushed out of history.
Mandela's rebellious and insubordinate spirit could conveniently be forgotten by those who want to promote obedience. His remarkable life provokes the question of why some are not deterred from positive, pro-social, disobedient conduct by the prospect of punishment, whereas most are.
This is addressed in a study entitled 'A Comparative Study of the Autobiographies of M. K. Gandhi, Nelson Mandela, and Martin Luther King, Jr.', which recently examined the life histories of these three remarkably disobedient men, understanding where their ability to flout and challenge authority came from.
Davide Morselli, from the University of Lausanne, Switzerland and Stefano Passini, from the University of Bologna, Italy, contend that common themes emerge in early childhood and adolescent experience, which are key to how positive defiance originates. Computerised analysis of these heroes' autobiographies and biographies included strategies such as searches for key phrases such as ''I will never forget'' or ''That had a particular effect on my development''.
Morselli and Passini point out in their study, published in the academic journal 'Peace and Conflict', that all three rebels came from middle or upper-middle social classes. They had high social status within their own groups, so experienced vivdly the shock of discrimination by the ruling races and classes. They quote Mandela; ''No matter how high a black man advanced, he was still considered inferior to the lowest white man''.
This juxtaposition of pride and expectations of leadership and status, given their backgrounds and ability, coming up against the reality of under-class humiliations, may have been powerful psychologically in the moulding of all these men.
Morselli and Passini also point out how remarkable it is that all three men comment on the importance of their relationships with their own fathers (their first contact with authority) and their own fathers' relationship with the status quo. They quote Mandela as writing, 'My father had a stern manner and did not spare the rod when disciplining his children. He could be exceedingly stubborn, another trait that may unfortunately have been passed down from father to son... my father possessed a proud rebelliousness, a stubborn sense of fairness that I recognize in myself'.
Also key, according to Morselli and Passini, is how withstanding prison becomes central to resisting persecution and detention, without forsaking original goals and disobedience. Each of the three was imprisoned more than once. They coped and, it seemed, did so in part by not experiencing jail as an entirely negative experience.
Gandhi, Mandela, and King all re-interpreted their sentences as bearing witness to their dedication to the cause. The three rebels did not report the jail experience as a punishment, nor as an unwanted incident in their life trajectories.
All three were also sociable and social people, not remote leaders. Mandela wrote: 'We stayed in the Fort for two weeks, and despite the hardships, our sprits remained extremely high... Our Communal cell became a kind of convention for far-flung freedom fighters. Many of us had been living under severe restrictions, making it illegal for us to meet and talk... We revelled in the opportunity to exchange ideas and experiences for two weeks while we awaited trial.'
In other words prison was reframed as in fact, in some circumstances, an advantage to being on the outside.
Group cohesion also appeared to have been vital in maintaining unbowed resistance - none of these men achieved their defiance in any sense completely alone. Again Morselli and Passini quote Mandela; 'Mashall Square was squalid, dark, and dingy, but we were all together and so impassioned and spirited that I barely noticed my surroundings... I took pains to smile at the gallery when I walked into the courtroom, and seeing our supporters was the best medicine I could have had'.
All these rebels felt responsible for other groups in the same situation, then for the whole nation, creating a universal feeling of social responsibility. In the conclusion to his autobiography, according to Morselli and Passini, Mandela clearly illustrates this: 'The oppressor must be liberated just as surely as the oppressed. A man who takes away another man's freedom is a prisoner of hatred, he is locked behind the bars of prejudice and narrow-mindedness... The oppressed and the oppressor alike are robbed of their humanity.'
This week the tributes paid to Nelson Mandela have emphasised what a remarkable man he was, but there is a hidden danger in focusing on what he did as unique. Particularly if the world needs more and larger numbers of ordinary people to take up the cudgels of resistance from bad authority and resist, to break rules and be civilly disobedient, we need to understand how Mandela did it, and learn how to resist as he did.
According to Morselli and Passini all the processes which King, Gandhi and Mandela exemplify; questioning authority's legitimacy, disobeying its demands, withstanding its persecution, are not just personal characteristics of a few special people. These capabilities might be available to the rest of us.
Just as Stanley Milgram showed that under particular circumstances you can get people to obey authority even to extremes - so we need to better understand what it takes to generate more disobedience, even spectacular defiance, as exemplified by Mandela.
We can all learn to become a bit more like Nelson Mandela. And that should be his true legacy.