In Scotland’s grittier pubs, a simple rule has long applied: no football colours and no talking about politics. With enough drink, talking about either can lead to violence — and pint glasses are expensive to replace. With an ordinary general election, the prohibition is easy to obey. The wrong buggers might well win, but they can easily be removed at the next election.

A referendum, however, is different. It’s not just temporary — it’s for life. And like life, it’s unavoidable. Socially, as well as politically, there is no hiding place. The Prime Minister is, it seems, experiencing the referendum effect for himself. He can quite happily chat to his opposite number in the Labour party (after all, if it weren’t for Jeremy Corbyn, the Tory civil war might prove ruinous) and he still takes a kindly interest in the remaining Liberal Democrats. But Tories who are fighting him over Brexit? They are beyond the pale. It’s reported that he struggles to make eye contact with them, so infuriated is he by their treachery.

Not that David Cameron will be the only person to discover this. As Scots can tell you, nothing plays havoc with your social life like a referendum. There’s nothing so galling as discovering someone you thought was One of Us is actually One of Them.

Some 97 per cent of eligible Scots registered to take part in the independence referendum, and nearly 85 per cent actually voted. It was all-consuming, all--encompassing, all-everything. In the aggregate this created something stirring: a nation solemnly weighing its own future and determining not just its own fate, but the future of the rest of the United Kingdom. The turnout showed how seriously Scots took their responsibilities as citizens. It was a democratic carnival of a kind none of us had previously experienced. There was something valuable about it and, at times, even something noble.

But that was the aggregate experience. Individual stories were often rather different. For every person excited, enthused and energised by the referendum there was another who found the process depressing, exhausting and even, in some instances, terrifying.

A referendum debate is like an irregular verb: I am rational, you are misguided, he is deluded. In the first instance there were many — particularly, it must be acknowledged, those in the upper-income brackets — who disliked even having to think about the question. The answer, after all, was head-snappingly obvious: Scotland should vote ‘no’ to independence. What a nonsense it all was; why were we even having this debate? Unionist Scotland didn’t want the fight and resented being dragged into it. In similar fashion, denizens of London’s affluent salons cannot fathom why the EU referendum is taking place. The Kippers are revolting but, gosh, this prosecco is charming.

Social invitations, disagreeable in quieter times, become intolerable with the certain knowledge that discussing politics is inescapable. ‘Must we go?’ I’d ask my wife, noting we had ample supplies of food at home. Alas, too often, we did have to, ensuring another evening of half-baked constitutional analysis disguised as a passionate ‘engagement’ with, first of all, the issues and, more dreadfully still, the meaning of identity and nationhood. You’d look around the table and see friends who up until then you’d respected talk the most stunning rot. And they’d think the same of you.

In one sense this was appropriate. The stakes were high: the outcome would affect everyone, from the richest voter to the poorest. But it caused trouble too. You were often surprised. Folk you assumed would vote one way would express the opposite preference. For unionists, in particular, such discoveries could be disconcerting. It began to seem as if the game might indeed be up. The steady accumulation of anecdote began to feel something like data.

Of course, you would agree to disagree and you would maintain a veneer of politeness, but beneath the surface you began to wonder if these people had succumbed to some kind of intellectual virus or if they had always been like this and you just hadn’t noticed.

If truth is the first casualty of referendums, friendship is the second. One pal admitted ‘defriending’ most of her yes-voting Facebook chums and only reluctantly granted her yes-supporting brother a reprieve. All across Scotland there were families divided by the national question. Unlike previous conflicts, there was no way of taking out insurance, no way to hedge bets — no modern version of the old Highland ploy of sending one son to fight for the Jacobites while enlisting another in the government’s army.

There were many mixed marriages in which one party voted ‘yes’ and the other ‘no’. Some were even happy marriages, in which both parties cast their ballots out of conviction — not just to spite and thwart their spouses. Anglo-Scottish marriages felt the strain most severely. ‘I’m leaving Scotland if it’s “yes”,’ one English-woman of my acquaintance told her independence--supporting husband. ‘Fine,’ he replied. ‘I’m not.’ From that point on, they agreed a qualified peace. But it’s hard to have to treat even the breakfast table as a demilitarised zone.

When it comes to the EU referendum, you can expect more of the same, particularly if your spouse hails from another country in the union. Marriages may well be tested when one person’s vote to leave will — in some mysterious, inchoate, sense — be perceived as a repudiation of the other’s identity. ‘So you’re just not into Europe, are you? Well, what about me?’ And then there will be a silence and a tacit agreement to speak no more of these matters… It’s politics, of course, but not as we know it.

Speaking of referendums, you are either ‘yes’ or ‘no’, ‘in’ or ‘out’, and there’s no way of bridging the divide. There is no room for compromise and it is winner-takes-all — with not even a consolation prize for the vanquished. Which is why, in the end, the best way to survive a referendum is to say nothing at all.

It's hard to have to treat even the breakfast table as a demilitarised zone

Alex Massie is the Scotland editor of The Spectator.