They can tell you the intimate details of an ant's sex life - and they will. They're waiting for you in the kitchen at your next party, ready to hijack perfectly interesting conversations with their unremarkable, unedited views on life. Beware the bore. Beware being the bore...
somewhere, back before the mists of antiquity (but a bit after the primeval sludge), our australopithecine ancestors developed boredom. This was in the days when survival meant something more urgent than owning a four-wheel drive and being connected to the Internet. Above all it required alertness - the capacity to recognise new stimuli and to respond to them. This meant the urge to explore - or as the social psychologist Norman F Dixon put it in his book, Our Own Worst Enemy - to reduce ignorance.

The trouble was, as Dixon pointed out, this urge to explore contradicted the need to conserve energy. The two had to be balanced somehow. After a bit of sitting around conserving, something had to impel our predecessors to get up off their hairy backsides, out of their caves and reduce their ignorance. The answer was boredom.

That is why the consequences of boredom can be so profound. The reason why some people believe that they experience boredom as an almost physical discomfort, is because they really do feel pain. Ex-smokers will recognise the feeling as being like sitting in a long meeting, unable either to smoke or to leave. You begin to go up the wall. The act of thinking, it seems, increases cranial blood flow and cerebration. Boredom, by contrast, can cause atrophy. It kills yer brain.

And it gets worse. Dixon quotes an experiment described in the gloriously boringly titled Effects of decreased variation in the sensory environment, by W E Bexton et al. Back in the 1950s three Canadian head doctors paid a series of male students the then vast sum of $20 a throw, to lie in bed in a soundproofed room, wearing translucent goggles, and with cardboard tubes on their arms. In other words they were being paid to be Canadian students - except that they couldn't watch television, listen to loud, discordant music, or play with themselves.

They went mad. After a couple of hours they began to experience bizarre and disturbing hallucinations (their mothers had refused to do their laundry, duvets had disappeared from the face of the earth, their tutors were replaced by Jeremy Paxman etc). Most gave up well before the allotted time, losing their money in the process.

All of which makes Bores criminals. Bores are men and women who, by their behaviour and speech, cause discomfort, cerebral damage and (with prolonged exposure) lunacy in others. Marriage to a bore is a life sentence in a padded cell. As Parliament considers the new no-fault divorce legislation, it ought to ask itself whether a partner's proven high bore quotient oughtn't to be grounds for immediate separation. Industrial tribunals ought to be asking bosses, "Did you tell the joke about the knight on the shaggy dog six times in one month, as alleged, Mr Slapp?" and making awards accordingly.

Let us make some distinctions here. As Richard Hoggart complains these days, there is too much relativism about. I can already hear the cries of "but we're all of us boring sometimes". Indeed you are. We are. Especially with spouses or children, when we're not trying so hard to impress or seduce. We reach into the old ragbag of cliches our mothers told us, and drive our families barmy with inhaled tedium. "A stitch in time ... if a things worth doing ..." etc. In my case it is the appalling need to remind others of my extraordinary wisdom and prescience. The Told You So bore is ever present inside me, just awaiting an opportunity to jump out and sink its fangs into someone's neck. I am also capable of spending (to my shame) five hours at a time being the playmaker at Huddersfield Town in Player Manager, a computer football simulation game.

But we are not talking here about such part-time or fair-weather bores. For there are human beings who are perpetually boring. People upon whose approach hope fades and vivacity withers. People in whom variety is not only finite, but finis - whom custom stales within milliseconds. And there are several distinct types, whose boringness stems from different causes:

Type 1. The Moaner. The person whose psychological, physical, spiritual or emotional woes are so overwhelming that there is nothing, but nothing, else that they can talk about. They show their scars, describe their hernias, recommend their therapists, and above all, share their pain with you.

The most obvious example here is the Princess of Wales. When Diana came out into the street on that famous occasion after a gruelling session of therapy and cried, her therapist Susie Orbach was quite probably doing the same thing in her back garden. One day her family will find her suspended from the ornamental peach, a short letter beneath the dangling but finally peaceful corpse.

