In the 1960s, the psychologist Stanley Milgram conducted his iconic “shock experiments”. An “experimenter” instructed each participant to give an unseen person in an adjacent room electric shocks of increasing severity via a control panel. The participants were told that the experiment was testing the effect of punishment on learning. They heard screams of pain in apparent response to their actions, although in reality no one was being hurt.

Milgram was fascinated by how far the participants would follow the inhumane instructions of the experimenter. His results suggested that many normal people would be prepared to do terrible things if someone in authority told them to.

Read more about “the banality of evil”: “Just obeying orders? Rethinking obedience and atrocity“.

Milgram’s theatrical experiments were and are influential, but they had a cost: the participants were induced to experience extreme emotional stress. For that reason, they are considered to be among the most unethical ever carried out. Academic standards have moved on, and professional psychologists could not now replicate Milgram’s experiments. Some other studies from the 20th century were intriguing but would also be ethically impossible today, too. Here are four more.

The three Christs of Ypsilanti
In 1959 psychologist Milton Rokeach brought three psychiatric patients who each thought they were Jesus Christ to live together for two years at Ypsilanti State Hospital in Michigan. His aim was to see if this unusual set-up would alter their delusions. .

Project MKUltra
In this from the 1950s and 60s, the mental states of participants – often unwitting ones – were manipulated using mind-altering drugs, hypnosis and sleep deprivation. The exact details are hard to establish, as many of the MKUltra documents were destroyed, but some tests proved lethal. Most notoriously, CIA scientist Frank Olson died in mysterious circumstances after consuming a drink laced with LSD.

Little Albert
In this famous 1920 experiment on emotional conditioning, a 9-month-old boy, “Albert B”, was first exposed to various stimuli, including a rabbit and a rat, of which he was not afraid. When the appearance of the animal was accompanied by a loud bang, Albert quickly began to .

Not only was the experiment inherently cruel, but Albert was not helped to overcome his conditioned fears.

Robbers Cave
To examine how competition between groups affects social relations, psychologist Muzafer Sherif conducted a series of studies between 1949 and 1954 at summer camps for boys in Robbers Cave State Park, Oklahoma. He assigned boys who were friends with each other to different groups and then had them compete for scarce resources. A series of aggressive encounters between the groups ensued – though the animosity was later overcome by team-building exercises.

The main ethical problem here was that the boys were unaware they were taking part in an experiment in which their worlds were being deliberately manipulated.

One of the common methods that politicians use to strangle debate is to pass description off as explanation. Prime Minister David Cameron’s statements in the days following the English riots are a classic example of this. On 11 August, the day after order returned to the streets, he asserted to the House of Commons that the disturbances were “criminality pure and simple”. Later, at a youth centre in Witney, he stressed the events were not about race, social welfare cuts or poverty. “No, this was about behaviour.”

Of course, he was right in characterising looting, arson and violence as criminal acts. Equally, the riots were self-evidently about behaviour. But what caused this behaviour? To insist that it is enough to apply the criminal label is to prevent us even asking these essential questions.

Another way in which politicians have restricted explanation is by intimating that any reaction other than condemnation is tantamount to condoning violence. The UK’s education secretary Michael Gove reacted furiously to the suggestion by Harriet Harman, deputy leader of the Labour party, that government policies limiting youth opportunities might have had some relevance, castigating her for “making excuses for what has gone on here”. In this context, whole academic disciplines become suspect: in political vocabulary, “sociologist” and “jihadi” have acquired a kind of moral equivalence.

“In political vocabulary, ‘sociologist’ and ‘jihadi’ have acquired a kind of moral equivalence”

It is worth noting that much contemporary social science – including my own discipline of social psychology – arose out of an attempt to understand the Holocaust. Many of the leading post-war social psychologists were Jewish scholars. Their aim was not to condone but to gain practical insights that would give substance to the slogan “never again”.

Those politicians and pundits who have tried to outlaw societal explanations of the English riots have advanced alternative theories, largely blaming the violence on the pathology of the rioters. Cameron’s declaration that they are inherently criminal and lack moral standards is one variant of this. Another is the common suggestion that the rioters lost their moral standards in the crowd; that they were mindless, swept up by the contagion of the moment or perhaps preyed upon by unscrupulous agitators.

These theories translate into convenient solutions. In the short term, don’t try to reason with rioters but use a big stick to repress them; in the longer term, look at the sickness within their communities that has turned them into amoral beasts. That only leaves the question of which communities are dysfunctional and in what ways. Thus Cameron locked horns with former prime minister Tony Blair over whether we should be talking about a broken society or a narrow but recalcitrant underclass.

The first problem with all this is that we do not yet know exactly who participated in the riots, what sections of society they came from, why they participated and what they did. How can we explain an event when we do not know the true nature of it? The second problem is that explaining the disorder in terms of the pathologies of those who took part – they must be either mad or bad – flies in the face of all we know about crowds and riots.

Perhaps the greatest investigation into the nature of riots was the Kerner Commission, established by US President Lyndon Johnson to find out the causes of the civil unrest that erupted in Detroit and other US cities between 1965 and 1967. The commission sent teams of investigators into the affected communities to study those who had taken part. What they found challenged many preconceptions about what had happened.

For example, the investigators acknowledged that many people took advantage of the disturbances to pillage and settle scores, and that this increased with time. But they also discerned clear patterns in the events. They showed that the average rioter was not marginal or part of an underclass but was generally better educated and socially integrated and had less of a criminal record than the norm in their communities.

Furthermore, the rioters did not act mindlessly and randomly, rather their targets reflected communal grievances. This reflects the finding from crowd psychology that crowd members do not lose identity or become “deindividuated”. They act meaningfully in terms of the collective identities, values and understandings shared by their communities. Finally, the commission found no indication that the riots were directed or planned by organised groups, despite Johnson’s conviction to the contrary.

The UK government needs to instigate a Kerner Commission of its own – an independent, in-depth investigation of this summer’s riots that will tell us about the people and communities involved. So far it has resisted calls for anything beyond deputy prime minister Nick Clegg’s “victims’ panel”, which will take evidence from residents in affected areas. When it comes to root causes, all we have been offered is a choice between a lack of explanation, uninformed explanation and mis-explanation. This approach might serve the short-term interests of those in authority, but it is unlikely to generate solutions that work in the longer term. For that, we need solid evidence and sound science.