How many of us think of ourselves as honest? Many more than have never lied, cheated or broken the law. Most people have done a bit of that, now and again – but probably consider the circumstances to be trivial, extenuating or exceptional. We wouldn't usually do it, we tell ourselves rightly or wrongly – we're basically honest.

Illustration by David Foldvari.

There are definitely people who basically aren't. Criminals, for example. Leaving aside the morally ambiguous – the grey economy, the cash economy, the City – there's still plenty of full-on, striped-jumper-and-swag-bag crime. Though the outfits may have changed – they certainly have for pirates. There are also confidence tricksters, online fraudsters and people who sell drugs or snaffle mobile phones to pay the rent. Or pay for drugs. (Why not just steal drugs? I could be a master criminal.) Do people with such unequivocally dishonest sources of income think of themselves as basically honest too? Do they think, "Most people lie all the time – I only do it at work!"?

And what of the conversational liars? We all know one or two. People who seem to have fascinating lives, who come across as fun and interesting, but then it dawns on you that they're making everything up. They tell enthralling anecdotes beginning, "You'll never believe what happened to me the other day!" knowing you will even though it didn't. Then the penny drops and your own nodding and smiling becomes a lie as well, covering private speculation as to whether it's sociopathy or low self-esteem that makes them so weird. How do people like that internally rate their own honesty? Do they lie, even to themselves, about their lying?

Or do the thieves, drug dealers and people who claim to have met Ringo Starr in Asda tell themselves that honesty is overrated? "Look at Simon Cowell – he sometimes tells the truth about people's singing and you can see their hearts breaking, live, in front of him. The truth is pain, failure, injustice and the inevitability of death. To keep bringing that up is sadistic." Maybe they think truth and goodness are mutually exclusive and propose a utopia of the lie, centred on comforting conversational fictions and readily available opiates. Or perhaps they just hate themselves.

I'd be interested to know where, in this Bermuda triangle of self-delusion, self-loathing and hatred of truth, German doctors Entscho Wladow and Michael Elinescu lost their souls. Historically speaking, the phrase "German doctors" has implied far worse than anything Wladow and Elinescu have done – they only cheated at bridge. Still, it was the world championship finals and, as a result, Germany won, beating the USA. This outcome seems likely to be reversed now that a World Bridge Federation report has exposed the doctors' cough-based cheating system. They may appeal but, as things stand, they remain unappealing and have been banned from the game for 10 years.

I find their behaviour odd. The key aim in bridge is to convey to your partner which cards you've got, and so how many tricks you might win if a certain suit is trumps, exclusively through the medium of the game's arcane bidding system. You're not allowed simply to say what's in your hand. You're not allowed to hum "Diamonds are Forever", mime a heartbeat or waggle your eyebrows in the direction of a shovel or double-decker sandwich, and you're certainly not allowed to do significant coughs. That's the point of the game, like not using your hands in football. Without it, it's pointless. If you're not into that, bridge is not the pastime for you. There is no earthly reason to play it unless you derive some satisfaction from communicating a hand of cards without coughing.

So what motivated the Germans' actions? Prize money? It can't be life-changing, surely. To prove to the world that Germany is better than America? No one is ever going to believe that. Those huge endorsement deals from manufacturers of small pads of paper that await all international bridge champions? It must be that – because, to my mind, whatever you stand to gain in terms of pride and glory from triumphing in such an event would be utterly negated if you knew you hadn't honestly won. That buzz from proving you're the best at bridge – the vindication high – simply wouldn't come, because you'd know you weren't. It's like the difference between having sex with Marilyn Monroe, and merely telling everyone you've had sex with Marilyn Monroe and somehow they all believe you. If you consider the latter experience to be effectively as good as the former then you've got a screw loose.

Much more comprehensible, in my view, are the actions of Michaela Hutchings from Lichfield, who last week was convicted of dishonesty for going on a spending spree when the council accidentally dumped £52k into her bank account. She immediately blew nine grand on shoes, handbags and sunglasses, and posed for several photos while enjoying what the newspapers implied was council champagne. Obviously that's not what you're supposed to do – I don't approve of her actions, but I do understand them (generally speaking – I don't quite get how you can spend £9k on accessories unless you're the stock buyer for a department store). Money, unlike victory in contract bridge, doesn't entirely lose its charm when you haven't earned it.

Personally, though, I don't think I'd have done what she did either. I'm not staking an ethical claim – I just don't like decisions and, it seems to me that, if you're always open to lying, cheating or dishonestly obtaining, it generates thousands of extra decision-making scenarios. You've been given £5 too much change – should you mention it? Someone's left their phone behind – should you tell them or keep it? This restaurant seems inattentively staffed – should you pay or just leave?

I'd rather take the honest course by default than undergo dozens of moral dilemmas and risk assessments. I suppose I could also avoid those decisions if my default was dishonesty – but I'd find that stressful. The rare occasions when I've broken rules or laws led to traumatic breaches in my peace of mind. It's a frailty of gumption that, luckily for me, shares the symptoms of a moral compass.

Honesty is very convenient – and that's probably why most of us are mostly honest most of the time. Society functions more smoothly if the statistical risk of being misinformed, robbed, ripped off or murdered in any given situation remains low. The fact that most people realise this is a felicitous confluence of common sense and laziness – as much a victory of apathy over enterprise as it is of righteousness over sin.