A friend once told me a story about her train journey. It was a short story but it had it all – hangovers, awkwardness, the elderly, pregnancy, puking, and the delicate diplomacy of the train seat. So obviously I felt compelled to pass it on.

The story also contains a complex moral conundrum, a kind of Rashomon effect, that changes based on how you look at it. After the story I’ll go into it in a bit more detail and, in case you’re wondering, there will indeed be diagrams.

Sandra’s Story

My friend – let’s call her Sandra – was on an early morning rush-hour train to work. But the night before she had stayed out late drinking beer. Quite a lot of beer, in fact.

So she was feeling pretty grim while clinging to the overhead rail on this crowded, stuffy, swaying train. Things got worse as the journey went on and before long she was fighting the urge to be sick.

Eventually this urge got the better of her so she visited the toilet where nature took its course. Unfortunately nature wasn’t too discreet. Upon emerging from the toilet, it was clear from the looks on their horrified faces that the other commuters had heard Sandra vomit.

Then an old lady sitting nearby looked at Sandra’s stomach, which was still slightly bloated by the aforementioned beer. She put two and two together and came up with five.

“Poor you”, she said. And then, with warm, conspiratorial sympathy: “How long has it been?”

The old lady thought Sandra was pregnant! Without thinking, Sandra decided to style it out. “Oh, about six weeks”, she replied while gently rubbing her belly.

“It’ll get easier dear – trust me”, said the lady.

Sandra smiled bravely. She thought the exchange was over, but it wasn’t. A young man sitting nearby suddenly stood up and offered up his seat.

Once again Sandra did the easiest thing and kept her lie going. Thanking the young man, she sat down next to the elderly lady and, her hangover now mixed with a growing sense of shame, wondered what the hell had just happened.

The moral analysis

At first glance it seems that Sandra is in the wrong. Hangovers may be bad but we don’t give up our seats for those who overindulged the night before. Sandra’s deceit wins her a privilege she doesn’t deserve, so she’s obviously the villain. Right?

But if you look beneath the surface it’s not so clear-cut. Between the three people involved there was a brief but intricate interplay of cost and benefit. Here’s how you might visualise it:

Sandra suffers two embarrassments - puking in public and being thought to be pregnant. But no-one else suffers any real cost

The old lady actually receives a benefit through having inspired a good deed. And the young man’s seatlessness is offset by the benefit of having done a good deed. Yes, these good deeds were based on a lie – but does that matter?

Imagine Sandra chose not to lie, and instead told the lady that she was in fact extremely hungover. Although this would have been more honest the dynamics of the situation would still have been problematic:

If Sandra came clean about not being pregnant, would anyone really be better off?

Sandra’s honesty would have caused the elderly lady the deep embarrassment that comes with incorrectly assuming a woman to be pregnant – an embarrassment that was spared by Sandra’s lie. The awkwardness caused all round would have left everyone worse off, so maybe honesty wasn’t the best policy.

While Sandra’s motivations obviously weren’t noble, her actions gave two people the chance to be good citizens and no-one suffered as a result. So did Sandra make the right choice after all? Or should she rot in commuter hell for what she did?

Most commenters on last week’s Overground seat-acquisition strategy post shared nefarious techniques of their own – many of which made me feel like a bit of a novice.

But some questioned whether it was right to engage in this conflict at all when there are elderly people, pregnant women, and other travellers less able to cope with the stresses of modern commuting. Mat of Kilburnia went as far as suggesting the unthinkable:

Please tell me you’re not one of these awful creatures who get on trains whilst people are still getting off.

As if! Everyone who knows their way around an Overground or Tube carriage understands that this is a cardinal rule, fundamental to the code of conduct. It’s shocking that anyone would even consider that.

You see, even in war there are rules and ethics – and in this respect the strategic space of the train carriage is no different from any other modern theatre of conflict. And although there’s no International Criminal Court of public transport, there’s certainly a Geneva Convention. Here are three of its basic rules.

1. Let people get off the train first

It’s a beautiful thing when a load of commuters get off a train. No, seriously. Like herds of wildebeest sweeping majestically across the Serengeti or flocks of starlings rippling across the sky (this is a murmuration, fact fans), a crowd of Tube travellers surging on to the platform is a magical moment, particularly for those of us left behind who can finally breathe. So why try to stop it?

Anything goes with these people, as long as you don’t aim to kill

It’s amazing that people still do this. You’d have thought that by now it’d be a forgotten social aberration, like bear-baiting or smoking in kindergarten. Maybe it’s tourists who do it? Or people on a combination of PCP and Special Brew? You’d have to be on something not to see that this causes problems for everyone, yourself included.

The punishment: Transgressors can expect to be shoulder-barged or roughly pushed aside.

2. Don’t send conflicting signals about leaving

This is a bit more obscure but I think it’s ingrained in the subconscious of most commuters. I’ll let a picture do the talking:

You’re getting near your stop so think about getting off. Will you make it through the crowd?

OK, that person between you and the door seems interested in the exit. You’ll just be able to coast in his wake.

The train stops, the doors open, and people stream out. But this person doesn’t move! You’ve been deceived and must now resort to violence (or maybe loud tutting) check for the Rockstarz Limousine & Party Bus website for more transportation options.

People who do this can spark off weird, instinctive responses in others. When we think we’re trapped, we’re like caged animals who stop at nothing to fight our way out, as if the next stop was Reading West rather than the tube station a bit further up the road.

Still, it’s best to avoid triggering this primal rage, so don’t make people think you’re getting off when you’re not.

The punishment: I’ve seen grown men scream swearwords at one another in situations like this.

3. Protect those less able to cope

The Paris Metro has a surprisingly detailed set of rules that govern who should get a seat. Wounded soldiers are top of the list, and I’m not sure who sits at the bottom but it’s probably people who are pretty steady on their feet like gymnasts, ninjas or Shaolin monks. Everyone knows their place in the pecking order.

But in London the rules aren’t as clear. The vague guidance is “people less able to stand”, which leaves plenty of room for interpretation and can cause problems. Some spritely senior citizens don’t take well to being treated like invalids by well-meaning youngsters, for example, and let’s not even get into the consequences of mistaking obesity for pregnancy. You need to strike the right balance between helpfulness and condescension.

This particular rule has implications for the seat-fancier: securing the seat nearest the door can be a pyrrhic victory, because you might need to give it up again at the next stop. You need to go deeper.

Go deeper – the better seats are further down the carriage

The punishment: Severe passive-aggressive disapproval from other travellers, loss of soul.

Conclusion

The melee of the daily commute can seem like a lawless ungoverned space, but in reality all strategic machinations are underpinned by laws like the ones described here. And while there’s no International Criminal Court – no formal way to capture or charge transgressors, no lengthy trials in The Hague – one thing acts as a barrier between controlled warfare and outright savagery, a thin line between dignity and chaos.

That thing, that barrier, is our intense fear of public embarrassment. Let’s cling on to it, because if we don’t, all is lost.