The trend towards the acceptance of authoritarianism is one of a set of symptoms suggesting that what were once thought to be unassailably stable democracies - such the United States or even Australia - are not as healthy as previously thought, according to the political science lecturer Roberto Foa, of Melbourne University, and Yascha Mounk, a lecturer in governance at Harvard University.

The research suggests that the rise of Donald Trump, Pauline Hanson as well as Marine Le Pen in France and Nigel Farage's UK Independence Party are symptomatic of a deeper malaise in the liberal democratic tradition.

The two, who studied as postgraduates together at Harvard, were first alerted to the trend by a colleague who had analysed data from the World Values Survey and found that the tenets of democratic government were being rejected by people in Latin America. The two looked deeper into surveys and found the instability can be found in nations around the world and can be traced back to the 1980s, according to a paper to be published in the January issue of The Journal of Democracy.

They found that the proportion of Americans expressing approval for "army rule" has risen from 1 in 16 in 1995 to 1 in 6 in the most recent survey. The number of Americans who were alive during World War II who believe it is "essential" to live in a democracy stands at 72 per cent, but among millennials that figure has fallen to 30 per cent.

The same pattern can be found in Australia, Britain, the Netherlands, Sweden and New Zealand.

"Citizens are growing more disaffected with established political parties, representative institutions, and minority rights," their paper says. "Tellingly, they are also increasingly open to authoritarian interpretations of democracy.

"The share of citizens who approve of 'having a strong leader who does not have to bother with parliament or elections,' for example, has gone up markedly in most of the countries where the World Values Survey fielded the question - including such varied places as Germany, the United States, Spain, Turkey, and Russia.

"In a German survey, a large majority endorsed democracy 'as an idea,' but only about half approved of 'democracy as it works in the Federal Republic of Germany today,' and more than one fifth endorsed the view that 'what Germany now needs is a single, strong party that represents the people'.

"In France, two-fifths of respondents in a 2015 survey believed that the country should be put in the hands of 'an authoritarian government' free from democratic constraints."

The two researchers developed a three point-test to assess the health of democracies.

They considered firstly how important citizens believed democracy to be for their country, secondly how open they were to non-democratic forms of government and thirdly how much support outsider political players were gaining.

Using the test they were able to look into historical data to detect signs of what they called democratic  "deconsolidating" in nations where democracy later went into retreat, such as Poland and Venezuela.

Dr Mounk told The New York Times  this week the same tests showed that  "the warning signs are flashing red" around the world.

In an interview with Fairfax Media, Dr Foa said middle classes around the world that had seen prolonged wage stagnation, class consolidation and ineffective governance were more drawn to authoritarianism.

He said the election of Mr Trump - a man who had promised to jail his opponent and said he would not accept the result of the election unless he won - was not a normal event in the political life of a liberal democracy.

While the trends can be detected in Australia, Dr Foa says they are less advanced because inequality is not as great and the sense of class exclusion is less profound.  In Australia, he said, "there is still a sense of egalitarianism".

Dr Foa acknowledges that younger people without the same sense of history as their older relatives are more likely to be less averse to authoritarianism.

"People don't have the same negative experience of authoritarian rule and that has led to complacency regarding democracy and democratic stability."

But he said the intergenerational gap was not only linked to age. "We don't see it in transitional countries. In many countries, for example China, it is the opposite, the younger are more pro-democratic. Also it was not as pronounced in the past as it is today."