Note: real moaners are not to be confused with the temporary variety, who are usually smokers enduring cold turkey, and dieters. Their madness will pass.

Type 2. Tramliners. These are the voluble holders of totally predictable (and usually somewhat fatuous) opinions. They are essentially cliches on legs. To them all politicians are the same - out for themselves. They believe that if foreigners are going to live here, then they must make an effort to integrate. Homosexuals are fine as long as they don't thrust it down your throat. No sooner have they begun the sentence then you know how it will end. No. You know how the sentence will end before it's even begun, just by the dead look in their eyes, or what is on the telly or has been in the papers.

Type 3. Anoraks. Many of us are part-time enthusiasts. I myself, holder of three anti-boredom diplomas, can nevertheless conduct a conversation on the theme: was 1986-87 a better season for Tottenham Hotspur than 1970-71?

True anoraks, however, insist on engaging those who really are not interested in their hobbies in any way. The Daily Record Boring Hubby of the Year Award for 1995 was won by a man who insisted on talking to anyone who would listen to him about ants. How they lived, where they lived, what they ate, how they organised and so on. His wife put it succinctly. "I do not care about ants". Somehow, despite everything, he carries on.

Anoraks can be devious too. They hijack conversations, imposing their own critical paths on argument. Take the chap who grows his own vegetables. No matter where you started you'd always end up in the same place.

Path 1. Politics - Tony Blair - Labour Party - working class - allotments - vegetable-growing - prize marrows - best fertilisers. Path 2. Culture. Pride and Prejudice - television drama - locations - country houses - kitchen gardens -vegetable growing - prize marrows - best fertilisers.

Type 4. Explainers. Those who insist on laying the whole thing out for you, no matter what stage you are at in understanding the issue. They always give the full exegesis, not wanting you to miss a thing. Complain about Noel Edmonds and you risk a description of the basis upon which the BBC was founded.

Type 5. Aggrandisers. It doesn't matter what the topic, however technical or abstruse, the aggrandiser has done it. Has been there. Has got the t-shirt. Has designed the t-shirt. Or his sister did. You can't mention anal sex without him telling you that a good friend has a little house there, just by the beach. Often visits. Knows all about it. You were saying?

That's the who. What about the why? Why do bores bore? After all, most of us are absolutely terrified of being thought in any way boring. Given a choice between public incontinence and condemnation for being tedious, most of us would surrender control of our bowels. To this end we engage in a multitude of stratagems designed to help us avoid being boring. Many women (who are far more socially aware than men as a rule) will adopt the "beautiful, but pensive" pose at parties, simply so that they cannot possibly bore anybody. Let the men do that.

The rest of us examine those with whom we are speaking for signs of their true response. We pause for encouragement or affirmation, we note nods of the head, shrugs, grimaces, smiles and signs of dissent. If the other person has glazed eyes, does not move, and their breathing ceases, we know not to continue. But not bores. Why? What has gone wrong?

The first possible explanation is that these people are themselves incapable of being bored. They do not recognise the condition. The gene creating curiosity and wonder is somehow missing.

But if you cast your eye around you will see that two classes of mankind are more prone to boring behaviour than others: powerful people and good people.

Powerful people do not have to care whether or not they're boring. In fact the capacity to cause pain through boredom is a sign of their puissance. Easily bored themselves, they take a perverse pleasure in watching underlings pretend that their eight-hour speeches (Castro), interminable proverbs (Mao) and repetitive strictures (Thatcher) are fascinating.

Then there are the good. Whether they mutter platitudes in a mixture of Albanian and bad Italian (like Mother Teresa), or condole from the pulpit with the relatives of the recently departed, we do not send them the right signals. We hate to upset the good. So what if Uncle Morry insists upon telling us for 40 minutes about caravan stabilisers - it's a small price to pay. And he might leave us something. If we can only stay awake.