Jemima Lewis: Men are so much nastier than women

I'm sorry to bang on about Celebrity Big Brother, but as a means of anthropological observation it really can't be beaten. I always assumed, for instance, that women were the crueller sex. At primary school - while dangling glumly from a coat peg in the girls' locker room, or nibbling a sandwich in the loo rather than run the social gauntlet of the dining room - I often reflected on how much I would rather be bullied by boys.

From what I could see, boys just beat each other up and moved on, whereas girls specialised in psychological torture - exquisite, merciless and far more disfiguring.

It has, therefore, been a revelation to watch George Galloway, Michael Barrymore and Pete Burns at play. The big boys of the CBB house have distinguished themselves with the most hair-raising display of bullying ever seen on British television. Their victims have all been vulnerable women: first, the young glamour model Jodie Marsh, who left the house a weeping, trembling wreck; then the American actress Traci Bingham, a stranger in a hostile land, who was accused of being a gold-digging airhead with no talent beyond the size of her breasts; and now Rula Lenska, who made the mistake of admitting that she felt depressed about getting older and losing her sex appeal.

"Oh dear, what can the matter be, clapped-out actress stuck in the lavatory," sang the über-bitch Burns when Lenska's back was turned, while his pack sniggered and licked their wolfish chops.

You might argue that these particular men, with their monkey-skin coats, personality disorders and fondness for genocidal tyrants, are not representative of their sex - but you would be mistaken. A recent flurry of research suggests that men in general are far, far nastier than we ever imagined.

It is generally assumed, for instance, that gossiping is a female vice. But a new survey shows that men are the more unscrupulous scandalmongers. Twenty-four per cent of men, compared to 9 per cent of women, admit to having spread malicious rumours around the office to advance their own careers. Thirty-three per cent said they would happily repeat damaging gossip even if they knew it to be untrue. (Only 5 per cent of women said the same.)

Likewise, it turns out that a woman scorned is actually a pussycat: it's men who thirst for vengeance. Researchers at the University of London discovered this by asking volunteers of both sexes to play an investment game. They could choose to give their money to either of two bankers, one of whom had been briefed to shortchange them, and the other to give them a fair deal.

After the game, the investors were put into a brain scanner and shown images of the two bankers being given electric shocks. When they saw the good banker being tortured, the part of the brain associated with empathy lit up in both sexes. But when the dodgy banker was punished, the men's empathy zone went blank. Instead, the part of the brain associated with feelings of satisfaction started glowing.

The women, by contrast, could find no pleasure in the bad banker's pain. Their empathy zones remained illuminated, albeit somewhat muted, during his ordeal. Throughout the experiment, said psychologist Tania Singer, the men "expressed more desire for revenge" and derived greater enjoyment from "what they perceived as deserved physical punishment".

Dr Singer tried - as befits a woman - to cast a forgiving light on the men's behaviour. The male psyche, she explained, had developed a keener sense of schadenfreude because men were traditionally in charge of law and order. It wouldn't do for them to feel compassion when it was their job to marshal the mob against freeloaders and miscreants.

Evolution is God's gift to the male sex: a catch-all excuse for every kind of masculine vice, from infidelity to the fisticuffs. But perhaps Dr Singer has a point. Perhaps this - and not mere misogyny - is why women who gossip, bully or exact revenge are so much more vilified than men: because they seem to be neglecting their half of the evolutionary pact. If men provide the stick to beat society into shape, we must provide the carrot of kindness.

Curiously, in an age that worships emotional sensitivity above all else, the virtue of empathy seems to be in decline. As the furore over paedophiles shows, the public mood is one of vengeance and vigilantism; though when it comes to people being mugged or murdered in front of us, we are increasingly slow to step in.

Social breakdown has pushed all into smaller and more selfish worlds. The little acts of kindness that used to oil the wheels of neighbourliness are rarer now, because women have disappeared into the office.

"Kindness," said Goethe, "is the golden chain by which society is bound together." If women can no longer provide enough to go round, men will have to pick up the slack. The apes of the Big Brother house should be a wake-up call to mankind: it's time for an emotional evolution.