In the early 1970s I was a bemused ex-comprehensive schoolboy trying to make sense of Oxford University. One night as I walked home up Oxford High Street a group of Hooray Henrys were staggering down the other side. They were dressed in dinner suits (tuxedos), weaving around and shouting, and clearly wanted trouble. As a North East London lad who’d witnessed ‘bovver’ from skinheads, I kept my head down and avoided eye contact.

“Lefties!” they bawled. “We hate fucking lefties! Come on, lefties! We know you’re there! Show yourselves and get a thrashing!”

Sporting as I then did longish hair and a parka covered with vaguely hippie protest badges, I quickened my pace. I tried to blend with the front of All Souls College. It didn’t work.

“You sir!  You long-haired degenerate! You look like a fucking leftie! Come here and be thrashed!”

I had no intention of doing that, so I ducked into Catte Street and started legging it. Luckily they were either too drunk or too bored to chase me, and I lived to tell the tale.

Now I can’t say for sure whether they were members of the Bullingdon Club, the notorious posh dining, drinking and appalling-behaviour gang which once included David Cameron, George Osborne, Boris Johnson, Jo Johnson and David Dimbleby, not to mention the Duke of Wellington and Edward VII. But they were definitely the type.

At the time I was astonished. I was used to hearing about the violence of working-class young men – skinheads, football hooligans, mods and rockers – but I had never heard of, let alone seen, how thuggish the sons of the rich get when you dress them in dickie bows and fill them full of booze.

The police in those days tended to see them as ‘young gentlemen letting off steam’ and let them off with an indulgent talking-to, but in recent years I’m glad to say they’ve started locking them up.

In the meantime, the mob I saw probably went on to become captains of industry, generals or politicians, leading apparently blameless lives in the suburbs or the Home Counties.

Until, that is, they put on a tuxedo.

There’s something about that James Bond class uniform that brings out the worst in the posh.

In January last year, black-tie-clad rich men attended the Presidents’ Club fundraising dinner in London, and felt entitled at the same time to grope, sexually harass and proposition the hostesses at the event.

Then last week, black-tie-clad Foreign Office minister Mark Field grabbed a Greenpeace activist by the neck and slammed her against a wall before forcibly ejecting her from a Mansion House dinner.

There must therefore be something about eating and drinking lavishly while wearing a uniform that reinforces one’s sense of belonging and of entitlement.

Neurologically, the shared experience stimulates the production of the team bonding hormone oxytocin.

The good food, drink and bonhomie will add other pleasurable hormones like endorphins.

So people who have been Bullingdon Boys in their youth, and then pursue careers that involve a lot of black-tie troughing, end up believing they are the natural heirs to the Kingdom.  They might even believe they have a natural right to be Prime Minister.

But the downside of oxytocin is that as well as making you love your tribe, it can turn you against those unfortunates who aren’t in it.

Thus it was that when Mark Field MP was confronted by a surprise deputation of ‘greenies’, he got a primal rush of ‘repel boarders’ in his synapses and reacted as if to an invasion.

Now, if we were talking about the working class, people would be suggesting banning alcohol or stiffer jail sentences.

But we’re not. We’re talking about our rulers.

I would therefore propose a modest piece of legislation.

The nation’s appetite for serious troughing is, on the whole, a Good Thing, so I wouldn’t do anything to stop that.

But I might pass a law against doing it while dressed in a penguin suit.

It seems to give people seriously strange ideas.