The Week in Radio: When the voice of the people carries lots of weight

Heavy conversation: Radio 2's Jeremy Vine (BBC)

If the riots were about divisions in society coming to the fore, then radio phone-ins are similar, without the window-breaking and the plasma screens. Take the explosive mix of tensions, prejudice and bigotry that kicked off on Jeremy Vine's phone-in on fat people.

"Is it time to stigmatise being fat?" enquired Jeremy as though that proposal was perfectly mild, and not as inflammatory as lobbing a petrol bomb through the window of Comet. "I'm sorry if that sounds blunt, it's just how it is. Should people be weighed and measured at airports?"

There was the obligatory interlude with experts. Nina Myskow said stigmatising fat people made them gain weight and Rachel Agnew believed fat people "make excuses". But it's when he lifts the stone and invites the real people in that Vine's programme comes alive because real people don't mince their words.

Vine put size-18 Alison in Bedford up against Steve Roberts in Cambridge who believes there should be "fat seats" on trains and airplanes. "It's galling when people are travelling on low-cost airlines and you're in a queue with an enormously obese person who God forbid you're sitting next to," moaned Steve. "I cannot believe that I'm hearing this," gasped Alison. "You don't want to hear it because you're overweight and you're selfish," Steve responded. And so it went on.

At their worst, phone-ins are the junk food of radio, a forum for people with anger issues to trade insults. Commercial radio thrives on them and Radio 4 avoids them, and yet Jeremy Vine has evolved a successful middle way, allowing the visceral divisions in society to be starkly presented, encouraging confrontation without indulging bigots and leavening real people with a judicious amount of experts.

Another ingenious way for people to discriminate against each other, but one that has had a relatively low profile so far in Britain, is caste. In The British Caste Conundrum, the comedian Paul Sinha explored the belief of some British Asians that caste discrimination is on the rise. According to Caste Watch UK, caste is the "Asian disease" and is now causing a major problem in British society as people barricade themselves into their religious identities. This was a fascinating topic but I could have done a lot more basic information about the caste system and how it affects Hindus and Sikhs. Sinha did, though, highlight a tricky dilemma – should discrimination on grounds of caste be illegal, or would legislation only make things worse? As the Hindu Forum of Britain, which opposes the inclusion of caste in the Equality Act, pointed out, the white British have castes of their own. "People lower down are called chavs and there's no system for them to go to a tribunal."

China has traditionally avoided the divisions that religion causes – by banning it. Yet there are now signs that the Communist Party is using religion to fill the void created by Western-inspired materialism. This was the intriguing starting point of Tim Gardam's God in China, which sets out to explore the rapid growth of China's five official religions Taoism, Buddhism, Islam, Catholicism and Protestant Christianity. There have been plenty of programmes exploring China's material development, but this is the first I've heard examining the spiritual turmoil that goes with it. "We have had vigorous growth but no one's thinking could keep up and some young people have felt an emptiness," explained one Taoist. "Religion can bring comfort to their hearts."

Gardam's quest made intriguing listening and if he did occasionally have the air of a 19th-century explorer – "I've come from Oxford in England, a long way away," he announced to one living goddess – perhaps that's because so few have yet ventured into the complex terrain of China's spiritual malaise.