There is genuine anger at the behaviour of Dominic Cummings not just among the usual suspects but among some Tory MPs such as Roger Gale and Douglas Ross. It's worth exploring why this should be the case.

It's because of cultural evolution. Early humans worked out (or stumbled upon) an important fact, that we often thrive best when we cooperate. As Axelrod and Hamilton showed in a classic paper (pdf):

Cooperation based on reciprocity can get started in a predominantly noncooperative world, can thrive in a variegated environment, and can defend itself once fully established.

Or as Ken Binmore put it in Natural Justice:

We don't need to pretend that we are all Dr Jekylls in order to explain how we manage to get on with each other fairly well most of the time. Even a society of Mr Hydes can eventually learn to coordinate on an efficient equilibrium in an indefinitely repeated game.

This cooperation takes the form of the Golden Rule, or do as you would be done by. As Binmore shows, pretty much all societies have some version of this principle. I agree to obey rules - even at a cost to myself - because I expect you to do so.

But how are such norms enforced? By punishing defectors, that's how. In Axelrod and Hamilton's formal scheme, this takes the form of tit-for-tat strategies. Less formally, we use mockery, ostracism and even violence: "snitches get stitches."

Most of us have internalized these norms. We know this from experiments with the ultimatum game, wherein one player is given some money and can split it with another, with the other choosing to accept or reject the offer. Purely selfish offerers would offer the lowest amount possible, and purely selfish receivers would accept. But this is not what happens. Offers of less than 30-40% are only occasionally made, and often rejected when they are.

This shows that we have a norm of fairness. Offerers don't make unfair offers even if they'd benefit from doing so, and receivers reject such offers even if they'd be financially better off accepting. Both sides do so because the norm of fairness over-rides short-term financial gains.

It's for a similar reason that people leave tips even in restaurants they'll not return to. We feel bad not tipping; we don't want to be thought badly of; and we want to uphold incentives for good service because we'd expect visitors to our regular restaurants to do the same for us.

This, I think explains the anger towards Cummings. It's because people think he has broken one of the oldest social norms, of thinking the rules that apply to us don't apply to him. Millennial of cultural evolution mean this norm is now viscerally internalized. Hence the power of the charge "one rule for them, one for us".

In this context, it is pointless to wiggle about claiming that Cummings observed the letter of the rules. Such legalistic pedantry misses the point - that it is the spirit of the rules that matter.

This also explains Conservatives' disquiet. Some of them genuinely believe in the rule of law - the principle that laws apply to us all, which is part of the Golden Rule. For them, Cummings has broken a core moral principle.

One irony here is that Cummings should have been aware of all this. As he himself wrote:

Most of our politics is still conducted with the morality and the language of the simple primitive hunter-gatherer tribe...Our 'chimp politics' has an evolutionary logic: our powerful evolved instinct to conform to a group view is a flip-side of our evolved in-group solidarity.

Binmore points out that it was in tough times that norms of conformity were most strongly enforced, because it's then that survival requires them. Or as Marshall Sahlins put it:

During lean food seasons the incidence of generalized exchange should rise above average...Survival depends now upon a double-barrelled quickening of social solidarity and economic cooperation. The social and economic consolidation could conceivably progress to the maximum: normal reciprocal relations between households are suspended in favour of pooling of resources for the duration of emergency. (Stone Age Economics, p213-4)

Stone Age man's greater emphasis upon community and solidarity in hard times has a strong echo today. Because we're all suffering from the lockdown, we even more than usual expect everyone to muck in together and so are hostile to defectors.

But it has for decades had another echo. As Ben Friedman showed, in recessions we become more intolerant of outsiders, as solidarity with our tribe increases.

Which leads to an exquisite irony. Having exploited that atavistic sense of heightened solidarity so well during the Brexit campaign, Mr Cummings is now a victim of it. He is being hoist by his own petard. It takes a heart of stone not to laugh.