Why we all love a fight

Why am I obsessed with violence? Journalists covering protests are often accused (by non-violent protesters, funnily enough) of only caring when it erupts into a fight. The critics have a point. Violence always gets more column inches: just think of the coverage that the recent Sea Shepherd ramming got, compared to Greenpeace's ongoing anti-whaling actions. Or the pages devoted to the English Defence League (rucking all over the country) as opposed to Voices in the Wilderness's long-running anti-war, non-violence, direct-action campaign. Or the amount of chatter about Climate Camp when it was on the verge of invading Heathrow Airport and surrounded by hundreds of police, compared to its peaceful encampment at Blackheath last summer.

But why do we react like this to violence? What differentiates violence as a campaign tactic from, say, a protest camp or a blockade or a banner drop? I've been pondering this for a long time, and I've come up with three reasons, one rational, one chemical and one honest.

First of all, violence is a violation of the social contract. Human society is set up, as Hobbes and Locke explained, with a kind of giant, invisible agreement: we will abdicate authority and power to the rulers of our society if, in return, they guarantee to protect us from violence against ourselves and our property. You may not remember signing this, but that is the deal, and if anyone (apart from the police or the army - the only two groups, according to the contract, which are authorised to be violent) hits someone, steals their property or blows things up, they are breaking the contract.

Blockades and that sort of thing, depending on their seriousness, are more like attempts at renegotiating the deal. Sometimes they get good results. But one of the jobs of the journalist is to look out for the contract, and particularly for any serious infractions by either the people or the state. So, reason one is: "We're just doing our job, sir."

Second, violence causes a chemical reaction in the onlooker. Mirror neurons in the human mind fire off identical hormones when we perform an action or see it performed by someone else. Adrenaline, the hormone that is released when we are in stressful situations, is a stimulant and pretty addictive stuff. Most activists, even if they won't admit it, get a bit hooked on the excitement of an action, and almost all journalists mainline the stuff like it's Buckfast. (There's actually an Adrenaline Addicts Anonymous. I'm thinking of nominating every single journalist and activist I've ever met for it.)

Third, the honest explanation: it's interesting. Anyone who has ever seen a fight break out and has an honest streak in their body will admit that, at some level, they just wanted to stand and gawp. There is a moment in a bar, or at a gig, or at a protest, when anything could happen. When violence begins to break its way up through the concrete, suddenly everything you know about people is useless and that isfascinating.Frightening, upsetting and terrifying in the way it can spiral out of control, in the way that violence breeds more violence, more anger and pain. But fascinating, too.

Bibi van der Zee's column runs fortnightly

Next week: Mark Lynas