What has caused the rise in populism that's threatening the mainstream political parties around the developed world, including here?
Economists tend to explain it essentially in economic terms – the bottom has been given a rough deal for years, and finally is rising up – but other scholars see it much more in social and cultural terms: people objecting to being overrun by incomers. Immigrants, asylum seekers, Mexicans, Muslims, Asians.
In his new book for the Lowy Institute, Choosing Openness, Parliament's most accomplished economist, Dr Andrew Leigh, also Labor's shadow assistant treasurer, readily acknowledges the role of xenophobia in explaining why "openness makes us uncomfortable".
He sees our fear of foreigners as part of our evolutionary make-up, and I don't doubt he's right.
Drawing on the work of British anthropologist Robin Dunbar, he argues that "for most of history, humans lived in groups of about 150 people" – a figure known as "Dunbar's number".
Such groups were big enough for some specialisation, but small enough for everyone to know and trust everyone else. People were born, mated, hunted and died within their small community.
"In this environment, there were two kinds of people: those in your tribe and those not in your tribe," Leigh says.
"It made sense to take care of your tribal members. You shared a lifelong relationship with them. Thanks to inbreeding, the rest of the tribe probably looked a lot like you and you certainly all dressed alike.
"Conversely, outsiders were likely to look a bit different and were probably dangerous. While some groups traded, killing was extremely common."
One in seven people in these kinds of societies met their end as a result of violence by another person, he says.
For about 99 per cent of the time that homo sapiens have been on the planet, most of us have lived in small groups. As a species, that is what we evolved to do.
"Each of us is here today because our primitive ancestors were skilled at either fighting outsiders or avoiding conflict. The rule that 'different equals dangerous' kept our forebears alive."
But while hunkering down in the face of difference might have been a useful evolutionary strategy in the past, the growth of cities changed the equation, Leigh argues.
Cities are bound together by not by familial relationships, but by rules and norms of acceptable behaviour.
For hundreds of years, the most productive cities have been those that welcome visitors. In a primitive tribe, a dislike of difference can keep you alive. In a city, it's likely to just make you poorer.
"In this sense, a distrust of diversity is a bit like wisdom teeth – an evolutionary vestige that once helped us grind up plants, but now are more likely to take us on a trip to the dentist's chair."
Today's backlash against openness, Leigh argues, shows how humans' natural discomfort with difference can be exploited for political gain.
In a seminal study of the politics of hatred, the Harvard authority on urban economics Edward Glaeser noted that the key to building a powerful coalition around hate is to focus voters' anger on an "out group" that is sufficiently large to be taken seriously as a threat, but too small to be electorally decisive.
Remind you of any redheads you know?
So Leigh says that populism – the idea that politics is a conflict between the pure mass of people and a small vile elite – is the product of four main forces.
First, slow growth in living standards when the proceeds of economic growth haven't been shared.
"In societies where prosperity is broadly shared, a cosmopolitan outlook steadily replaces traditional values of religion, deference to authority, and an exclusive focus on the security of our family and tribe," he says.
Second, populism is fostered by the pace at which society and technology are changing. Voters may turn to extreme politics as a way of saying "Stop the world – I want to get off."
Third, populism has benefited from canny political entrepreneurs – Duterte, Erdogan, Trump – able to generate massive free media coverage by attacking rivals and breaking taboos.
Fourth, populism has grown because of a loss of faith in mainstream centrist parties. (Their ever-declining standards of behaviour would have nothing to do with this, of course.)
In the late 1960s, seven out of 10 Australians said they always voted for the same party. Today, the share of party loyalists is down to four in 10.
Seems to me that, though much of the problem is manifest in fear of foreigners, the best way to strengthen cosmopolitan values is to ensure the benefits of globalisation and technological change are shared more fairly.
