Michel Barnier is right that the UK needs 'educating', but his comments give more power to Brexiteers

A psychological experiment called the Ultimatum Game exists to demonstrate humankind’s remarkable willingness to cut off its own nose to spite someone else’s face.

A sum of money, let’s say £100, is given to two people. It is left entirely up to person A how it should be divided between the two, but person B holds power of veto. Person A can choose to split the money 50 / 50, or keep £99.99 for themselves and give person B a penny. But if person B is not happy with the amount passed their way, they can decide that the pair of them leave with nothing.

An entirely rational person B, so the psychologists say, should always accept whatever they are given, even if it just a penny. That something is always better than nothing, the other person's fortunes being immaterial to your own.

You will not be shocked to learn, however, that the game rarely plays out this way. Psychologists suggest that it may be the human brain may have worked out that it might be more in its long term interest to preserve fairness and justice in the society in which it lives than meekly to accept less than it is due.

Indeed, it is one of the reasons, according to a TV producer friend of mine, that a cheerfully exploitative reality TV Benefits Street-style version of the game is mercifully yet to make it out of development. In pilot episodes, the propensity of two impoverished families, suddenly given a large cash lump sum, to then shaft each other in the name of supposed fairness, has not made for uplifting viewing.

We turn then to EU chief negotiator Michel Barnier, and his apparent new vocation as told to a conference in Italy at the weekend, to “educate” the British on the price of leaving the European Union. “There are extremely serious consequences of leaving the single market and it hasn’t been explained to the British people,” he said on Saturday. “We intend to teach people what leaving the single market means.”

In so doing he has made loud and clear what was always the most persuasive argument for remaining in the European Union; the one argument that, according to people who didn't have their noses pressed against the political glass during the dismal referendum campaign, they did not hear: that we must remain or the EU will make an example of us.

To be fair to the spectacularly abysmal Remain campaign, it is a difficult argument to make. "These absolute bastards are our friends," is a slogan never likely to be coming to a campaign T-shirt near you.

There are, of course, many complexities to the negotiations, but the central one is that there are two ultimatum games occurring simultaneously. It is fundamentally not the exercise in mutual self-interest the breezily optimistic Brexiteers either pretend or genuinely believe it to be.

The EU is willing to harm itself and the UK to preserve its wider society. The UK is willing to harm itself and the EU too, even though any sane person can see that a bad deal is significantly better than no deal.

Alas, it would appear, the Ultimatum Game is a fundamental failing in the human psyche of which David Davis is unaware.

Whenever Remainers, and Liberal Democrat ones in particular, talk of a second referendum on the terms of exit, Davis and others reject it out of hand with the flawed logic that it will incentivise the EU to offer us a bad deal in the hope the voters will reject it.

What is becoming clearer to see, and Barnier knows it, is that the harsher the deal, the more aggressive, the more arrogant, the more willing the EU shows to punish Britain, the more readily, the more gleefully a large proportion of the population will choose to harm ourselves if we think we can harm them too.

That he appears to see it as his mission to educate Britain and the Eurosceptic corners of other member states on the fundamental folly of leaving the club is simultaneously the best argument against leaving and the vindication of the Brexiteers’ caricature of a vindictive, unaccountable, arrogant superstate.

The harsher the lesson he wishes to teach, the more willingly we will learn it.

The supposed Brexit of mutual self-interest as sold by Messrs Johnson, Hannan, Davis and so on, was never any more than a cocktail of various parts of illusion and delusion, depending on the mixologist.

As the education begins, surely there is no one left still swallowing it.