Left-wing liberals are just as likely to hold authoritarian views as conservatives, according to a new US study published in the journal Political Psychology.

Lucian Gideon Conway from the University of Montana and his team developed a method to measure left-wing authoritarianism (LWA) by adapting the right-wing authoritarianism (RWA) scale first developed by psychologist Bob Altermeyer.

The RWA involves asking participants how much they agree with statements such as: "The established authorities generally turn out to be right about things, while the radicals and protestors are usually just loud-mouths showing off their ignorance" and "Our country will be destroyed someday if we do not smash the perversions eating away at our moral fibre and traditional beliefs."

On the other hand, the newly developed LWA scale asks questions like: "Our country desperately needs a mighty leader who will do what has to be done to destroy the radical new ways and sinfulness that are ruining us" and "It's always better to trust the judgment of the proper authorities in science with respect to issues like global warming and evolution than to listen to the noisy rabble-rousers in our society who are trying to create doubts in people's minds."

For the study, 305 American adults and 475 undergraduates at the University of Montana were recruited and tested on both scales. The researchers found that left-wing authoritarianism was a valid concept, being associated with prejudice and dogmatism in both groups.

"Our data suggest that average Americans on the political left are just as likely to be dogmatic authoritarians as those on the political right," Conway told PsyPost. "And those left-wing authoritarians can be just as prejudiced, dogmatic, and extremist as right-wing authoritarians."

"I became interested in left-wing authoritarianism, in particular, because some people have said it isn't a very real or likely phenomenon - and yet I know people I would describe as left-wing authoritarians," she said. "So, I was curious to figure that out."

Most psychologists think that authoritarianism in North America may be a uniquely right-wing phenomenon, despite the fact that political extremism can exist on both sides of the spectrum.

There have been a number of attempts to identify left-wing authoritarians in the US and Canada – people who submit to leftist authorities, hold highly conventional liberal viewpoints and are aggressive to those who oppose left-wing ideology - however, these attempts have not always succeeded because measures of authoritarianism have always correlated, at least slightly, with the right.

While research shows that authoritarians in North America tend to support conservative political parties, this should be viewed in its historical and cultural context. During the Cold War, for example, authoritarians in the US were usually anti-communist, whereas in the Soviet Union, authoritarians usually supported the Communist Party and opposed capitalism.

In both cases, left-wing and right-wing authoritarians generally favoured the established authorities and opposed social and political change.

The author's acknowledge that the new research does have its limitations, however.

Firstly, it is a preliminary study with a small and specific sample, meaning more generalised conclusions cannot be drawn. More research will need to be conducted in this area to shed more light on the issue.