Manners, Lily - it's so not cool to lash out

She's not alone. Cheryl Cole has been appointed the empathetic new judge on The X Factor. Nobody seems to think she disqualified herself when she lashed out at a lavatory attendant who merely asked her to pay for some sweets she had taken. Both John Prescott and Prince Harry were cheered for throwing punches. Jonathan Creek and QI star Alan Davies even bit a homeless man's ear outside the Groucho Club but we still see him as a cuddly national treasure.

There have always been violent celebrities but this snickering applause is a return to an earlier, cruder age. Londoners used to cheer public executions and stroll past heads on spikes on London Bridge, but gradually praise for public violence faded. By the 1960s, if Lulu had beaten up a member of the public or Ronnie Corbett had set upon a tramp, their careers would have been over.

Still, we mustn't be naïve and nostalgic about that time. Wives and gay people were bashed with impunity. I don't agree with David Cameron that our society is " broken" now but was by implication "fixed" then. But in this one crucial area - abuse and public indifference - we are regressing.

You can see this all around us, usually in more subtle shades. It's considered normal now to go into a shop and buy something while talking on your mobile, without even acknowledging the minimumwage worker behind the till.

Are there political causes? The period when it was least acceptable to cheer on public aggression was the 1950s to 1970s, when the classes were moving closer together in income and life chances. But for three decades now we have been pulling apart again: London is more unequal today than at any time since 1937. All over the world, the most unequal cities have the most paranoid and envious cultures. You are more likely to lash out at people you think are nothing like you. Look at Johannesburg or Houston or São Paulo: as London mirrors

Their income distribution, we mirror their aggression. The solution is partly political and partly personal. It's hard to be kind when everyone around you is jostling and yelling and goading the Lily - but it is even more essential. When he was dying Aldous huxley wrote: "It is a bit embarrassing to have been concerned with the human problem all one's life and find at the end that one has no more to offer by way of advice than 'try to be a little kinder'." We can all start by acknowledging that a punch in the face is not a punchline.