Road rage, trolley rage, airport check-in rage ... it seems we're all on the brink of flipping our lids. But while we must stay cool on the roads, psychologists recognise the cathartic effects of a good tantrum. In the first of a weekly series on emotions, David Cohen examines a vice that can become a virtue
My grandfather, a rabbi, was famous for his rages. He was once meant to be officiating at a funeral, when another rabbi arrived, and a disgraceful scene ensued as the two of them argued over whose funeral it was. It ended with my grandfather pulling the other rabbi by the beard and slinging him into the grave while the mourners looked on horrified. I thought, "So what? My grandfather has character."

A few months later, he blew his top again, this time at my wedding. Once more there was some affront to his authority, in this instance over the timing of the grace after meals. His face turning from white to red to purple, he started yelling over the microphone at the musicians, caterers and guests to "sit down and shut up". My mother tried to intervene, asking her father please to calm down, but it only made him more furious.

While this was happening, I downed an entire communal goblet of wine out of turn in sheer nervousness. Later I consoled myself: "I'm not like him." But was I?

These days, rage - be it rabbi rage, road rage, trolley rage, office rage or baggage-check-in rage - has become fashionable as the noun of choice to describe any situation fraught with bad or cathartic behaviour. Whether the cause of this rage epidemic is more people, more cars, more guns, more stress, or hotter weather, we seem to be noticing with some concern just how much rage surrounds us.

Yet, although we have become experts at nailing down other people's rage, we remain pusillanimously unhip to our own. Some 8 per cent of motorists claim to have been victims of road rage, for example, yet only 5 per cent admit to being perpetrators. A friend of mine berates road ragers as "stupid, sad, pathetic individuals", but becomes incandescent every time another motorist makes a move that is not to his liking.

Watching other people spontaneously combust can be terrifying if we are in the firing line, or amusing (how we laughed to see John Cleese as Basil Fawlty, kicking his Mini, or bashing Manuel with a frying pan!), but it is always larger than life and totally memorable. Our own rages, however ... that is another story.

In the garden of emotions, rage lurks in the dark shed full of cobwebs, stuck out of sight, seldom entered, where we chuck all the bits we prefer not to deal with. According to the Dictionary of Word Origins, the word "rage" is derived from the Latin word "rabies", meaning "madness, frenzy, fury", and comes to the English language via the Old French word rage, which has the dual meaning of "rabies" and "anger". The Shorter Oxford Dictionary retains these roots, defining rage variously as "madness" "violent anger", "vehement passion".

There is something primal about the experience of rage. Unlike anger, which comes from the heart and points the finger cleanly and directly, rage emanates from somewhere deeper and murkier, pushing through a trapdoor from inside the gut and rising up with frightening speed and ferocity, and with sometimes horrific consequences.

We are in danger, however, of trivialising rage by using it as a portmanteau for a whole jumble of unacceptable emotions. Every time someone makes a V-sign from behind the steering wheel we dub it road rage, but cutting someone up on the highway is more often plain rudeness than rage. Historically, there was something more epic about rage than the squalid grinding of bumpers or clash of supermarket trolleys. Rage is a mask which literally alters the colour and shape of the face and imbues the wearer with almost superhuman strength.

In previous eras, the power of rage often found a positive context. The rage of the warrior, for example - in Irish legend they were called "berserkers" - was venerated as the crucial attribute on which rested the survival of the tribe. And was rage not closely connected to the "passion" that spurs us to live life to the full? As Dylan Thomas enjoined us: "Do not go gentle into that good night/... Rage, rage, against the dying of the light." Then there was the "poet's rage", which conferred an artistic dimension. Rage is "noble" to Tennyson, "virtuous" to Pope.

But it is Shakespeare in Henry V who, in his sublime and prescient way, makes the distinction between rage as virtue and rage as vice:

In peace there's nothing that so becomes a man

As modest stillness and humility

But when the blast of war blows in our ears

Then imitate the action of the tiger

Stiffen the sinews, summon up the blood

Disguise fair nature with hard-favour'd rage

Then lend the eye a terrible aspect.

What Shakespeare foresaw and what we now subscribe to, was that rage is taboo in times of peace because it breaks the contract we tacitly make with civilised society, which is to act with self-control at all times. Self-control is regarded as a social good. But it is a fine line that we tread, because over-control - repression - is midwife to the most dangerous rage. It is repressed rage that results in the most extreme incidents - murder on the motorway, rape and horrific events such as those at Hungerford and Dunblane.

