Many have tried guessing who first uttered this saying: "If you are not a liberal at 25, you have no heart. If you are not a conservative at 35, you have no brain".

Could it have been Winston Churchill? Victor Hugo, perhaps?

At various points in history, the phrase has been attributed to numerous greats, and the meaning behind it is yet to fade from the public psyche.

The adage seems to ring true to many, and it makes sense why — even if the reality is a little more complex.

The last three-month Newspoll of more than 6,000 respondents ahead of last month's federal election found a large disparity in voting intentions by age group.

According to the poll, among those 50 and over the Coalition had a 44 per cent chance at nabbing the primary vote, with Labor at 35 per cent.

Shift that bracket down to the 18-34s, and Labor had 46 per cent of the primary vote, while just 28 per cent said the same for the Coalition.

Older Australians do not, of course, exclusively vote for right-leaning parties, and the statistics clearly reflect this.

The question arises, then: Why do so many Australians appear to adhere to a famous aphorism attributable to no-one?

Changing demographics could predict future outcomes

There are two main theories that attempt to answer the question of whether older people are generally more conservative.

The first concerns itself with the potential effects psychological ageing has on older voters, and suggests they do become more conservative.

Could ageing prompt an increase in conservatism? ( Unsplash: Soren Astrup Jorgensen )

In 2017, one in seven Australians were 65 or older, according to the Australian Institute of Health and Welfare, and this number is projected to rise.

Given we live in an ageing society, the first theory points towards an increase in the number of voters opting for right-wing parties in the future.

The second theory, meanwhile, suggests belonging to a certain generation has the greatest influence on a person's voting habits, meaning your political beliefs are most likely to align with those of the times.

If this theory has more weight to it, it could tip the balance in favour of voters being more likely to tick the box for left-leaning parties in future.

Why it's hard to tell

However, James Tilley, a professor of politics at the University of Oxford, told the ABC it was "essentially impossible" to choose between the two theories.

It is hard to pinpoint where people's views come from, Professor Tilley says. ( Supplied: Greenpeace )

He said: "If Bob is 42 today, then I also know he was born in 1977.

"Let's say that I compare his support for the death penalty to Jane. Jane is 22 today, and so was born in 1997.

"Any difference between Bob and Jane could be because Bob is older than Jane, or it could be because Bob was born and grew up in an earlier period to Jane. We don't know.

"Similarly, if we track people's views on the death penalty over time, then we cannot be sure why those views have changed.

"It might be because people have got older, but it might be because the death penalty has become less, or more, popular over time."

Generational theory most likely to be right

The best researchers can do, Professor Tilley said, was decide which of the two theories was most plausible.

Researchers are able to separate out the effect of social conservatism — a political ideology that centres on traditional values and established institutions — from everything else, he explained.

"Of course, we cannot say for sure that [changes] in social conservatism are due to generational differences, although that seems most likely," Professor Tilley added.

London School of Economics political sociology professor Robin Archer agreed.

Experts say there is a danger of overstating the importance of generational effects. ( Supplied: State Library of WA )

Pointing to prominent research, Professor Archer said there was a fair amount of evidence to support the generational effects theory on voting.

"[And] if this work is right, then we wouldn't expect to see much of a shift towards conservatism as people age from say their late 20s onwards [given voting habits would already have been formed]," he explained.

However, he insisted there was a "general danger of overstating the importance of [these] generational effects".

"Generational effects can be important, as the UK Brexit referendum shows, but they may not be typical," he said.

Looking to the future, Professor Tilley said the question of whether the majority of older voters would continue turning to parties with conservative values was another essentially impossible one to answer.

"Whether this will continue or not depends on political circumstances and choices by the political parties, which are inherently unpredictable," he said.

