Gwynne Dyer is a Canadian-born independent journalist whose column is published in more than 175 papers in 45 countries.

At first I was going to write about the ‘Arab Problem’, because there is not a single functioning democracy in the Arab world. This week’s presidential coup in Tunisia has probably ended democracy in the one country that actually achieved it during the ‘Arab Spring’ of 2010-11.

In Syria and Yemen and Libya, attempted democratic revolutions led to dreadful civil wars – and now Lebanon, the closest thing to an Arab democracy for most of the past century (though always dysfunctional) is actually collapsing. In a once prosperous country, many people are close to starving, and desperate Syrian refugees are going back to live under Assad’s regime.

The Arab world is an outlier, but not very far out. Consider the Philippines, a genuine democracy with a president who was legally elected five years ago and will soon leave office peacefully at the end of his one permitted term.

Rodrigo Duterte is also, by his own admission, a mass murderer whose death squads have killed thousands of people.

Some were real drug-dealers and some were ‘false positives’, but in all that time Duterte’s public approval ratings have never fallen below 70%. There are a lot of people who will admire a ‘strong’ leader, even if he is a killer.

Leaving actual killers aside, the ‘alpha male’ model of leadership still in many countries that are formally democratic: Putin in Russia, Orban in Hungary, Erdoğan in Turkey. Even genuine democracies of long standing can be seduced by a ‘great’ leader, like De Gaulle in France. (No, I don’t know where Trump fits in this Pantheon.)

And yet at the same time we have countries that remain democratic even under great pressure, like Brazil under Bolsonaro, South Africa under Zuma, or Indonesia ever since Suharto. The question is not why does democracy fail or why does it succeed? It’s why does it do both?

The only people who have plausible answers are the people who study human nature: the psychologists and sociologists, of course, but more importantly the anthropologists, the primatologists and the ethologists. Many of them would argue that the human race has a dual heritage.

We are members of the primate family and particularly close to the chimpanzees, whose little societies are generally tyrannies run by an alpha male. The other members of the group have strong submissive reflexes to protect them from his bullying (but the subordinate males are also constantly making alliances and seeking to dethrone him).

But our own species, homo sapiens, spent most of its career living in egalitarian groups of fewer than one hundred people. They had no formal leaders, they made their decisions by consensus, and they shared almost everything. How do we know? Because all the hunter-gatherer bands who survived into the recent past lived that way.

When we moved into the mass societies around five thousand years ago (‘civilisation’), we had to go autocratic, because you couldn’t run a group with thousands or even millions of people by consensus. There was no way to include everybody in the discussion.

So five thousand years of tyranny – but as soon as we got mass communications (just printing, to begin with), the egalitarian model started coming back, because we are more comfortable with it.

We call it democracy now, and it certainly does not mean absolute equality. It does mean that the differences of wealth and power must not become too great, or the whole structure of consent will collapse and we’re back to autocracy. Nevertheless, democracy is the default mode.