Unlikely as it may seem, Prince Philip, Duke of Edinburgh and consort to the Queen, is worshipped as a cult god on the Pacific island kingdom of Vanuatu.

According to ancient legend, villagers of the Yaohnanen tribe have long believed that the pale-skinned son of a mountain spirit would one day sail across the sea in search of a powerful woman to marry. When, in 1974 the Duke arrived on the island with Queen Elizabeth he was immediately declared to be that god and so the Prince Philip Movement was born. It is active to this day.

This is a cargo cult - a religious practice following interaction with technically advanced non-native cultures. Typically, cult leaders believe that material goods (cargo) brought by foreigners are created by spiritual means. Imitating the behaviour of these wealth holders will, sooner or later, convince the islanders' spiritual agents to award this cargo to the islanders.

World War II was the period of greatest cargo cult activity. First, the Japanese and then the Allied forces airdropped huge quantities of military equipment, weapons, tinned foods and clothing onto these Pacific islands. Then, when the war ended, the airbases were abandoned, the foreign soldiers disappeared and no further cargo arrived.

However, the islanders believed that ritual and magic could get the ships and planes to land again. Carving wooden headphones, they sat in fake control towers, and stood on disused runways waving imaginary landing signals. They made radios from coconuts and built airplanes from straw. Marching up and down using sticks for rifles, they painted Western military insignia onto their bodies. And they waited...and waited, but of course no cargo ever came.

Over the last 65 years most cargo cults have died out, although one, the John Frum movement, is still active in Vanuatu. In the 1940s, when 300,000 US troops arrived, the locals were impressed by the generosity of their wealthy visitors. The result was the creation of a mythic figure, John Frum: a combination of Uncle Sam, Santa Claus and John the Baptist. He is expected to return one day, and 15 February is still rigorously celebrated as "John Frum Day".

Cargo cults might seem to be the mark of less-developed nations resisting modernity and holding on to ancient superstitions and beliefs. However, if we look a little closer we can see similar practices in the so-called developed world.

There are examples all around us. Football fans, in their team shirts, are as tribal as any Papua New Guinea village elder. Week after week they go to their stadiums, performing ritual ceremonies, chanting magic slogans and exorcising demons. Once in a lifetime, their cargo ship might come to port (their team wins the cup) but mostly it never arrives.

In democracies people cast their votes in highly stylized ceremonies. Political parties have colours, slogans (Change you can believe in!), and we vote in the same place, in the same way, year after year. The change is rarely, if ever, delivered, but we never tire of repeating the ritual.

At a higher level, the term "cargo cult" includes any poor analysis of cause and effect. In this way, Maoism was "cargo cult Marxism" while cargo cult science produces flawed results based on uncertain assumptions, with the usual goal being only that of winning more research funding.

In sport, politics, economics or science, we follow cargo cult thinking just as much as any Pacific islander. It may look different, and is expressed differently, but we are just as obsessed with rituals, and we wait just as patiently for longed-for results, which usually never arrive.

So we really shouldn't be surprised to see Prince Philip installed as a lesser pagan god on some sandy South sea island. Some of our cargo cults are just as strange...

Arthur Miller's "The Crucible" is one of the great plays of the twentieth century. A reaction to the McCarthy anti-communist campaign of the 1950s, it powerfully represents America's deepest Cold War anxieties and the fear of an invisible enemy - the famous "Reds under the bed".

In "The Crucible" we are back in 1692 in Salem, Massachusetts. Here a closed, puritanical community becomes obsessed with "witches in our midst". It is a story of betrayals, denunciations, jealousies and accusations. Collective paranoia has taken hold and victims must be found: only violence will satisfy the cold, cruel anger of the mob. The play ends darkly - the community has become hysterical, blood must be shed to calm the psychic frenzy, and the innocent must hang. And hang they do.

These days we don't exactly believe in witches, but the term "witch-hunt" is still in common use in English. Usually it refers to public accusation in the media in response to some deep anxiety that seems to build up in society - maybe as a result of religious, political or security fears.

In the Chinese Cultural Revolution of the 1960s, the slightest accusation of counter-revolutionary activities could result in a teacher ending up on a pig farm, shovelling manure for many a long year. Teenage students joining the Red Guards suddenly had a way to get back at teachers they didn't like. Or maybe they simply found themselves in the possession of a new kind of power that met some sadistic impulse. They could be cruel, without having to be accountable.

So what is it that leads a group of people to destroy an individual publicly? From where does humankind get this impulse? Reasons might include a desire for justice or revenge, the need to maintain group harmony or even the opportunity to express natural innate violence. Psychological explanations include in-group persecutions of the outsider, or Freudian ideas of unconscious projection of negative emotions onto a convenient target.

Witch-hunts are all around us. As I write, here in the UK a scandal is being revealed in the media. Politicians have been claiming excessive expenses, and the newspapers have found out.  Every day a new target is selected, and their expenses, either shockingly high or embarrassingly trivial, are revealed. Careers are, perhaps rightly, terminated. But the interesting thing is not the scandal itself but the way public anger is expressed. TV audiences boo and hiss, people jump up in political meetings, faces twisted in rage, to denounce "thieving toads". Anger is everywhere.

It is difficult to assess how real this anger is. The emotions are surely genuine, but they are expressed in a GROUP context, and how much does the individual truly own the anger of the group?

Group anger is a very unpredictable thing, and that is why we need the rebels, the individualists and the free thinkers to tell the group when it has gone too far. Of course, this could be a very dangerous position to be in, since the individual might quickly become a target him- or herself.

Challenging the group to support the victim of a witch-hunt requires great reserves of physical and moral courage. However, going against the herd has a vital role in a civilised society. And it is a role that is just as important today as it always was.