A disturbing French TV documentary has tried to demonstrate how well-meaning people can be manipulated into becoming torturers or even executioners.
The hugely controversial Game of Death was broadcast in prime-time on a major terrestrial channel, France 2, on Wednesday.
It showed 80 people taking part in what they thought was a game show pilot.
As it was only a trial, they were told they wouldn't win anything, but they were given a nominal 40 euro fee.
Before the show, they signed contracts agreeing to inflict electric shocks on other contestants.
One by one, they were put in a studio resembling the sets of popular game shows.
They were then asked to zap a man they believed was another contestant whenever he failed to answer a question correctly - with increasingly powerful shocks of up to 460 volts.
Egged on by a glamorous presenter, cries of "punishment" from a studio audience and dramatic music, the overwhelming majority of the participants obeyed orders to continue delivering the shocks - despite the man's screams of agony and pleas for them to stop.
This programme denounces manipulation by authority but at the same time it manipulates people
Marie-France Hirigoyen Psychiatrist
Eventually he fell silent, presumably because he had died or lost consciousness.
The contestants didn't know that the man, strapped in a chair inside a cubicle so they couldn't see him, was really an actor. There were no shocks and it was all an experiment to see how far they would go.
Only 16 of the 80 participants stopped before the ultimate, potentially lethal shock.
"No one expected this result," intoned a commentary. "Eighty per cent of the candidates went to the very end."
The show was billed as a warning against blindly obeying authority - and a critique of reality TV shows in which participants are humiliated or hurt.
Some of the participants smiled or laughed nervously as they delivered the shocks, although most were obviously stressed and troubled by the action.
Many said they wanted to stop but were convinced by the presenter to continue.
The show was inspired by an experiment at Yale University in the 1960s by social psychologist Stanley Milgram.
He used similar methods to investigate how people could come to take part in mass murder.
Jean-Leon Beauvois, a psychologist who took part in the documentary, says he and other members of the team spent months analysing the results.
"When they signed the contract, participants were placed in the position of executioners," he said.
"These were people like others, not exceptional, but 80% of them let themselves be drawn into becoming torturers."
For Mr Beauvois, it showed the "terrifying power of TV".
The documentary asserted that most people are conditioned from childhood to obey.
It made the argument that only those with experience of rebelling can muster the strength to disobey orders from an authority figure - in this case the presenter, backed by pressure from the audience.
One contestant said afterwards that her grandparents had been Jewish Holocaust victims and she regretted that she'd obeyed orders to keep inflicting shocks.
Another, originally from Romania, said her experience of living under Ceausescu's regime had given her the strength to say no.
Some participants felt emboldened by the show, the producer says
In a studio discussion after the documentary was aired, psychiatrist Claude Halmos said the experiment showed that it was important to explain rules to children and not just impose them.
"We have to teach children to obey," she said, "but we must also teach them to disobey."
The producer, Christophe Nick, said the show had changed the lives of many participants. Some, he said, had become bolder about standing up to their bosses.
But one woman who had obeyed orders was shown close to tears afterwards. "How will I tell my husband and my children what I've done?" she asked.
Psychiatrist Marie-France Hirigoyen, who had no part in the documentary, said she accepted that it could help viewers understand the importance of standing up to an abusive authority, but she was concerned about its effect on participants.
"This programme denounces manipulation by authority but at the same time it manipulates people," she told the BBC.
"I wouldn't have accepted this show because I think it inflicts unnecessary trauma on people, but on the other hand, to get this message across, you probably need to be sensationalist."
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