Richard Beckett, a forensic pathologist based in Oxford, whose work with people who commit "offences against the person" makes him an expert on aggression, says that there are basically two types of personality prone to inappropriate outbursts of rage. "The first type are, on the face of it, relatively calm and may function well on a week-to-week basis, but they absorb insult and frustration without outlet until a point where they explode. The actual trigger may be relatively minor, and often their rage is displaced - that is, they may end up attacking a person who is not actually the cause of their rage. These people are over-controlled and might do very extreme things. Thomas Hamilton, the Dunblane killer, probably fitted into this category. The other at-risk personality type is the under-controlled person who quickly and easily flies into a rage. Between the two is where we all want to be - the normal, functioning personality."

So what are we supposed to do with our rage? As one psychotherapist, John Rowan, says, context is all. "To express rage is healthy and normal, but it has to be expressed in a way that is not oppressive to others. All emotions need to be expressed. Rage wants to destroy something or somebody, but it doesn't have to end in violence. You can leave the scene, you can express anger. Only by owning up to our rage can we hope to achieve this, because otherwise it takes us over and we end up acting out our rage to the outside world in a manner that is shameful and destructive."

In my case, my unawareness of my rage nearly cost me my relationship. It was on a romantic weekend away in the days before I had children, before I was a writer. We'd had a wonderful time, but as we were preparing to fly back to our respective jobs, my partner commented that she thought my suits were "a bit square", and that perhaps I ought to buy some new ones.

I was wearing what I considered to be my zootest suit, and something inside me just flipped. I don't know where it came from, and it took me completely by surprise, but I screamed that she was "never, never to insults my suits". Then I ran to the window of our room - which was on the 13th floor - and threatened to throw the suits out of the window. I carried on in this pathetic fashion for about 15 minutes.

Afterwards, when I had finally finished catharting, my partner coolly told me that, in the light of this experience, she was re-evaluating if she wanted to continue our relationship. I was full of remorse, pleading that it was a one-off, that I had never done it before and never would again.

But she was right. Tantrum-throwing - particularly when I am preparing to leave for or return from a holiday - was much more a part of me than I had been willing to believe. Kleinian psychotherapists - who like to reduce everything to the "separation anxiety" that is hard-wired into us as a result of the rage we felt as babies when weaned off the breast - would have had a field day. But the fact remains that, unlike my grandfather, whose parents and 10 siblings were killed in the Warsaw Ghetto or the Nazi concentration camps, I had no long-burning excuse for my rage. Sure, criticism of the way someone dresses can cut to the core of their identity. But it was also funny. And perhaps she had a point?

"Most rage," says Beckett, "has a history, triggered by some feeling of insult, maltreatment, injustice or threat. Sometimes that hurt is real and needs to be appropriately expressed.

"There are three levels of rage, of which only two are acceptable: the first is the screaming and stamping of feet and use of abusive language, which is not directed at any individual; the second is all the above expressed towards inanimate objects, often manifesting as door-slamming, cushion- punching or object-throwing: and, finally, the most serious of all, which is directed at people.

"In dealing with this third manifestation of rage, some analysts covet the notion that we all have an enduring inner rage that can be tracked back to certain early-life experiences. I don't think we help people by reconstructing notions of primitive rage. A lot of angry people misinterpret events. It is more helpful to try to change their attitudes and to help them to reinterpret those triggers. And to teach them that one always has a choice."

Men are more likely than women to express their rage violently. The explanation goes that men are socialised into being "in control" and hence are more likely than women to be over-controlled, and that men are less articulate emotionally and hence less likely to express themselves verbally.

A counsellor from the Everyman Centre, London, who helps violent men to overcome their rages, says quite alarmingly that "it is common for men who are violent not to be able to remember their rage".

We should not be surprised. The language we use to describe our rage - such phrases as "overwhelmed", "beside oneself", "out of control" - are all attempts to disown the experience. "I was not myself" is the most common rationalisation. No wonder there is a powerful amnesiac quality to rage. But the fact that our rage happens when our defences are down means, quite simply, that it is deeply revealing of who we really are.