The millions of protestors in Egypt who have brought down a president will today be experiencing the heady thrill of wielding the ultimate power - the jailing of their own leader. But power distorts thinking and emotions and there are strong lessons from psychology and neuroscience to predict that these crowds may live to regret what they have done.
Of course President Morsi himself had succumbed to power in negative ways, for instance removing judicial contraints on his presidential authority, but the fact is that he was democratically elected and Egypt is now even more divided into two vast pro- and anti-Morsi groups.
Standing shoulder to shoulder with millions in Tahrir Square would have triggered an intense, exhilarating 'high' and feeling of omnipotence. The sense of intense solidarity would have triggered the release in millions of brains of the 'bonding' hormone oxytocin. This too has anti-anxiety properties and triggers the warm glow of fellow-feeling and solidarity with the other members of the group. It also strengthens the effects of power by acting on the brain's same reward circuits as power does.
But the downside of this is that oxytocin makes people more likely to despise those in the other group. Strong in-group feelings such as in the anti-Morsi protesters would have triggered feelings of schadenfreude when they see their rivals suffer; more worryingly, the stronger the in-group feelings, the more likely people are to say that they would be inclined to take action to harm the out-group.
The awful capacity of human beings to make war is linked to this in-group parochialism: evolution favoured tribes where you would help your neighbor within your clan but seek to vanquish those outside it: our genes, in other words, may have thrived on war: and alwar was civil war during the formative periods of our evolution.
But human civilisation developed an ingenious device to curb evolution's hard-wired tendencies and constrain power's individual or mob effects - democracy - with its electoral, judicial and journalistic lieutenants. Morsi may have tampered with the judicial process and his constitution may not have been an optimal protector of democracy, but the fact was that he was fairly elected by a majority of Egyptians.
Being a democrat demands that you always submit your individual will to an abstract principle of democracy: 'I may not like losing, but I respect the democratic process.' What the coup in Egypt does is to damage or even destroy this crucial abstract constraint on the brains of every Egyptian person. And this is important because abstract thinking reduces prejudice against the out-group and thus probably diminishes the risk of inter-group conflict.
Enormous political polarization exists in the USA, with Republican and Democratic tribes expressing mutual repugnance reinforced by an almost universally partisan media. But the democratic mechanisms - and crucially the commitment to the abstract principle of democracy - are sufficiently strongly embedded in the minds of enough citizens and politicians that the tribal hatreds in the USA are unlikely to be acted out on the streets.
This is unfortunately not the case for Egypt: in one sweep a single abstract principle of commitment to the ideal of democracy, has been swept away. This will have far-reaching effects which will ensure that the cocaine-like high of mob power is temporary.